main-content

This book comprises selected peer-reviewed proceedings of the International Conference on Applications of Fluid Dynamics (ICAFD 2018) organized by the School of Advanced Sciences, Vellore Institute of Technology, India, in association with the University of Botswana and the Society for Industrial and Applied Mathematics (SIAM), USA. With an aim to identify the existing challenges in the area of applied mathematics and mechanics, the book emphasizes the importance of establishing new methods and algorithms to address these challenges. The topics covered include diverse applications of fluid dynamics in aerospace dynamics and propulsion, atmospheric sciences, compressible flow, environmental fluid dynamics, control structures, viscoelasticity and mechanics of composites. Given the contents, the book is a useful resource for students, researchers as well as practitioners.

### Deriving Shape Functions for a 20-Nodal Tri-quadratic Serendipity Element and Verified

In this paper, I derived shape functions for a 20-nodal tri-quadratic serendipity element which consists of eight corner nodes and twelve mid-side nodes using natural coordinate system. I derived two shape function verification conditions, first verification condition sum of all the shape functions is equal to one, and second verification condition each shape function has a value of one at its own node and zero at all other nodes. For mathematical computations, I used Mathematica 9 Software.

P. Reddaiah

### Cosinusoidally Fluctuating Temperature and Chemical Reacting Effects on MHD-Free Convective Fluid Flow Past a Vertical Porous Plate with Hall, Ion-Slip Current, and Soret

In this paper, an exact solution and cosinusoidally fluctuating temperature of unsteady MHD-free convective flow through an infinite moving vertical permeable plate with hall, ion-slip current, and chemical reaction as well as soret effects has been analyzed. The exact solution of the governing equations was attained using perturbation method. The influence of dissimilar parameters on velocity, temperature as well as concentration fields is stated graphically. In this investigation, it was conclude that as rise in hall and ion-slip current parameter leads to rise in velocity, but contrast effect was occurred in case of heat source and Prandtl number. In addition, concentration and velocity are declined with rise in Reynolds number and soret parameter.

K. S. Balamurugan, K. V. B. Rajakumar, J. L. Rama Prasad

### Fluid Motion in Finite Length Tubes in Peristaltic Pumps

We considered the flow of an incompressible Newtonian fluid within a finite tube, which is driven by multiple train waves or a single peristaltic wave. The solutions of the governing equations were taken as a pertubation series with pertubation parameter being the wave number. These infinite series were truncated at the first corrective term. Expressions for the axial and transverse conponents of the velocity, the pressure, the shear stress at the walls as well as the volume flow rate were obtained. From this study, the effects of the wave number, the occlusion of the tube, the wave amplitude, as well as the wave type were analyzed. It was observed that the pressure distribution is affected by the wave type, the time-averaged volume flow is slightly affected non-integral number of waves and is independent of the axial position for the case of multiple train waves. However, in the case of single wave, the time-averaged volume flow depends on the axial position and we saw reflux at the entrance of the tube even for co-pumping conditions. Also, changes in the wave number resulted in tranformations of the plots of the results which became more obvious for highly occluded tubes.

André Small, P. Nagarani

### Hall Effects on MHD Rotating Nano Fluid Over a Moving Flat Plate with Radiation and Chemical Reaction

In this manuscript, we have deliberated an unstable free convection stream of Nano fluid limited with a “moving vertical flat plate” through a porous medium in revolving framework with conditions of diffusion and convection and also bringing current of Hall into account. We acknowledged two kinds of Nano fluids: they are TiO2–water and Ag–water. The governing equations would be illuminated analytically by utilizing the method of perturbation. Last, the impacts of different dimensionless factors on temperature, velocity, and concentration profiles along with Sherwood numbers, shear stress, and local Nusselt are deliberated with support of graphs.

Pushpabai Pavar, L. Harikrishna, M. Suryanarayana Reddy

### An Analytical Study of Aerosol Dispersion in the Atmosphere Bounded by Porous Layers

The mathematical model is developed using analytical method to examine the effects of aerosol dispersion in atmospheric fluid, both in the presence and absence of chemical reaction. Its applications are in many fields especially to human health, environmental pollution, and climate change. Taylor’s dispersion model is applied to study aerosol dispersion in a channel bounded by porous layers with applied electric and magnetic field. It is perceived that the presence of chemical reaction intensifies the aerosol dispersion while in the absence of chemical reaction, the aerosol dispersion reduces.

P. Meenapriya, K. Uma Maheswari

### Solution of Gas Dynamic and Wave Equations with VIM

In the present research paper, we will solve homogeneous and non-homogeneous gas dynamics equation, KdV, K (2, 2) equations and wave equation with different boundary conditions. In the current research paper, to arbitrate solutions for KdV, the K (2, 2) and the wave equation reliable iteration approach is taken into consideration. We apply VIM to solve all the equations. The study highlights the efficiency of the approach and its confidence on the Lagrange multiplier. This work completes the coordination of KdV condition by the guide of any other strategy. This prompts the unpredictable answers for the condition of homogeneous and non-homogeneous gas dynamics equation, KdV and wave equations.

Nahid Fatima

### Comparison Analysis Through Condition Monitoring for Fault Detection of Bearing in Induction Motor

In Industries, maintenance is an important activity to keep the equipment in a healthy condition. Condition-based maintenance (CBM) is a proactive maintenance technique that helps to fault diagnose of a machine system in running condition. This program is carried out in three steps: (i) detection; (ii) analysis; and (iii) correction. In CBM techniques, vibration analysis plays a vital role in identifying problems. The objective of this paper is to perform a comparison analysis of newly replaced bearings and corrected misaligned shaft for 630 kW induction motor with already existing healthy condition induction motor. This is done by vibration monitoring technique using fast Fourier transform (FFT) analyzer. The main attraction of this technique is that it can be performed even while the equipment is in normal working condition, thus saving precious downtime and avoiding production loss. This technique helps in diagnosing motor health by taking readings on drive end and non-drive end for both motors. By placing the accelerometer sensor in the tri-axial direction of motor vibration, data is obtained. These are in amplitude and time waveform signals and are collected at full load condition. This comparison analysis is a technique that helps to know the motor health condition. The obtained results are encouraging and identified the motor rolling bearing health status in running condition.

Y. Seetharama Rao, Devarabhotla Sai Chandra

### Influence of Thin Baffle and Magnetic Field on Buoyant Convection in a Vertical Annulus

This paper numerically investigates buoyancy-driven convection in an annular cavity having differently heated cylindrical side walls and a thin baffle attached to the inner cylinder. The annular enclosure is packed with electrically conducting low Prandtl number fluid (Pr = 0.054). Along the radial or axial direction, a magnetic field of uniform intensity is applied. The finite difference method consisting of ADI and SLOR techniques is employed to solve the model equations governing the physical processes. The simulation results are presented through streamlines, isotherms, local, and average Nusselt numbers to illustrate the effects of various parameters. The simulation results explain that the Hartmann number and baffle length restrained the heat transfer rate, while the Rayleigh number and baffle location enhance the rate of heat transfer.

B. V. Pushpa, M. Sankar, B. M. R. Prasanna, Zailan Siri

### Study of Rayleigh-Bénard Convection of a Newtonian Nanoliquid in a Porous Medium Using General Boundary Conditions

In the paper we make a linear stability analysis of Rayleigh-Bénard convection (RBC) in a Newtonian, nanoliquid-saturated porous medium. Single-phase model is used for nanoliquid description and values of thermophysical quantities concerning ethylene glycol-copper and the saturated porous medium it occupies are calculated using mixture theory or phenomenological relations. The study is carried out using general boundary conditions on the velocity and temperature. The Galerkin method is used to obtain the critical eigen value. The results of free-free, rigid-free and rigid-rigid isothermal/adiabatic boundaries are obtained from the present study by considering appropriate limits. The results of the limiting cases of the present study are in excellent agreement with those observed in earlier investigations. This problem is an integrated approach to studying Rayleigh-Bénard convection covering 34 different boundary combinations.

P. G. Siddheshwar, T. N. Sakshath

### Rotary Oscillations of a Permeable Sphere in an Incompressible Couple Stress Fluid

In this paper, an attempt is made to study the flow generated by rotary oscillations of a permeable sphere in an infinite expanse of an incompressible couple stress fluid. The flow generated is solved under Stokesian assumption for velocity field in the form of modified Bessel functions. The couple acting on the sphere due to external flow as well as internal flow is calculated. The couple has contributions to both couple stress tensor and stress tensor. Contour for the flow at different couple stress parameters is drawn to analyze the flow. It is noted that, due to couple stresses, the particles near the surface of the sphere are thrown away with velocity more than the velocity of the surface of the sphere. Comparative study of type B and type A conditions is presented through pictorial representations.

P. Aparna, N. Pothanna, J. V. R. Murthy

### Simulation of Natural Convective Heat Transfer in a Triangular Enclosure Filled with Nanofluid: Buongiorno’s Mathematical Model

Natural convection of triangular enclosure filled with water-based nanofluid under the influence of Brownian diffusion and thermophoresis is studied numerically in two cases by depending on wall boundary conditions. The high (hot) temperature vertical wall and the insulated bottom wall are considered in case (i) and the other case the bottom wall is uniformly heated while the vertical wall is thermally insulated. In both cases, the inclined wall is maintained low temperature (i.e., cold inclined wall). The coupled governing vorticity–stream function formulation equations are employed by the help of finite difference method (FDM). The influence of the Rayleigh number, Lewis number on fluid flow, heat have been examined through graphically and discussed. It has been found that in the case of uniform heating is high sensitive to rising of the Ra, while the uniform heating of the left wall of the cavity is not so sensitive to changes of Ra.

K. Venkatadri, V. Ramachandra Prasad, B. Md. Hidayathulla Khan, M. Suryanarayan Reddy, R. Bhuvanavijaya

### Influence of Ohmic Heating and Viscous Dissipation on Steady MHD Non-Newtonian Mixed Convective Fluid Flow Over an Infinite Vertical Porous Plate with Hall and Ion-Slip Current

Impact of Hall and ion-slip on steady MHD (non-Newtonian fluid) Casson fluid model based on mixed convective dissipative Casson fluid model flow over an infinite vertical permeable plate with Ohmic heating in aspect of soret as well as chemical reaction has been presented. The modelling equations are transformed into dimensionless equations and then solved analytically through multiple regular perturbation law. Computations were carried out graphically to examine the behaviour of fluid velocity, temperature, and concentration on the vertical plate with the difference of emerging physical parameters. This study reflects that the incremental values of Casson fluid parameter and Schmidt number lead to reduction in velocity. However, fluid velocity rises due to enhancement of ion-slip parameter, but reverser effect has been shown in case of Hall parameter.

K. V. B. Rajakumar, M. Umasankara Reddy, K. S. Balamurugan

### Effect of Rotation and Fluid on Radial Vibrations in a Micropolar Elastic Solid Having a Fluid-Loaded Spherical Cavity

The main objective of this study is to investigate the angular rotation effect of the solid and density of the fluid on the radial vibrations in an unbounded micropolar elastic solid with a fluid-loaded spherical cavity. The micropolar elastic solid is homogeneous and isotropic, but the loaded fluid is homogenous, isotropic, and in viscid. Dispersion relation for radial vibrations of macro-displacements is derived and which is influenced by the loaded fluid and angular rotation of the solid, while the micro-rotational vibrations are not influenced by the loaded fluid and angular rotation. All these results are not obtained in any classical theory of elasticity. Under the MATLAB program, the numerical computations for a particular solid have been performed and have also been shown graphically to understand the effect of angular rotation of the solid and density of the loaded fluid on the behavior of phase velocity and dispersion relation.

K. Somaiah

### Convex Cylindrical Surface-Modified Rayleigh Waves

In this paper, we consider the effect of curvature on the surface wave propagation in a micromorphic medium. It is interesting to observe that the additional waves found in the study of surface waves with curved boundary are dispersive without any cutoff frequency.

A. Chandulal

### Modelling Third-Grade Liquid Past Vertical Isothermal Cone with Variable Temperature and BIOT Number Effects

The non-similar natural convection flows of an incompressible viscoelastic fluid past an isothermal cone with BIOT number effects and variable temperature are investigated. The Keller-Box technique is utilized to solve the transformed conservation equations subject to physically appropriate boundary conditions. The variations of different emerging dimensionless parameters on velocity, temperature, skin friction coefficient and heat transfer rate profiles are presented.

S. Abdul Gaffar, V. Ramachandra Prasad, B. Md. Hidayathulla Khan, K. Venkatadri

### Nonlinear Kelvin–Helmholtz Instability of Viscous Fluids with Heat and Mass Transfer

A nonlinear stability analysis of novel Kelvin–Helmholtz instability of two superposed viscous fluids is performed. We are allowing transferring of heat/mass at the juncture of two fluids. The multiple timescale expansion method is utilized to study various modes of instability. The stability of arrangement is finally governed by a partial differential equation which is nonlinear in nature. The stable/unstable zones are represented graphically showing the impacts of physical variables. The nonlinear analysis shows that transferring of heat at the juncture of two fluids induces instability, while nonlinearity induces stability.

Rishi Asthana, Mukesh Kumar Awasthi

### Influence of Ion-Slip and Hall Current on Magneto Hydrodynamic Free Convective Flow Past an Accelerated Plate with Dufour Effect and Ramped Temperature

An analytical solution is proclaimed the significance of ion-slip and Hall current on magnetohydrodynamic convective free flow of radiation absorbing as well as a chemical reacting fluid past an accelerated affecting vertical porous plate with ramped temperature and Dufour effect. The modelling equations are reformed into dimensionless equations, further illuminated systematically by multiple standard perturbation law. Appraisals were operationalized graphically to scrutinize the performance of fluid velocity, temperature as well as concentration on the vertical plate by means of the disparity of emerging physical parameters.

G. Dharmaiah, K. S. Balamurugan, K. V. B. Raja Kumar

### Effect of Permeable Boundaries on the Flow of a Jeffrey Fluid in a Channel of Varying Cross-Section

In this paper, the flow of a simplest Non-Newtonian fluid in a channel of varying cross-section with permeable boundaries is investigated. The paper finds its significance in understanding the flow of Bio-fluids in the ducts of varying cross section. Perturbation technique is used to solve the governing equations of the flow phenomenon. The expressions for velocity, flow rate, wall shear stress, and the pressure drop are derived. The flux is a function of external pressure, Jeffrey parameter, and the permeability parameter. Further, if $$\lambda_{1} \to 0$$ our results agree with Krishna Prasad and Chandra (Proc Nat Acad Sci 60(A) III: 317–326, 1990 [1]). Mathematica software is used find the pressure, which place a vital role in varying cross sections. Shear stress increases with increasing effects of permeability and Jeffrey parameters which is observed graphically. It is noticed that shear thinning reduces the wall shear stress and this point is stresses in the paper as well. This work helps the young researcher to develop interest in the field of Bio-fluids with varying cross-section.

### Marangoni Convection of Titanium Dioxide/Ethylene Glycol Dusty Nanoliquid MHD Flow Past a Flat Plate

The effects of magneto hydro dynamic Marangoni convection flow of titanium dioxide/ethylene glycol dusty nanofluid past a flat plate is investigated for the first time. The surface tension is required to change directly with temperature. Titanium dioxide/ethylene glycol dusty nanofluid has been enlisted for the improvement of heat transfer rate. By using appropriate similarity transformation for dusty nanoliquid, dimensionless non-linear ordinary differential equations are reformed from the governing equations. The physical parameters for temperature and velocity fields are inspected graphically and elaborately conversed numerically. The heat transfer rate values for the physical parameters are illustrated and tabulated. The average Nusselt number has been enhanced by the Marangoni flow.

N. Indumathi, A. K. Abdul Hakeem, B. Ganga, R. Jayaprakash

### Aligned Magnetic Field Effect on Unsteady MHD Double Diffusive Free Convection Flow of Kuvshinski Fluid Past an Inclined Moving Porous Plate

The current paper scrutinizes the sway of the aligned magnetic field and Kuvshinski fluid model on unsteady MHD free convective flow past a moving inclined plate in the occurrence of thermal radiation as well as radiation absorption with chemical effect and mass blowing or suction. It is implicit that the plate is entrenched in a uniform porous medium moving with a steady velocity in the flow direction and in the existence of a transverse magnetic field. Perturbation technique was employed for solving non-dimensional governing equations. Significant consequences with regard to embedded parameters are illustrated graphically for the temperature, velocity, and concentration profiles. The expression for the Skin friction coefficient is also obtained.

J. L. Rama Prasad, K. S. Balamurugan, S. V. K. Varma

### Nonlinear Radiative Williamson Fluid Against a Wedge with Aligned Magnetic Field

The foremost importance of this presentation is to explore the nonlinear thermal radiation on a Williamson liquid model on a wedge in the company of a heat generation/absorption which is not uniform. An aligned magnetic field, Brownian diffusion and thermophoresis aspects are also investigated. The flow and temperature equations are derived and solved by Runge–Kutta based MATLAB bvp4c solver. Results for different flow characteristics are plotted through graphs and discussed in detail. The wall temperature raises as temperature ratio parameter increases and results in a deep penetration for temperature. The concentration of the species seems to be increased with Brownian diffusion and radiation.

K. Subbarayudu, L. Wahidunnisa, S. Suneetha, P. Bala Anki Reddy

Girish Hariharan, D. Srikanth Rao, Raghuvir Pai

### Influence of Aerodynamic Parameters on Dragonfly Inspired Corrugated Aerofoil

This work is focused on the variation of corrugation angle and peak height of 2-D corrugated aerofoil inspired from the forewing of ‘Pantala Flavescens’ or yellow dragonfly basal wing section. A computational analysis is done on a newly designed dragonfly corrugated aerofoil wing-A and wing-B at Re = 15.603 × 103 and the flow is considered as steady and density of the flow is constant. In this study, the aerodynamic performance of 2-D dragonfly corrugated aerofoil is performed at different angle of attack (AoA) with variation in corrugation angle and peak height. With the varying peak height and corrugation angle, there is low wake formation, reduced drag, and increase in flight performance compared to streamlined aerofoil and flat plate. The computational fluid dynamic (CFD) analysis is performed using a high fidelity fluent solver. The CFD result shows that the aerodynamic performance, i.e., the gliding ratio $$\left( {\frac{{C_{L} }}{{C_{D} }}} \right)$$ of wing-A is higher than wing-B and streamlined aerofoil. The vortex formed is trapped inside the valleys which re-energizes the flow and delays separation leads to an increment in lift coefficient (CL). This finding enhances the knowledge of insect-inspired corrugated wing structure and facilitate the application for improved design of artificial wings for MAVs and UAVs.

### Computational Analysis of Unsteady MHD Flow of Third Grade Fluid Between Two Infinitely Long Porous Plates

In current work the unsteady MHD flow behaviour of a fluid of grade three between two infinitely long flat porous plates is scrutinized where the top lamina is fixed and the lower lamina moves with a velocity which vary with respect to time. Then the non linear p.d.e governing the flow behaviour are reduced to a system of algebraic equations using fully implicit finite difference scheme and numerical solution is obtained using damped-Newton method, which is then coded using MATLAB programming. Influence on velocity with variations in m, $$\alpha$$ , $$\gamma$$ , Re is interpreted through different graphical representation.

### Interaction of Oblique Waves by Base Distortion on a Permeable Bed in an Ice-Covered Sea

The problem involving diffraction of oblique water waves by a little base distortion over permeable sea-bed is investigated in this paper. The top surface of the sea is covered by a lean uniform ice-sheet, where the base of the sea is of permeable type with a little base distortion. The problem is solved by utilizing the Fourier transform method and the 1st-order correction of the reflection and transmission coefficients are calculated. Here, two special kinds of base distortion are taken to calculate the aforesaid coefficients. The values of both reflection and transmission coefficients acquired in this paper are obtained to fulfill the energy identity almost precisely.

S. Khuntia, S. Mohapatra

### Nonlinear Unsteady Marangoni Convection with Variable Properties

The analysis of thin film flow of non-Newtonian fluid with MHD heat transfer in an unsteady stretching sheet in the suspension of variable thickness and thermal conductivity. The governing PDEs are reduced to nonlinear coupled ODEs by applying the appropriate similarity transformations. These coupled nonlinear ODEs subject to the suitable margin conditions and then solved numerically via RK with shooting method. The influences of various parameters on the stream and heat transfer behaviour of the problem are studied through tables and graphs. The friction factor and reduced Nusselt number are obtainable in tables.

M. Sathish Kumar, C. S. K. Raju, S. U. Mamatha, B. Rushi Kumar, G. Kumaran

### Thermo-Diffusion and Diffusion-Thermo Effects for a Forchheimer Model with MHD Over a Vertical Heated Plate

Heat and mass transfer for a Forchheimer model of electrically conducting fluid with Soret and Dufour effects over a vertical heated plate is studied. The governing equations for the physical problem in consideration are highly coupled and nonlinear in nature. A shooting technique is applied to the first-order ODEs’ which are obtained by using similarity transformations to PDEs’ and then to higher-order ordinary differential equations. The effects of various non-dimensional significant parameters such as Richardson number, Prandtl number, magnetic parameter, Soret and Dufour parameters and so on are interpreted. Attenuation with the velocity of fluid flow occurs due to the cause of magnetic force. The diffusion effects which are crossed in the energy and solutal equation enhance the thermal effects. Skin friction, rate of heat, and mass transfer are also computed. Results obtained are compared with the existing work and found to be in good agreement.

N. Nalinakshi, P. A. Dinesh

### Chemical Reaction-Driven Ferroconvection in a Porous Medium

The effect of chemical reaction on the outset of convection of a ferromagnetic fluid in a horizontal porous layer which is heated from below is studied using small perturbation method. Assuming an exothermic zero-order chemical reaction, the eigenvalues are found by employing the Galerkin method. The effect of magnetic parameters and Frank-Kamenetskii number is discussed. It is established that both magnetic forces and chemical reaction accelerate the threshold of ferroconvection. Further, the fluid layer is destabilized marginally when the nonlinearity of magnetization is strong enough.

Nisha Mary Thomas, S. Maruthamanikandan

### Nevanlinna Theory for Existence of Meromorphic Solution to Stuart-Landau Equation

We employ the Nevanlinna theory to investigate the existence of meromorphic solution of the Stuart-Landau equation that is widely used to model supercritical bifurcations occurring in flow systems. We consider the corresponding complex differential equation with sharing value one counting multiplicity or ignoring multiplicity.

A. Tanuja, P. G. Siddheshwar

### Influence of Heat Generation/Absorption on 3D Magnetohydrodynamic Casson Fluid Flow Over a Porous Stretching Surface

The objective of this numerical analysis is to describe the motion of a magnetohydrodynamic non-Newtonian fluid flow generated by a linear stretching surface with porous medium. The shear stresses defined for Casson fluid model are reduced into the form of nonlinear ODEs with the help of similarity transformations. The translated equations are solved numerically by applying shooting technique along with RKF algorithm. The results are examined for distinct values of physical parameters and are displayed through graphs. It is found that the magnetic field and heat generations are responsible for high heat transfer rate in the fluid flow.

Nainaru Tarakaramu, P. V. Satya Narayana

### Radiation and Chemical Reaction Effects on Unsteady Eyring–Powell Nanofluid Flow Over a Moving Surface

The influence of heat source and radiation on magnetohydrodynamic, chemically reacting non-Newtonian nanofluid flow generated by a moving surface is analysed in this study. This nanofluid mathematical model is defined based on Brownian motion and thermophoresis effects. The similarity variables are adopted to convert the governing flow equations into coupled ODE’s and hence solved by the RKF method with shooting technique. The distribution of different flow parameters on the flow, energy and species concentration is discussed and displayed graphically. The results revile that the drag coefficient and rate of heat transfer of the liquid along x-axis decrease for higher values of stretching parameter. In addition, the suction parameter shows an opposite behaviour on the above-said flow variables. The outcomes appear to be same with those of outstanding publicised results as a special limiting case.

Nainaru Tarakaramu, P. V. Satya Narayana

### Parametric Investigation of Beta Type Stirling Engine

Stirling engines are one of the ideal candidates for the conversion of solar power to work since they can efficiently convert low-grade heat into mechanical work. However, there are a few challenges regarding the operation and control of the Stirling engines which need to be resolved before they can be deployed widely. Numerical modeling can be employed to supplement the experimental investigations in obtaining a deeper understanding of the intricacies in the operation of a Stirling engine. In this paper, a mathematical model is developed to accurately simulate a Stirling Engine of beta configuration with a rhombic drive mechanism. The model is formulated by combining the kinematic analysis of the engine mechanism and thermodynamic analysis of working fluid in the engine along with analysis of other transport phenomena occurring inside the engine viz. heat and mass transfer. The model is verified by comparing the predictions against the results published in the literature. The model is then used to conduct a parametric analysis to assess the influence of various operating parameters on the efficiency and power output of the Stirling engine.

H. Raghavendra, P. Suryanarayana Raju, K. Hema Chandra Reddy

### Experimental Approach and CFD Analysis on Flow Devices

This paper deals with the study of experimental approach and investigation by using computational fluid dynamics (CFD) on various flow devices. An orifice meter, venturimeter and a nozzle meter are the most common type of measuring devices used for rate of flow by creating the differences in velocity and pressure. Pressure drop is an important parameter occurring in these flow devices, which is due to restricted passage of flow, properties, diameter ratio, etc. The focus here is to calculate the coefficient of discharge and other flow parameters to analyze theoretically with the application of Bernoulli’s equation. The main objective of this paper is to analyze the variations across the sections of orifice meter, venturimeter and nozzle meter. Comparison of results by both experimental and computational methods was clearly understood, and also, the flow level was calibrated by calculating the coefficient of discharge in both the methods.

S. Gowtham Sanjai, Vishal Suresh, Raman Bedi, A. Sumanthran

### Power Law Lubricant Consistency Variation with Pressure and Mean Temperature Effects in Roller Bearing

The present paper squarely aims to scrutinize the normal velocity of a hydrodynamic lubrication of roller bearings. The changes that happen in lubrication consistency due to pressure and temperature are shown in figures and tables. Further, hydrodynamic lubricant pressure, film temperature, mean film temperature, load and traction for different consistency index n and squeezing velocity q are calculated and compared with the previous results. Those results are positively agreed with the previous findings.

### Second-Order Slip and Thermal Jump Effects on MHD Flow of Nano-second Grade Fluid Flow Over a Stretching Sheet

The present examination is for the most part centered on the flow of a magnetohydrodynamic nano-second grade fluid over a stretching sheet implementing the second-order slip and thermal jump model. To analyze the problem elaborately, numerical simulations are carried out. For that, the partial differential equations that were employed to characterize the flow were transformed to ordinary differential equations with the aid of similarity transformations. Solving them with the much known Runge–Kutta strategy in association with shooting iteration technique, the outcomes for the nano-second grade fluid velocity, temperature, concentration, the local skin friction coefficient, the local Nusselt number and the local Sherwood number are discussed. Some of the notable results of second grade, thermophoresis and Brownian motion parameters along with Lewis number are brought out, which might be relevant for future research work.

P. Ragupathi, S. Saranya, A. K. Abdul Hakeem

### Dampers to Suppress Vibrations in Hydro Turbine-Generator Shaft Due to Subsynchronous Resonance

There are numerous applications to evaluate the damage caused by subsynchronous resonance (SSR) to a turbine-generator shaft. Despite multiple applications, there are relatively few studies on shaft misalignment in the literature. In this paper, stresses in the existing turbine-generator shaft due to subsynchronous resonance were studied using finite element analysis (FEA). The 3D finite element model reveals that the most stressed part of the shaft is near the generator terminal. A new nonlinear damping scheme is modeled to reflect the torsional interaction and to suppress the mechanical vibration caused by subsynchronous resonance (SSR). Stresses developed due to the addition of capacitors in the system at high rotational speeds and deformation of the shaft during various modes of oscillations were evaluated. Experimental investigations are carried out in reaction turbine connected to a 3 kVA generator. Simulation is carried out for the experimental setup using ANSYS. According to the simulation results, the damper installed near the generator terminal provides satisfactory damping performance and the subsynchronous oscillations are suppressed.

Pounraj Manikandan, Faheem Ahmed Khan

### Distribution of Temperature and Thermal Stresses in Unidirectional Rod with Moving Point Heat Source

The present paper comprises the quasi-stationary, non-homogeneous thermoelastic problem with a second kind boundary condition in two-dimensional rod of isotropic material. The unidirectional rod is examined with the condition that ambient and initial temperature is zero. The rod has been observed under the activity of moving heat source located at $$x^{{\prime }}$$ moving with constant velocity along x-axis. Heat conduction equation is evaluated by using integral transform technique. The three materials, viz. aluminum, copper, and brass, have been studied, and the same are analyzed numerically and graphically for their respective thermal stresses. For aluminum, the change is observed from maximum to minimum stress. The response of copper to change in temperature is linear. The curve of copper shows constant value of stress because of its larger coefficient of thermal expansion. Tensile stress is reduced in copper. Minimum stress is observed in brass that indicates the hardness and tensile strength of brass.

Yogita M. Ahire, Kirtiwant P. Ghadle

### Effect of Height of the Tornado Chamber on Vortex Touchdown

Numerically modeled vortex chamber, both in 2D and 3D, have been employed to analyze the flow features of tornado-like vortex. In 2D analysis, flow structure was first investigated using a fixed overall height and varying swirl ratios (S) followed by the variation of overall chamber height to observe its effect on touchdown S. Increasing overall chamber height lowered the touchdown S. Ground pressure profile showed some contrast from experiment as the pressure was found to be increasing even after touchdown. A tentative projection of overall chamber height required to obtain touchdown similar to experiment was found to be at H = 49.5. The proposition of increasing the chamber height alone to reach touchdown state would make the analysis computationally intensive and potentially infeasible. For further analysis, 3D model, brought in action, revealed touchdown to occur at similar parameters with similar trend of pressure plot as the 2D model.

Sumit Verma, R. Panneer Selvam

### Numerical Investigation of Blood Flow in Idealized Abdominal Aorta with Renal Bifurcation Using Fluid–Structure Interaction

Numerical simulations investigating the mechanics of blood flow through elastic arteries have demonstrated the significance of haemodynamics study in the cardiovascular flows. The present study investigates the flow behavior in an idealistic abdominal aorta with renal bifurcation obtained from the computed tomography (CT) image data. Geometric model is generated using ANSYS design modeler and numerical analysis is investigated using FSI technique in ANSYS-17. The fluid domain representing the blood flow is Newtonian, incompressible, and homogenous, while the solid domain representing the arterial wall is linearly elastic. The time varying two-way interacting sequentially coupled field simulation is carried out using FSI solver. The present study investigates the haemodynamic parameters to understand the influence of flow changes at the renal bifurcation region. The flow behavior is compared at rest and exercise conditions throughout pulsatile flow and the considerable changes are observed through the results obtained. This fundamental study shall be useful to understand the flow behavior in patient-specific cases.

S. M. Abdul Khader, B. Raghuvir Pai, D. Srikanth Rao, K. Prakashini

### Simulation of MD Using OpenMP and OpenMP–SIMD

MD is used to understand the temperature and pressure dependencies of dynamical concept in liquids, solids, and liquid–solid interfaces. It is a computer simulation method to visualize the behavior of atoms and molecules. MD simulation techniques are also well defined for understanding surface phenomena, as they give a qualitative understanding of surface structure and dynamics of particles filled in a box. Our work uses MD methods to better comprehend surface pressure and calculation of time they take to interact with one another. We aim to use OpenMP and OpenMP + SIMD directives in our code to reduce time complexities. The OpenMP directive is applied to a loop to indicate such that multiple iterations of the loop can be executed at the same time by using SIMD instructs. Our studies have indicated that using SIMD directives in OpenMP tend to yield faster speedups. According to our data for the given algorithm for a maximum of 800 particles, a speedup of 1.27 was achieved for OpenMP + SIMD against OpenMP alone. We will implement SIMD parallelization to Verlet’s algorithm used in MD calculations, such as updation and computation of position, velocity and acceleration. We also intend to bring out the percentage of error in total energy calculated in our work to convey the accuracy of the methods.

Naman Khurpia, Arunim Roy, Saransh Goyal, J. Saira Banu

### Design Fabrication and Testing of a Double-Pass Solar Air Heater

In this paper, experimental investigations on a double-pass packed bed solar air heater are presented. Improvement in thermal performance of the air heater with mild steel chips as the packed bed material is found at different mass flow rates of air. Experiments are carried out at different mass flow rates of air in a range of 0.036–0.0625 kg/s. The maximum air temperature at SAH outlet with and without packed bed is 64 °C and 59 °C, respectively, at a mass flow rate of 0.047 kg/s. The thermal efficiency of double-pass SAH is found to be improved by 20.4% over conventional SAH without a packed bed.

I. V. Kumar, M. Mohan Jagadeesh Kumar

### Design Fabrication and Testing of a Heat Exchanger in a Solar Thermal Energy Conversion System

In this document, a shell and tube heat exchanger (STHE) is intended, produced, and experimentally tested for distinct mass flow rates of both warm and cold fluids in a solar thermal energy conversion system (STECS). STHE’s performance is discovered by experiments conducted over 25 days at distinct combinations of heat and cold fluid mass flow rates. The studies are initially carried out to maintain the flow rate of warm fluid mass at a speed of 60 kg/h and the flow rate of cold fluid mass between 120 and 300 kg/h. Further studies with a set cold fluid flow rate of 60 kg/h are proceeded, and the warm fluid flow rate varies between 120 and 300 kg/h. The average maximum temperature of hot fluid by the use of evacuated tube solar collector (ETSC) is found to be 80 °C. Experimental results show that the STHE has a maximum effectiveness of 0.74 when the mass flow rate of warm and cold fluids is 60 and 300 kg/h, respectively. The effectiveness also averages up to 0.6508 with cold and hot fluids mass flow rates of 60 and 300 kg/h.

Vikash Gora, M. Mohan Jagadeesh Kumar

### Unsteady Casson MHD Flow Due to Shrinking Surface with Suction and Dissipation

The present paper is on 2D Casson magnetohydrodynamic flow through exponentially shrinking surface. The set of nonlinear PDEs are established into ODEs by using R-K scheme connected by shooting methodology. Some of the physical quantities are implemented to demonstrate the effects of exponential, Eckert number, Casson and radiation parameters on temperature and velocity distributions. The constraint of Eckert numbers decelerates the rate of heat transfer in both $$\Pr = 2$$ and $$\Pr = 9$$ cases.

P. Durga Prasad, R. Sivaraj, B. Madhusudhana Rao, C. S. K. Raju, K. Venkateswara Raju, S. V. K. Varma

### MHD Casson Fluid Flow Past a Stretching Sheet with Convective Boundary and Heat Source

In this manuscript, we investigate an electrically conducting, laminar and an incompressible 2D (two-dimensional) Casson fluid above a nonlinear permeable sheet in the occurrence of Newtonian heating and heat source. The nonlinear coupled arrangement of typical differential conditions are acquired through appropriate changes and after that figured by utilizing R-K method including shooting technique. The behaviour of dimensionless parameters is presented graphically and discussed velocity and temperature distributions along with friction aspect coefficient and rate of heat transfer concerning Nusselt number. It is discovered that the Casson and Newtonian warming parameters increase the grinding factor coefficient and heat transfer rates.

K. Venkateswara Raju, P. Durga Prasad, M. C. Raju, R. Sivaraj

### Physical Significance of Rotation and Hall Current Effects on Hemodynamic Physiological Jeffery Fluid with Porous Medium Through a Tapered Channel

The aim of this research is to analyze the rotation and hall current effects on hemodynamic physiological Jeffery fluid through a tapered channel with porous medium. The pressure rise, velocity, pressure gradient, and frictional force are discussed analytically. An influence of varied governing parameters was illustrated diagrammatically with a set of figures. We identified that as we increase the rotation parameters, the velocity decreases. The velocity of the fluid enhances when we increase hall current parameter. We observed an increase in pumping rate in the retrograde pumping zone, the peristaltic pumping zone, the free pumping zone, and the co-pumping zone, pumping rate decreases when $$\overline{Q} > 3$$ by an increase in rotation parameter.

R. Sivaiah, S. Ravikumar, R. Hemadri Reddy, J. Suresh Goud, R. Saravana

### Comparative Aerodynamics Analysis of Maruti Suzuki Alto Models

The automotive industry is now focusing on providing well-balanced commercial vehicle models based on performance and efficiency. The pressure from the environmental impacts and the increase in oil prices have led to the increased economy from both engines as well as outer car body over time. The aerodynamics of a vehicle was not substantial until the 1960s when the models were noisy and less efficient. However, with the arrival and advancement of fast-moving vehicles, it was highly essential to protect the vehicle from the effects of air drag and lift forces, which may cause loss of control at high speeds. This paper shows a comparative CFD analysis on Maruti Suzuki Alto models by highlighting the improvements done on aerodynamics in 2005 and 2012 models, respectively. The Alto is chosen as the subject of study in order to demonstrate the extent to which the fluid dynamic forces affect a commercial vehicle. The paper provides both 2D and 3D analysis on cruising conditions simulated on ANSYS® software and a qualitative study on the importance and significance of streamlining a vehicle in the present time.

M. K. Pradhan, Jai Kumar Verma, Suyash Kumar Jain, Kunal, Himal Pariyar, Raja Das

### Effect of Hydrostatic Stress and Piezoelasticity in a Thermopiezoelectric Layer Resting on Gravitating Half Space with Slip Interface

In this paper, an analytical model is developed to study the influence of initial hydrostatic stress and piezoelasticity on elastic waves in a thermopiezoelectric layer embedded on a gravitating half space with slip interface. The thermopiezoelectric layer considered for this study is hexagonal (6 mm) material. The problem is described using equations of linear elasticity with initial hydrostatic stress and piezothermoelastic inclusions. Displacement functions in terms of velocity potential are introduced to separate the motion’s equations, heat and electric conduction equations. The frequency equations are obtained by stress-free, insulated thermal and electrically shorted boundary conditions at the gravitating half space. The numerical computation is carried out for the PZT-4A material. The obtained results are presented graphically to show the effect of piezoelastic coupling and hydrostatic stress on the elastic waves.

R. Selvamani, R. Panneer Selvam

### Effect of Viscous Dissipation of Laminar Flow over a Flat Plate with Variable Properties

The current study focused on forced convection water boundary layer flow on permeable diverging channel for variable physical properties of fluid. The formation of coupled nonlinear partial differential equations is expressed in terms of non-dimensional quantity using similarity transformation. The solution of non-dimensional differential equation obtained by numerical finite difference scheme with combination of quasi-linearization technique. It is found that the Eckert number is significant in the boundary layer region in laminar flow, and also, the effects of physical parameters are investigated numerically and shown graphically.

A. K. Singh, G. Iyyappan, B. Jaganathan

### Darcy–Bénard Convection with Internal Heating and a Thermal Nonequilibrium—A Numerical Study

The impact of local thermal nonequilibrium (LTNE) in the presence of a uniform internal heating in both the fluid and solid phases of the porous medium on the onset of Darcy–Bénard convection is investigated. Emphasis is laid on LTNE effect on the steady-state heat conduction in analyzing the onset criterion. The Galerkin method is used to carry out the parametric study on the instability characteristics of the system by numerically computing the critical stability parameters. The presence of LTNE effect on the steady-state heat conduction is found to advance the onset in comparison with its absence and also to increase the dimension of convection cells. The exiting results are obtained as a particular case from the present study.

C. Hemanthkumar, I. S. Shivakumara, B. Rushikumar

### Stability of Natural Convection in a Vertical Anisotropic Porous Channel with Oblique Principal Axes Under Thermal Nonequilibrium Conditions

The impact of anisotropies in the permeability with slanted principal axes and thermal conductivity of fluid as well as solid phases on the stability properties of convection in a vertical porous layer is deliberated under the contemplation of thermal nonequilibrium. The classical energy analysis is observed to be insufficient in dealing with the stability analysis because of the tilting of the main principal axes of permeability with the gravity vector. Accordingly, the stability eigenvalue problem is solved numerically. It is found that the system is always stable for all infinitesimal disturbances irrespective of the values of physical parameters considered.

S. B. Naveen, B. M. Shankar, I. S. Shivakumara

### Application of Grey Theory and Fuzzy Logic to Optimize Machining Parameters of Zircon Sand Reinforced Aluminum Composites

The increasing demand for lightweight materials in various engineering and structural applications led to the introduction of aluminum matrix composites (AMC). In this work, a novel zircon sand (ZrSiO4)-reinforced aluminum (grade-LM25) matrix composites were produced using stir casting method, and experimental investigation on machinability based on 18 orthogonal array of mixed level design is carried out formulated by Taguchi. Machining conditions (Dry/MQL), cutting speed (CS), depth of cut (DoC), feed rate (FR) and zircon sand reinforcement are varied in the experiments, and output responses like resultant cutting force (Fr), surface roughness (Ra) and tool wear (TW) were measured. Fuzzy logic (FL), a soft computing technique coupled with one of a multi-objective optimization technique, grey relational analysis (GRA) is implemented to find the optimal cutting parameters. The significant factors are analyzed using ANOVA. The optimum machining levels obtained are MQL cutting environment with a cutting speed of 200 m/min, feed rate of 0.06 mm/rev, depth of cut of 1 mm and 10% zircon sand particle reinforcement.

M. Vignesh, R. Ramanujam, G. Rajyalakshmi, Sayantan Bhattacharya

### Performance and Emission Characteristics of Compressed Ignition Engine by Using Non-edible Coconut Biodiesel

Biodiesel is an alternative to diesel made from animal fats or vegetable oils. In this study, fatty acid methyl ester extracted from coconut oil was used as a substitute to diesel for evaluation of properties, performance and exhaust emissions of a one-cylinder high-speed diesel engine. The operating performance and the emission characteristics were compared. The engine did not exhibit any starting difficulties although coconut oil utilization has slightly undesirable effects on engine performance of brake power output and specific fuel consumption; it can be utilized as fall back fuel in diesel engines, by this way CO and NOx emissions can be reduced.

Kanikicharla Jaya Sudheer Kumar, Arekanti Naga Raju

### Bernstein Polynomial Collocation Method for Acceleration Motion of a Vertically Falling Non-spherical Particle

This work deals with the falling of non-spherical particle in incompressible Newtonian media. The Bernstein polynomial collocation method (BPCM) is used to find out velocity and acceleration, and obtained results by BPCM are compared with variational iteration method (VIM), differential transform method (DTM), and the fourth-order Runge–Kutta method (RK-4). It is shown that this method gives a more accurate result when compared to the differential transform method, and the solution converges fast in comparison with VIM. Moreover, the use of BPCM is found to be simple, flexible, efficient, and computationally elegant.

Sudhir Singh, K. Murugesan

### Overlapping Multi-domain Bivariate Spectral Method for Systems of Nonlinear PDEs with Fluid Mechanics Applications

An efficient overlapping multi-domain bivariate spectral quasilinearization method (OMD-BSQLM) is introduced for non-similar boundary layer equations arising in fluid mechanics. Previously, the multi-domain approach has been applied to either space or time interval but not both. The new method applies the multi-domain technique in both space and time interval. The time interval is decomposed into non-overlapping sub-intervals, and the space interval is split into overlapping sub-domains. Numerical experiments are carried out to highlight the accuracy and efficiency of the method. An analysis of the convergence and accuracy of the OMD-BSQLM is given using error norms and residual errors. The series solutions are used to validate the accuracy of the OMD-BSQLM results. The new method converges rapidly and gives accurate results after a few iterations and using a few grid points. Moreover, the accuracy does not worsen when a large time domain is considered.

Musawenkhosi Mkhatshwa, Sandile Motsa, Precious Sibanda

### Electromagnetohydrodynamic Flow of Blood on Unsteady Convective Diffusion of Solute in a Capillary Bounded by Porous Beds

The mathematical model, presented here, is developed to study the influence of electromagnetohydrodynamic (EMHD) flow of blood on generalized dispersion of an unsteady convective diffusion in a channel bounded by porous beds. Impact of electric and magnetic field, arising as a body couple in the governing equations, is shown to increase the axis dispersion coefficient. The effect of various physical parameters such as Hartmann number, electric number, porous parameter and couple stress parameter on the velocity, dispersion coefficient and mean concentration is discussed in detail with the help of graphs.

Nirmala P. Ratchagar, R. VijayaKumar

### Chemical Reaction and Thermophoresis Effects on MHD Mixed Convection Flow Over an Inclined Porous Plate with Variable Suction

The current work describes the chemical reaction and thermophoresis impacts on MHD flow past an inclined plate at an angle $$\alpha$$ within the presence of variable suction and uniform porous medium. Perturbation technique is used to determine the solution of non-dimensional equations, and the obtained results are discussed with the help of graphs on physical quantities for the consequences of the pertinent parameters.

D. Harish Babu, S. Samantha Kumari, P. V. Satya Narayana

### The Characteristics of Heat and Mass Transfer on MHD Fluid Flow over a Moving Melting Surface

The magneto-hydrodynamics (MHD) fluid flow above a moving melting surface in the existence of sticky intemperance under heat in addition mass transfer characteristics are examined theoretically and to be furnished in this article. The flow equivalent equations are solved by means of R-K method of 4th order. The impact of notable parameters on velocity, concentration, and temperature is deliberated through graphs. A comparison is made with the previous literature to validate the method and found good agreement. Concentration of the fluid decreases up to η = 2 and it increases for η > 2 with increasing values of Sc and Sherwood number increases for raising Sc values.

S. Harinath Reddy, D. Harish Babu, K. Kumaraswamy Naidu, M. C. Raju, P. V. Satya Narayana

### Casson Nanoliquid Flow Due to a Nonlinear Stretched Sheet with Convective Conditions

This work is explored to test the influence of convective boundary conditions on magnetohydrodynamic three-dimensional Casson nanoliquid motion generated by a nonlinear stretched sheet. Using suitable functions, the flow governing PDEs are changed into a set of ODEs. The resulting set of coupled nonlinear equations is solved computationally with the help of BVP-4 MATLAB software. The characteristics of different flow parameters such as Biot number, thermophoresis parameter, magnetic field parameter, non-Newtonian parameters on the flow, energy, and species concentration are discussed and displayed pictorially. The results reviled that the both energy and species concentration distributions rise with increasing Biot number.

S. Samantha Kumari, G. Sankara Sekhar Raju

### Effects of Aligned Magnetic Field and Slip on Peristaltic Flow of a Williamson Fluid in a Flexible Conduit with Porous Medium

In this paper, we have studied the joint effects of slip and aligned magnetic field on the peristaltic transport of a Williamson fluid in an elastic conduit with porous medium. The basic equations of Williamson fluid model in Cartesian coordinate system are built and simplified by using small Reynolds number and long wave length approximations. The simplified nonlinear equations are solved by adapting the perturbation method. The stream function and the axial velocity expressions are obtained. The impacts of important physical parameters on the flow are shown in graphs and discussed in detail.

G. Sucharitha, G. Yasodhara, S. Sreenadh, P. Lakshminarayana

### Influence of Electromagnetic Force on the Blood Flow in an Asymmetric Channel with Heat Dissipation

The present article examines the magnetohydrodynamic blood flow in an asymmetric channel with heat dissipation. The exact solutions for the velocity, pressure gradient and temperature are provided for both the cases such as the presence and absence of electromagnetic force under the long wavelength and low Reynolds number assumptions. The pressure rise expression has been computed using numerical integration. The graphical results have been presented to analyze the physical behavior of various physical parameters of interest. The present study reveals that the higher values of pressure gradient and axial velocity appears in the presence of electromagnetic force as compared with an absence of electromagnetic force. This result highlights that electromagnetic force is useful for strengthening the pressure gradient and velocity of fluid. The physiologists use the concept of electromagnetic or magnetic forces to maintain the pressure gradient levels in patients. The role of the heat exchange coefficient may control body temperature.

R. Latha, B. Rushi Kumar

### Numerical Investigation of Non-Fourier Flux Theory with Chemical Action on Maxwell Radiating Nanoliquid: A Biomedical Application

In the modern critique, we deliberated a theoretical model of blood with carbon nanotubes (CNT’s)—ejected in a Maxwell fluid with dissipative nanoparticles through binary chemical reaction lying on a stretching sheet by means of aligned field of magnetism. A customized Arrhenius function is imposed for energy activation. A non-linear radiation and a heat source/sink which is not uniform are incorporated in the energy equation which named as Cattaneo–Christov model of heat diffusion. Convective slip and suction are also added. Single and multiple walled nanotubes of carbon are employed with human blood as working liquid. A non-linear system is obtained for the considered problem, and an attempt is made by using Runge–Kutta fourth order through shooting (RK4S) method—bvp4c codes in MATLAB. The results are discussed and plotted in graphs for embedded parameters of concern. Higher activation energy improves the concentration, and a rise in chemical reaction rate constant raises Sherwood number. This study is thoughtful for medical surgeons during surgery in regulating the blood flow.

Suneetha Sangapatnam, Subbarayudu Ketineni, Ali J. Chamkha, Bala Anki Reddy Polu

### Mechanics of Multifunctional Composites and Their Applications: A Review of Challenges and Emerging Trends

Multifunctional structural materials are designed to perform more than one function, apart from their inherent load bearing capabilities. Therefore, multifunctional materials are composite in nature and are in great demand in various applications. Several researchers have been working on enhancing designs of multifunctional composite structures. Fabrication of multifunctional composite materials is a confronting task due to the involved critical structures. The new generation of multifunctional composite materials will consist of not only interacting components and micro-structural morphologies but also materials that respond differently under combined external influence. Therefore, the material selection and hence the structural design of multifunctional systems that can efficiently handle multiple fields such as mechanical, thermal, electromagnetic fields, to name a few, is a challenging task. An attempt has been made here to present a review of the latest technologies in the field of multifunctional structures. The main aim of the present review is on the study of modified constitutive laws for various scenarios and the relevant applications in fields like aerospace, automotive, construction, energy, clean water generation, to name few.

V. Sowjanya, B. Rammohan, P. R. Budarapu

### Oscillatory Darcy-Bénard-Poiseuille Mixed Convection in An Oldroyd-B Fluid-Saturated Porous Layer

The combined effect of horizontal pressure gradient and the thermal buoyancy caused by gravity forces on the onset of convective instability in a layer of an Oldroyd-B fluid-saturated porous medium is investigated. The stability equations are found to be with complex coefficients, and the ensued generalized eigenvalue problem is solved numerically by utilizing the Galerkin method with the aid of QZ algorithm as well as analytically using a single-term Galerkin approach. The instability is instilled as oscillatory under certain conditions. The effect of constant horizontal pressure gradient is to advance the onset of oscillatory convection and also to increase the range of values of the strain retardation parameter within which the oscillatory convection is preferred. Besides, the critical frequency of oscillations is suppressed.

G. Pallavi, C. Hemanthkumar, I. S. Shivakumara, B. Rushikumar

### Inertia Effects in the Planar Squeeze Flow of a Bingham Fluid: A Matched Asymptotics Analysis

The effects of inertia on the squeeze flow of a Bingham fluid between two approaching parallel plates with a constant squeeze velocity is investigated using matched asymptotic expansions. This analysis is an extension to the prior study of Muravleva (2015), who has investigated the planar squeeze flow of a Bingham fluid in the absence of inertia. In the present study, the expressions for the shear stress field, velocity, pressure field and squeeze force are derived. The combined effects of the fluid inertia and yield stress on the pressure field and squeeze force are investigated. We found that the pressure and eventually squeeze force increases with increase in Reynolds number. The squeeze force decreases with an increase in the value of the gap aspect ratio.

Pavan Kumar Singeetham, Vishwanath Kadaba Puttanna

### The Stationary Investigation on Multi-server Fluid Queueing Model with Unreliable Server

We consider multi-server fluid queueing system including working vacation and with server breakdown. A steady-state distribution of the fluid buffer queueing distance is calculated using matrix geometric solution approach. We calculate differential equations which are satisfied by steady-state joint distribution of the function of the fluid flow.

M. Seenivasan, K. Pattabiraman, M. Indumathi

### Dynamical Properties and Synchronization Between Two Chaotic Blood Flow Models

Human heart is a complex system. It has many interacting subunits to make the whole unit complex. It has also been noticed that the dynamics in blood flow changes from laminar to turbulent flows and that can be the origin of chaos. In this paper, we discuss a coronary artery (CA) model which has a rich chaotic dynamics. We discuss the dynamical properties using bifurcation and Lyapunov exponents. We design a synchronization scheme to synchronize the dynamics of flow in the CA model. The results are effective in terms of biomathematical applications.

N. A. A. Fataf, N. A. L. Aladdin, A. S. Normurniyati

### Blasius and Sakiadis Unsteady Flow of Chemically Reacted MHD Williamson Fluid with Variable Conductivity: A Comparative Study

The present work reports a study two-dimensional (2D) Blasius and Sakiadis an unsteady magnetohydrodynamic (MHD) radiated Williamson flow with variable conductivity of a chemically reacting fluid is considered. An approximate transformation was developed to transform PDEs into nonlinear ODEs. To current numerical calculation shooting technique is implemented. The computational results of the Blasius and Sakiadis flow on concentration, temperature and velocity distributions for some physical quantities are presented graphically and in tabular form.

Narsu Siva Kumar, B. Rushi Kumar

### Computational Analysis of Conjugate Buoyant Convective Transport in an Annulus

In the present work, the convective flow and thermal pattern, associated heat transport rates of buoyant convection in an annular geometry is theoretically analyzed. The inner cylindrical wall has finite thickness and is kept at high temperature, while the outer cylindrical wall is held at low temperature. The vorticity-stream function form of model equations are solved using FDM based on ADI and SLOR techniques. The numerical simulations for various parameters are presented. In particular, this analysis focused on the effects of conjugate heat transport characteristics.

S. Kiran, N. Keerthi Reddy, M. Sankar, Younghae Do

### Radiation and Heat Generation Effects on Couple Stress Fluid Through Expanding Channel

The problem of magnetohydrodynamics (MHD) radiating flow of couple stress fluid through a porous channel is studied. Fluid is injected with different injection velocities by which the flow is generated between two parallel porous walls. The equations that govern flow are numerically solved by method of quasilinearization. Flow physical properties corresponding to various physical parameters are addressed through graphs.

Odelu Ojjela, N. Naresh Kumar, D. R. V. S. R. K. Sastry

### Heat Source Location Effects on Buoyant Convection of Nanofluids in an Annulus

In this paper, the impacts of the location of a thermal source on buoyant convection of nanofluids in an annular region are analyzed numerically through the finite volume technique. Five different thermal source positions along the inner cylinder of the annulus have been analyzed. The prime objective is to identify the optimal position of the source to maximize or minimize the thermal transport at different values of Ra and diverse volume fractions of the nanoparticle ranging from 0 to 10%. The location of the thermal source has a profound impact on the flow and temperature patterns as well as thermal transfer from the discrete source to the nanofluid. Further, the volume fraction of nanoparticles also controls the heat transport in the annular geometry.

F. Mebarek-Oudina, N. Keerthi Reddy, M. Sankar

### Analytical Approach for Mixed Convective Flow in Presence of Casson Fluid in a Porous Channel

An analytical approach have been carried to study the mixed convective flow in presence of Casson fluid in a porous channel with an external constraint of magnetic field applied uniformly to the physical model. Perturbation technique has been implemented to find the characteristics of non-linear coupled partial differential equations of concentration, temperature and velocity. The pictorial representation of the effect of physical parameters such as Reynolds number R, Hartman number M2, Casson parameter β, buoyancy parameter λ, chemical reaction rate $$\gamma$$ , concentration buoyancy parameter N, Prandtl number Pr, Schmidt number Sc on concentration, temperature and velocity has been studied. As the variation of non-dimensional parameters make an important role in studying the changes on concentration, temperature and velocity. The analysis of the solution is also compared with the earlier work, and for a particular case, it has been found to be good agreement.

B. V. Shilpa, D. V. Chandrashekhar, P. A. Dinesh, A. T. Eswara

### D-Shaped Biosensor with MoS2 as a Sensing Layer Using a Photonic-Crystal Fiber

We design a D-shaped photonic-crystal fiber (PCF) based on surface plasmon resonance (SPR) for the detection of cancer cells. It is coated with layers of gold (Au) and molybdenum disulfide (MoS2). Au layer is used to accurately determine the spectral sensitivity in the visible region. The analyte is placed over MoS2 layer. The sensitivity of the sensor is enhanced with the help of MoS2. The designed sensor is highly suitable for detecting cancer cells having refractive indices 1.45 and 1.46. The proposed sensor exhibits a maximum sensitivity of 3000 nm/RIU.

Melwin Gnanasekaran, Senthilnathan Krishnamoorthy

### Surface Plasmon Resonance-Based Photonic Crystal Fiber Sensor with Selective Analyte Channels and Graphene-Indium Tin Oxide Deposited Core

We design a refractive index (RI) based triple core photonic crystal fiber sensor, which works on the principle of surface plasmon resonance. The analyte to be sensed is placed inside all the three cores. The middle core is surrounded by a layer of graphene, followed by a layer of Indium tin oxide (ITO). ITO is used as the bio-sensing layer for operating in the infrared region. The graphene layer is used to enhance the sensitivity of the proposed sensor. Numerical results corroborate that the proposed sensor exhibits a maximum sensitivity of 2000 nm/RIU when refractive index of the analyte, na is increased from 1.44 to 1.48.

Nivedha Sambathu, Senthilnathan Krishnamoorthy

### Designing a High Sensitivity Dual Steering-Wheel Micro-structured Gas Sensor in THz Region

In this paper, we intend to design a novel dual steering-wheel micro-structured optical fiber (DSW-MOF)-based evanescent-field sensor. The proposed dual steering-wheel structure consists of circular core and noncircular cladding region. By employing full-vectorial finite element method (FEM), the relative sensitivities of the gas sensor are found to be 97 and 92% for incident frequencies of 0.5 and 1 THz, respectively. The proposed sensor exhibits a low loss and a high sensitivity, and hence, it would highly be appropriate for identifying different types of chemical and biological gasses.

Ramachandran Arumugam, Ramesh Babu Padmanaban, Senthilnathan Krishnamoorthy

### Experimental and Mathematical Analysis of Performance Characteristics of Neem Blended Biodiesel Run Diesel Engine

The paper focuses on the mathematical validation of experimental performance estimates of Neem-derived biofuels mixed with diesel fuel in a proportion of 10%, as an alternative to conventional fossil fuels as a working substance in a single-cylinder, four-stroke Kirloskar AV I diesel engine with mechanical load. Biodiesel performance is evaluated in terms of braking power and mechanical efficiency at compression ratios 12:1, 15:1, and 17:1. The methodology is to find the best fit curve using nonlinear multivariate analysis that predicts the nature of the change in the corresponding output parameter of the diesel engine. The input parameters dynamic viscosity, load, CR and fuel consumption time of 10 cm3 were taken into account in the calculation of BP and mechanical efficiency for NB. The output performance parameters, namely BP and mechanical efficiency, have unique mathematical empirical expression and found strong correlation between results of experimental and mathematical modeling with the R2 values 0.9555, 0.9845, and 0.9829 for BP and 0.9963, 0.9882, and 0.9993 for mechanical efficiency at CR 12:1, 15:1, and 17:1, respectively. It is felt that the prediction of the mathematical model and the experimental and theoretical results available are closely synchronized. Wolfram Mathematica 9 was used as input for model programming.

S. Rajeesh, S. V. Prakash, P. A. Dinesh

### Characteristic Study of Coriolis Force on Free Convection in a Finite Geometry with Isotropic and Anisotropic Porous Media

Work carried out in this paper deals with classic Rayleigh–Bѐnard problem for an unsteady, laminar, viscous incompressible fluid of a horizontal layer heated from below which is extended to the three-dimensional convection in a rectangular box with anisotropic and isotropic porous media rotating with constant angular velocity that is investigated. For the given physical system, seven governing PDEs are transformed to system of non-dimensional ODEs using similarity transformation. The investigation demands to apply Fourier series method to study the characteristic of velocity and temperature for the effect of Taylor number, Rayleigh number and Prandtl number for both isotropic and anisotropic cases. The results of the stream function and isotherms on various parameters have been discussed and found to be good agreement for the physical system.

Sudhir Patel, P. A. Dinesh, S. P. Suma, N. L. Ramesh

### Effects of Forchheimer, MHD and Radiation Absorption for Chemically Reacting Unsteady Dusty Viscoelastic Fluid Couette Flow in an Irregular Channel

In this work, a study which contributes toward the combined effects of Forchheimer, MHD, and radiation absorption for a laminar two-dimensional chemically reacting unsteady dusty viscoelastic fluid in an irregular channel is considered. The physical model demands nonlinear coupled partial differential equations under the wavy channel conditions. Computational results are obtained to understand the characteristics of velocity, temperature, and concentration for various physical parameters involved in the model using a novel analytical perturbation method with combined Soret and Forchheimer number. Obtained results are well matched with the physical model and found to be a good agreement with the earlier works for a particular case.

P. A. Dinesh, A. S. Vasudevamurthy, M. Uma

### Radiation Absorption on MHD Convective Flow of Nanofluids over a Moving Vertical Porous Plate

We discussed the unsteady MHD free convective flow over an infinite moving vertical porous plate in nanofluids taking radiation absorption into account. The exact solutions for governing equations are obtained using Laplace transform technique. The nanofluid concentration, temperature, velocity, the Sherwood number, Nusselt number, and the shear stresses at the plate are found analytically and discussed graphically for the pertinent parameters.

M. Veera Krishna, B. V. Swarnalathamma, J. Prakash

### Hall Effects on MHD Free Convective Flow Through Porous Medium in Vertical Channel

We have considered the steady fully developed MHD free convection flow through porous medium between two infinite vertical parallel plates due to asymmetric heating of plates taking Hall current into account. Effects of velocity slip and temperature jump have been considered on the micro-channel surfaces and analytical solutions have been obtained for momentum and energy equations under relevant boundary conditions. The influence of governing parameters on flow formation is discussed with the aid of graphs. The significant result from the study is that, increase in the value of rarefaction parameter leads to enhancement in volume flow rate. Furthermore, it is evident that volume flow rate is found to be increasing function of Hall current parameter. The impact of the fluid wall interaction parameter is found to enhance the primary and secondary velocity profile.

B. V. Swarnalathamma, M. Veera Krishna, J. Prakash