Proceedings of the 1st International Conference on Advances in Aerospace and Navigation Systems - 2024

Analysing the two-phase flow behaviour of cryogenic propellants like LH2-VH2 and the accompanying flow regime utilizing volume fraction is made easier by the current analysis. Additionally, two phases of liquid hydrogen (LH2) in different inlet velocities and temperatures have been described in the current work. With the aid of the commercial CFD program Ansys Fluent, a two-dimensional computer model of a cryogenic feed line, has been created for the present study. To characterize the two-phase flow of LH2 and to accurately estimate hydrodynamic and thermodynamic properties under various situations, the volume of fluid (VOF) approach based on an Eulerian flow scheme incorporated with an energy equation is used. These models have been validated with experimental data, and the trend of volume fraction captured matches the computational result. The flow visualization and the volume fraction has evaluated along with bulk mean temperature (Tb) and velocity analysis. Therefore, the current methodology may be used to estimate the flow shape and phase distribution at different initial conditions.

This study focuses on the development of a computational framework for simulating ice accretion on three-dimensional (3D) bodies, using the open-source Computational Fluid Dynamics (CFD) software OpenFOAM. The research addresses the complex phenomena of ice formation and accumulation on 3D geometries, which are more challenging to model than traditional two-dimensional (2D) airfoils due to the additional interactions involved in three-dimensional flows, as well as the requirement for more detailed mesh and extended simulation times. The framework incorporates an Eulerian-based droplet impingement code to calculate the collection efficiency of water droplets in airflows around 3D models and uses the finite-volume method (FVM) to solve compressible Navier–Stokes equations alongside shallow water-based droplet equations. A partial differential equation (PDE)-based ice accretion solver predicts ice formation on initially clean geometries. Validation of the framework occurs in three stages: air solver, droplet solver, and ice solver, using experimental data from Bidwell et al. The air solver validation includes comparisons of pressure distribution and heat transfer coefficients around a sphere, showing strong agreement with experimental data. The droplet solver validation matches predicted collection efficiency with experimental results, demonstrating accurate droplet behavior modeling. The ice solver validation compares predicted ice accretion patterns with experimental observations, confirming the solver’s ability to replicate real-world ice formation. The detailed mesh structure, with fine grids near walls and high-resolution surface meshes, ensures accurate simulation of aerodynamic and thermal phenomena. This work significantly advances the understanding and prediction of ice accretion phenomena, essential for enhancing aircraft safety and performance in icing conditions.

Analysing the multi-phase flow behaviour of low-altitude unmanned aerial vehicles (UAVs) operating in proximity to water surfaces can provide valuable data for optimising the design and operational parameters. This study presents a comprehensive numerical analysis of the flow parameters of a fuselage equipped with a propeller operating near a water surface. The investigation focuses on the effects of varying the height-to-radius ratio (h/R) of the fuselage from the water surface, with values set at 1, 0.6, and 0.3. With the assistance of the CFD analysis, a two-dimensional computer model of a fuselage with a propeller has been created for the present study. To characterise the flow interaction of the two phases and to accurately estimate hydrodynamic and turbulence properties under various situations, the volume of fluid (VOF) approach based on an Eulerian flow scheme is used. The turbulence flow visualisation and flow parameters such as velocity, pressure, and volume of fluid (VOF) have been evaluated along with the lift coefficient (Cl), drag coefficient (Cd), and pressure coefficient (Cp) around the fuselage. The results reveal significant insights into the interaction between the propeller-induced flow and the water surface, highlighting critical changes in aerodynamic performance as the height varies.

In this study, a velocity measuring instrument has been designed to measure velocities for slow-flying unmanned aerial vehicles or VTOLs during transition; measuring such low velocities with good resolution is difficult to measure with a pitot static tube and electronic pressure sensors used with flight controllers. This instrument described in this study uses a curved surface for accelerating the flow, resulting in a higher difference in pressure compared to the conventional pitot static tube. These instruments can also be used in drones and flapping wings UAVs, which fly at a speed of around 10 m/s or less. The pressure sensors, which are currently available to measure the pressure difference with conventional pitot static tubes, are highly inaccurate in this range. These are some available venturi effects on airspeed, which are also effective and give good results at lower air speeds (10 m/s or less). However, due to their bulky size and shape, they are not easily mountable on the respective UAV and also compromise the aerodynamics of the vehicle. So, in this study, we have done a numerical investigation over varying Reynolds numbers to find the relationship between velocity and pressure difference using which the electronic air pressure sensor can be calibrated to measure the airspeed. The effects of scalability also indicate the size of the instrument can be made small enough while giving higher pressure difference at lower airspeeds.

This paper presents the design and development of a novel hypersonic flight vehicle capable of operating efficiently across subsonic, supersonic, and hypersonic speed regimes. The vehicle features a wedge-shaped aerofoil optimized for high-speed performance. Key aerodynamic parameters, including lift force, drag force, and velocity variation, are analyzed to assess the design efficiency. Computational flow analysis/CFD simulations are conducted using the finite volume method (FVM) with cuboidal mesh elements to accurately determine these parameters. The geometric modelling of the aircraft is done using Fusion 360 and OpenVSP, while the flow analysis is performed using ANSYS Fluent. The results showed a lift-to-drag ratio of 7.89 at subsonic speeds, 7.65 at supersonic speeds, and significant shockwave formations at hypersonic speeds, emphasizing the need for effective thermal protection systems. These findings provide significant inputs into the aerodynamic behaviour of hypersonic flight vehicles, contributing to the advancement of high-speed aerospace engineering. The results of this research provide significant inputs into the aerodynamic behaviour of hypersonic flight vehicles, contributing to the advancement of high-speed aerospace engineering.

Drones, also referred to as unmanned aerial vehicles (UAVs), have become increasingly popular for a variety of uses, from industrial and military to recreational. One ongoing issue with drone technology is the noise produced by the propellers while in use. This study explores a novel approach to mitigate drone propeller noise by the adoption of serrated propeller designs. The main goal of this research is to examine the effectiveness of serrated propellers in reducing the acoustic footprint of drone operations without compromising performance. The propeller is fabricated using 3D advanced manufacturing techniques. The aerodynamic and acoustic characteristics of conventional and serrated propellers is analyzed using computational fluid dynamics simulations. The Ansys Fluent with RNG k-ϵ turbulence model is used to solve the mathematical equation. Experimental validation has been conducted through controlled flight tests, where drones test benches equipped with both conventional and serrated propellers. The acoustic measurements are collected to assess the impact of serrated propellers on noise levels. The different motor powers of 25, 50, and 90% were used for the simulation and experiment to analyze the characteristics of noise emission from the propeller. According to the result obtained, it shows that the noise reduction is only effective up to 50% of motor power and approximately a 5.7% decrease compared with conventional propeller.

In aviation, efficient aerodynamic performance is essential, particularly for military and commercial aircraft where reducing drag is critical. This research investigates the impact of split configurations and flow control techniques on a NACA 0012 airfoil model. Experiments and computational fluid dynamics (CFD) simulations investigate a range of split positions, ranging from 0.45 to 0.55c and 0.55c0.007. The airfoil split at 0.55c performs better than the other designs, according to the results. It delays flow separation on the airfoil surface, which greatly reduces drag and improves aerodynamic efficiency especially in comparison with configurations with splits at 0.45, 0.5, and 0.55c. In order to maximize aerodynamic performance, this study emphasizes the significance of split configuration design and the potential benefits of purposefully positioning the divide at 0.5c by aircraft designers to enhance efficiency.

The research explores the biomimetic qualities of owl wing morphology, particularly its sound-reducing and aerodynamic capabilities, in comparison with a conventional airfoil. Owl wings are known for their unique saw-tooth-like serrations along the leading edge, which play a crucial role in reducing noise by dissipating eddy flow and mitigating turbulence-induced sound. To replicate this effect, serrations were incorporated into the leading edge of a NACA 63-412 airfoil. A thorough numerical analysis was conducted on both the standard and serrated airfoils at various angles of attack (0, 3, 6, 9, and 12°), evaluating both aerodynamic and acoustic performance. The results revealed a significant reduction in sound production across different flow conditions for the serrated airfoil, underscoring the effectiveness of this biomimetic adaptation.

The study investigated the influence of fuel injection position in a supersonic reacting flow environment inside a bottom wall cavity. To understand the flow mechanics in supersonic combustion, a numerical analysis has been performed using the Reynolds-averaged Navier–Stokes (RANS) equations combined with the shear stress transport (SST) k-ω turbulence model. Shock patterns, along with pressure and temperature variations throughout the combustor, have been analyzed. The computational technique can be applied to further research as the computational findings are within a reasonable range and are corroborated by experimental evidence. Unlike the DLR scramjet, adding fuel injectors in the cavity increases wall pressure owing to the intensified shock wave production at the cavity’s edges, which in turn amplifies the total pressure loss of the combustor.

This paper attempts to computationally explore the influence of the shear layer, chemical kinetics model, and dimensionless thermal diffusivity ratio based on the Prandtl number on velocity field in a chamber-based supersonic combustor. The simulated results are benchmarked against empirical data available from open sources. An overprediction of 10% in comparison with the experimental measurement was observed for pressure in the flow direction at the fore edge of the chamber. The study of grid discrepancy using coarse, medium, and refined grids reveals that a moderate grid of about 1.2 million cells provides a good compromise, balancing accuracy, and computational cost. The shear layer, chemical kinetics model, and boundary surface Prandtl number significantly influence the pressure distribution along the surface of the chamber. For instance, the use of a Prandtl number of 1.2 on the boundary surface led to a 15% decrease in static pressure along the surface of the chamber, with a Prandtl number of 1.2 identified as optimal for satisfactory prediction of the flow field. The present study provides important inputs for the optimized design of a supersonic jet engine combustor. The computational findings are compared with relevant empirical data, and a critical evaluation is made based on the application of the CFD approach toward the simulation of supersonic jet engine combustor reactive flow fields.

Grid fins are used in missiles and rockets effectively. The main drawback of grid fin is the higher drag compared to the convention’s fins. In this study, sweptback grid fin is analyzed using CFD and compared with the basic grid fin. Computations have been carried out at supersonic Mach numbers using HiFUN CFD software. The flow field around the basic and swept grid fins are analyzed and presented. The aerodynamic characteristics of the basic grid fin are compared with experimental data to validate the HiFUN software and found the comparison is good. The aerodynamic characteristics of the swept grid fin are compared with basic configuration. The results demonstrate decreases in drag coefficients for the sweptback fin compared to the basic fin at Mach numbers 1.8, 2.5, and 3.5, spanning different angles of attacks. Furthermore, slight increase in normal force and pitching moment coefficients are observed. Overall, these findings highlight the efficacy of the sweptback fin design in improving aerodynamic performance, suggesting potential enhancements in flight stability and efficiency under supersonic conditions.

Fluid–structure interaction is the interaction between movable or deformable part with the surrounding fluid. The surrounding fluid exerts pressure on the structure, thus causing it to deform, and the deformation of the structure in turn causes changes in the fluid flow. Fluid–structure interaction analysis is very important for the design of efficient and lightweight structure of various aircrafts components especially the wings. In order to calculate the aerodynamic forces, stresses, and frequency of different modes operating on the wing, a scaled-down model of a rectangular planform wing is created and static analysis is performed. Two materials are analysed: aluminium metal matrix composite and glass fibre reinforced polymer. The coupled mode analysis is performed and compared to see how the flow pattern and structure change when the wing is regarded flexible. The coupled mode analysis includes both one-way and two-way FSI analysis. The structural and fluent findings are evaluated independently. The analytical findings are compared to determine the best of the two materials mentioned in the present work. Furthermore, for a given loading and stress level, it is found that aluminium metal matrix composite deforms the least. Moreover, when the wing is viewed as a flexible structure, its aerodynamic characteristics are shown to decrease.

A hybrid drone is a powered aircraft that obtains some of its lift as a lighter than air in airships and some from aerodynamic lift for a conventional hex copter construction. A dynastic is with a hull of helium gas as a partial lifting body, and it is typically for long endurance flights. It works by the buoyancy of a low-density gas and hex copter construction for maneuvering. The helium-assisted hybrid drone is capable to fly with minimum power consumption. The project is a hybrid drone that has the characteristics of the lighter than air system (LTAS) and drone. Combining buoyancy for less dense gases like helium with hex copter propulsion can indeed minimize power consumption and increase flight time for drones. Using helium balloon is to provide a high lifting force. This project has the high efficiency and endurance properties comparable to conventional drones. By modifying the designing, we may have better efficiency, higher payload carrying capacity, and low cost, along with better aerodynamics characteristics of the drone. The proposed drone design increased flight endurance by 25%, with a standard difference of 5%, compared to conventional multi-rotor drone on all operating conditions.

The bladeless windmill concept offers a precise remedy for the drawbacks and problems of the traditional windmill. The principle behind the bladeless windmill is the vortex shedding effect. With less moving parts, the bladeless windmill generates electricity by the piezoelectric material by the oscillations or vibrations caused by wind. The ultimate objective of the research is to design a bladeless windmill using composites material with different properties, different shapes, and different designs and to examine the flow characteristic of the operations over the design using ANSYS. With various designs of mast such as cylindrical, tapered cylinder, and hollow tapered cylinder with three different materials of E-glass, carbon fiber, and in various lengths were compared. With the results over the design, E-glass fiber with 3 m length and solid-tapered section could produce more amount of electricity.

Semi-empirical methods are often used in the preliminary design stage for quick estimation of aerodynamic coefficients for conventional ammunition. Generally, an aero-data prediction from the semi-empirical method is relatively more accurate and fast. The present work is about exploring the possibility of applying the semi-empirical method to non-conventional geometries. Aerodynamic coefficients were generated using the projectile design and analysis system (PRODAS) tool, which is a well-known semi-empirical method, and computational fluid dynamics (CFD) in the subsonic flow regime. The results from PRODAS indicated that the ammunition exhibited an aerodynamically stable geometry, indicating favorable flight characteristics. When a detailed CFD analysis was conducted using Ansys Fluent, ammunition exhibited aerodynamic instability under similar flow conditions. Therefore, this study shows that aerodynamic coefficients estimated using the CFD method for non-conventional geometry at the preliminary design stage are more precise than those estimated using the semi-empirical method and save time for later stages of design.

This article demonstrates the effect of unfolding the fins of an air delivered projectile on its stability with time. The stability margin of an air delivered projectile was studied in a 6-DoF coupled computational fluid dynamics (CFD) simulation from a wing station of an aircraft in a control volume as the fins were unfolded from their respective enclosures. The fins were fully unfolded as the projectile travelled freely under the influence of aerodynamic and gravity forces. The simulation used an inviscid regime to simplify the problem, and boundary conditions were given to imitate a specific altitude. This study has pointed out the notable changes in a critical performance factor of the store and aims to provide a better fundamental understanding of it, in this special case of tail section with unfolding fins. The static margin of the projectile is a critical aspect of the safe store separation and accuracy of the projectile, and it would greatly influence the safe separation and performance aspects of the projectile. The same study has been carried out without the presence of the wing to better understand the effect of the wing on the stability of the store. The results gave insights on how the stability of the store changes in the presence of the wing during the store separation.

The base drag is a critical component of the overall drag experienced by projectiles which arises due to the low-pressure wake formed behind the projectile as it moves through the air. Base bleed, boat tail, and other active and passive ways are utilized to decrease this component of drag and increase performance and range. This study focuses into how incorporating bleed holes of various types can affect the drag characteristics at the base, of the projectile. Computational fluid dynamics (CFD) simulations were carried out using the CFD++ solver to analyze the flow behavior and drag forces. Three parameters—holes entry and exit locations, entry angle—were methodically varied in the study to evaluate their impact on the base pressure and total drag of the projectile in supersonic flow at Mach 2. For some design iterations, where there was an appreciable amount of drag reduction at Mach 2, numerical analysis was also carried out for other Mach Nos. such as Mach 0.6, 0.8, 1, 1.2, 1.5, and 2.5. Comparison was also done on the effect of bleed holes with and without the presence of a rotating band. Through visualizations of contour plots and analysis of extracted data, it was evident that each parameter impacts the base drag in a different way and also has an effect on the near-wake flow which will be discussed in this paper. The reduction in base drag was found to be greater when the bleed holes exited through the base lip rather than into the cavity. In the subsonic regime, the base drag reduction was up to 16%, while the total drag reduction was up to 5% in the geometry with bleed holes exiting through the base lip. This underscores the importance of optimizing bleed holes design for aerodynamic efficiency in projectiles.

Kinetic Energy Projectile popularly known as Fin Stabilized Armoured Piercing Discarded Sabot (FSAPDS), damages the enemy tanks by penetrating the thick armour of the tank. FSAPDS needs to be designed to offer lower drag to keep higher momentum and required stability margin to attain an undisturbed flight to cause damage to the armour plates of main battle tanks. Therefore, aerodynamic configuration design plays a crucial role to achieve minimum drop in flight projectile velocity and to provide necessary stability margin with the help of fin stabilizers. The present study focuses on the parametric aerodynamic configuration design studies which are carried out to achieve drop in velocity less than 80 m/s during the trajectory of projectile. The aerodynamic configuration design mainly consists of parametric approach applied with the help of in-house semi-empirical code and CFD simulations. Various geometrical parameters of the nose, body and fins are varied to achieve required objective of stability margin (of the order of 3–4 Calibres) along with the criteria of minimum drop in velocity. In the present study, Computational Fluid Dynamics (CFD) simulations are carried out using MIME and CFD++ software to obtain high fidelity results. The effect of variation in geometrical parameters with help of Semi-Empirical methods and CFD are presented in the present work. The studies presented in this paper will be very beneficial and quick reference for the aerodynamic design of the kinetic energy projectile (FSAPDS).

This study employs computational fluid dynamics (CFD) to investigate the phenomenon of barrel distortion induced by solar heating. The focus is on analyzing non-uniform heating effects on the outer walls of barrel. The process involves applying a heat flux to the outer surface of the barrel over a fixed period of time to emulate solar radiation. The CFD model incorporates detailed geometry, mesh, and boundary conditions accounting for heat transfer within the barrel material and to the surrounding fluid flow. Simulation captures thermal interaction between the fluid and solid components which is crucial for accurate heat distribution predictions. Solar load model is implemented in order to simulate realistic solar heating scenarios which involves position of sun with respect to barrel. This study contributes to understanding behavior of barrels under solar heating and structural deformations induced by non-uniform thermal loads which will further help in design of thermal sleeves for barrels.

This abstract discusses the design, analysis, and construction of a vertical takeoff and landing (VTOL) RC copter (Bliamis et al. 2020). VTOL RC copters combine the benefits of helicopters and fixed-wing aircraft, offering a compact and maneuverable platform for vertical takeoff and landing. The design process involves exploring basic aerodynamic principles and control mechanisms to achieve optimal flight performance. The construction phase involves assembly, testing, and fine-tuning for reliable VTOL capabilities. These aircraft can perform autonomous flight, object tracking, and obstacle avoidance (Hadsanggeni and Nugraha 2015). Designing a VTOL RC copter presents challenges such as balancing weight and performance, addressing stability issues during transitions between vertical and horizontal flight, and transitioning from vertical takeoff to regular aircraft motion. This paper provides a comprehensive overview of the design, analysis, and construction of VTOL RC copters, covering key aspects such as rotor system, frame design, flight controller, and power system. It emphasizes the importance of analyzing and testing the design before flying the VTOL RC copter.

In order to enter orbit, a launch vehicle requires a substantial energy input, approximately 32000 kJ. Upon re-entry back into the planet’s atmosphere at hypersonic velocities, this energy is converted into kinetic energy, which results in significant aerodynamic heating due to atmospheric friction. To shield the vehicle from this heat, thermal management systems, such as insulators or cooling systems are employed. The most intense heating occurs at stagnation points, such as the nosecap and wing leading edges, necessitating meticulous thermal management system design at these points. This study focuses on thermal management of re-entry vehicle’s nosecap. A python code called USHMA was developed to estimate heat flux levels using engineering correlations. Thermal analysis was carried out to identify temperatures surpassing safe thresholds, prompting parametric studies to comprehend heat transfer mechanisms. A thermal management strategy was devised, incorporating multiple radiation shields, spacers, internal coatings, and material selection based on analysis. The design was validated ensuring the safe operation of all components.

With the increasing demand for unmanned aerial vehicles (UAVs), we propose a new method to boost the lift force of small propeller systems. By integrating windshields and brushless motors, we aim to overcome the limitations of small propellers, and enhance their efficiency and performance. Inspired by the principles of aerodynamics, we assumed that positioning a larger windshield beneath the propeller can more effectively direct the airflow, increasing lift force. Through experiments and simulations, we aimed to validate the proposed approach and its potential for improving UAV technology. This project offers a promising solution to meet the evolving needs of UAV applications.

This study conducts a simulation analysis on rocket nozzles, exploring variations in potential core length across over-expanded, under-expanded, and optimally expanded nozzles at Mach numbers ranging from 1–4, employing computational fluid dynamics (CFD) techniques. In the context of space vehicles, significant external pressure fluctuations are experienced during atmospheric propulsion system operation. These fluctuations primarily stem from turbulent mixing within the rocket exhaust flow, contributing to the acoustic field. A comparative analysis is conducted, juxtaposing simulation results with experimental data and referencing variations in potential core length documented in NASA SP8072. The findings reveal a strong correlation (87%) between properly expanded jets and experimental outcomes, indicating an increase in potential core length with rising Mach numbers. Remarkably, this study result also presents that under-expanded and over-expanded jets exhibit shorter potential core lengths compared to optimally expanded counterparts.

This study examines the significant influence of energy dynamics on axial compressor performance, particularly focusing on the axial spacing between the rotor and stator. Through numerical analysis utilizing CFD simulations with the ANSYS 19.0 R3 FLUENT software, we validate the impact of axial spacing on the performance of a single-stage compressor cascade. Our investigation specifically addresses the axial area between rotating and stationary blade rows in axial-flow compressors, emphasizing geometry and aerothermodynamic considerations. The analysis, conducted across various axial spacing (18%, 20%, 22%, and 24%), aims to optimize axial spacing for improved pressure rise and compressor cascade efficiency. Consequently, reducing the gap between the rotor and stator axial decreases compressor diffusion capacity, thereby enhancing cascade performance.

The analysis centers on deploying a lunar lander designed to achieve a safe and seamless touchdown. The mission involves several key phases: de-boosting from lunar orbit, rough braking with an 800 N main engine, precision braking, and vertical descent with 50 N altitude control thrusters. These engines are used to gradually decelerate the lander and ensure a controlled landing. A crucial aspect of the mission is selecting materials that can withstand the harsh conditions of lunar descent. The focus is on understanding how different materials affect the lander’s thermal performance and structural integrity. During descent, thruster plumes interact with the lander, influencing convective heat transfer and overall thermal dynamics. Advanced numerical simulations and rigorous material testing are used to evaluate how various materials impact the thermal protection system and structural resilience of the lander. These simulations predict heat distribution and material response under descent conditions, while testing validates these predictions by subjecting materials to simulated lunar environments. Optimizing material selection involves finding a balance between thermal insulation and mechanical strength to withstand both heat and impact forces. Design adjustments, such as incorporating effective heat shields or improved cooling systems, are made based on simulation and testing results. This research aims to enhance the lander’s durability and mission success by providing crucial insights into material performance and spacecraft design for future lunar exploration endeavors.

The topology optimization of helicopter tail booms is essential for improving structural performance and reducing weight. This research focuses on the tail boom of the Aérospatiale SA 315B Lama, known for its robust truss structure. The tail boom, connecting the cabin to the tail rotor, endures significant bending loads due to the main rotor's torque. Although modern tail booms typically have circular or elliptical cross-sections, this study adopts a trapezoidal cross-section for simplicity. The primary goal is to achieve minimum compliance under various loads while minimizing weight, using Altair’s Inspire software for simulations. The design space, modelled as a tapered trapezoidal structure, includes a circular hole at the rear for the tail rotor. Load calculations, based on main rotor torque and counteracting tail rotor thrust, were 19,129.5 N and 109,881.9 N, respectively. Simulations considered multiple load conditions: downward/upward bending, sideways bending, torsion, and tension. Results showed an I-beam structure under bending loads for maximum stiffness, emphasizing a semi-monocoque fuselage for torsional loads. Cross members were less critical than anticipated, except under sideways bending. The optimized design suggested horizontal cross members for sideways loads and a central rod-like structure for tension. Future designs might incorporate angled cross members to better address rotational loads. This study demonstrates the effectiveness of topology optimization in enhancing tail boom design, balancing structural integrity and weight efficiency.

Integration of different types of sensors for navigation is essential to incorporate the best of their features for more robust and accurate positioning. Global Positioning System (GPS) and NavIC systems provide poor vertical position accuracy. This can be improved by integrating ground-based pseudolites (Pseudo-satellites) with NavIC & GPS. Integration of GPS, NavIC & Pseudolite systems not only improves position accuracy & signal availability but also reduces geometrical errors, especially Vertical Dilution of Precision (VDOP). Therefore, in this paper, a detailed analysis of positioning performance of combined GPS, NavIC and Pseudolite systems has been done using simulated data of GPS & NavIC generated from Spirent simulator combined with Pseudolite data from an identified location in India. Furthermore, data was corrupted by introducing Gaussian noise of 10 m mean & standard deviation of 3 m into generated ranges of GPS, NavIC & Pseudolite to assess the effect on position accuracy in the presence of noise. It has been observed from the analysis that the 3D position accuracy of combined GPS, NavIC & Pseudolite systems is reduced to 1.75 m from 10 m with NavIC only position. This is particularly useful for aviation applications where better vertical position accuracy is required.

Navigation on the lunar surface is extremely challenging, especially for autonomous rovers exploring its surface. The Space Applications Centre (SAC), Indian Space Research Organisation (ISRO) has proposed an autonomous, self-synchronized positioning system for lunar navigation using a network of pseudolite transceivers. These pseudolite transceivers are planned to be deployed on the lunar landers and will be transmitting signals in S-band frequency, identified frequency band for lunar navigation. This paper provides system requirement specifications of lunar pseudolite system including pseudolite transceivers, rover and all the sub-systems such as antenna, LNA Filter, transmitter and receiver. This paper also discusses pseudolite transceiver deployment methods, such as self-surveyed pseudolites. The ability of pseudolites and mobile rovers to communicate with each other has also been evaluated through preliminary link budget estimation. Additionally, the navigation processing algorithms suitable for lunar navigation have been proposed. Rover positioning in relative reference frames has also been implemented and tested using Systems Tool Kit (STK) generated data. Coverage analysis has been done along with the position accuracy. In conclusion, the proposed lunar surface navigation system seeks to provide way ahead for the exploration and research activities on the lunar surface by offering a reliable, stand-alone solution for autonomous rover navigation.

Interplanetary missions have always been an area of special interest for both space researchers and the general public. On Earth, we have a well-formed navigation system unlike other planets. Thus, a pseudolite-based system for rover navigation will be a better option. Whenever a rover lands on the surface of any planet other than the Earth, the main challenges come in its navigational aspects and its motion planning. The rover should be in the line of sight of the lander so that it can continuously send the results of its scientific experiments done on board. If it moves away from the lander, then it would be tragic in terms of efforts laid, finance, and the precious proofs which were collected by the rover. In this paper, we propose pseudolite-based rover navigation for future interplanetary missions using an Artificial Intelligence (AI)-based approach. In our proposed scheme, we have laid focus on three aspects. Firstly, on the calibration of the pseudolite position on the extra-terrestrial surface using bidirectional ranging which is a pre-requisite for navigation on other planets, where any manual intervention is not possible. Furthermore, navigation system needs to be intelligent enough so that whenever required, rover may take decisions autonomously using its own intelligence. This is where AI plays a significant role. We would be positioning the rover using bidirectional ranging measurements. It is a conventional double differencing technique with triangulation to find the position. Finally, the path planning of rover. The path planning would be done by the rover on board using artificial intelligence which has been integrated with bidirectional ranging for accurate positioning of rover while it is moving over the extra-terrestrial surface. The position of the rover was found up to a centimeter-level accuracy using five pseudolites while executing its motion planning algorithm.

The Search and Rescue (SAR) system and its functions are essential for location identification of spacecraft crew members. The existing (COSPAS-SARSAT) system provides distress alarm and position identification everywhere in the world. The existing COSPAS-SARSAT system is not able to determine location of emergency beacon due to large time delays and Doppler effects. To avoid Doppler effects in LEO orbit and longer delays in GEO orbit, SAR payloads on-board with GPS/GLONASS/Galileo MEO satellites to augmented COSPAS-SARSAT system in terms of service interiority, accuracy, and accessibility requirements. India has developed GPS-aided Geo augmented Navigation (GAGAN) for improving the positional accuracy of single-frequency GNSS users. The future SAR-based NavIC and GAGAN payloads would be very useful to improve the positional accuracy of people in emergency. There is a necessity of investigating the suitable search and rescue downlink broadcasts by GNSS in L-band. The location identification of spacecraft crew landing is a complicated task and requires fast computation within short time and with least positional errors. A suitable Short Message Service (SMS) can be developed to establish a bidirectional text communication between Space Segment and PBL users. The GNSS and SAR-based simulation tools, such as GPS PPP RTK, GAMP, Bernese GPS data processing software, and GLAB can be utilized. Deep learning-based ionospheric models, multipath, and ionospheric scintillation mitigation techniques can be developed in water beacon transmission environments. The outcome of this review article would be useful to investigate feasibility of NavIC GNSS for human spaceflight landing purposes.

This paper focuses on creating T-shaped planar antennas for radar applications utilizing High Frequency Structure Simulator (HFSS) software. Antenna factors such as return loss, gain, and radiation pattern are examined to find the best design for the X-Band RADAR application (8 GHz to 12 GHz). Through evaluation and comparison, it is determined that the H-shaped antenna, measuring 70 * 60 * 1.6, provides the best overall performance. This antenna has an efficient gain of 6.7 dB and an operational frequency of 9.02 GHz. The choice of the H-shaped design over other configurations indicates its superiority in addressing the requirements of RADAR systems operating within the defined frequency range. This work emphasizes the importance of simulation techniques such as HFSS in antenna design, which enables detailed analysis and optimization to obtain desired performance metrics. The discoveries contribute to upgrading antenna technology for radar applications, improving communication and sensing capabilities within the X-Band frequency range.

The Global Navigation Satellite Systems (GNSS) are constellations of navigation satellites, which assist in navigation and positioning applications. GNSS sensors or receivers can be used to acquire positioning data from the satellites and process them to obtain the coordinates of the user’s location. Real-time positioning is essential to provide or avail location-based services, like door delivery, mapping, etc. in smartphones. To achieve this purpose, low-cost GNSS chips are developed and are being used in many smartphones. This research presents a comprehensive analysis of signals from GPS, GLONASS, and NavIC constellations, focusing on the positioning accuracy of available smartphones and geodetic receiver. The required data is collected in single-frequency, dual-frequency supported smartphones and geodetic receiver. Data logging in smartphones is done by GPSTest and GnssLogger applications. The analysis shows the variability in parameters such as east, north, and up errors, dilution of precision (DOP) values, and accuracy parameters of Android smartphones with that of geodetic receiver under static open-sky condition. The DOP values of single-frequency smartphones obtained are better and more stable in terms of variation with time than those of dual-frequency smartphones. The accuracy obtained in single-frequency smartphones (with 2DRMS < 1) is higher than that in dual-frequency smartphones (with 2DRMS > 1).

In various global zones—equatorial, polar, and auroral—ionospheric scintillation proves a formidable hurdle to Global Navigation Satellite System (GNSS) performance. Over the past couple of decades, GNSS Radio Occultation (RO) has emerged as a vital resource, furnishing top-tier atmospheric data for seamless integration into Numerical Weather Prediction (NWP) models and the advancement of meteorological research. Nevertheless, scintillations disrupt measurements in satellite-to-satellite GNSS-RO geometry, influenced by solar flares, seasons, geomagnetic activity, geographical positions, and local time. These disturbances introduce positioning errors, deteriorating GNSS performance and underscoring the importance of accurate detection. Traditional algorithms often lack sensitivity, particularly in identifying strong scintillation due to its sporadic nature, leading to dataset imbalances. To address this, we’ve harnessed a myriad of machine learning (ML) algorithms to detect varying degrees of ionospheric scintillation, aiming to rectify dataset imbalances and bolster accuracy. Our study delves into Total Electron Content (TEC) and Ionospheric Phase Scintillation classification, predicting TEC using regressors like XGBoost Regressor, Autoregressive model (AR), and Exponential Smoothing model (ES), and classifying ionospheric phase scintillation using classifiers such as XGBoost, Naïve Bayes, and Light Gradient Boosting Machine (Light GBM). Through comprehensive comparative analysis, we evaluate regressors and classifiers using standard metrics like Mean Squared Error, Root Mean Squared Error, R2 Score, Accuracy, Recall, Precision, F1-Score, and Confusion Matrix.

Non-orthogonal multiple access (NOMA) is one of the most promising radio access techniques in next-generation wireless communications. The proposed use of a new transceiver design and non-orthogonal multiple access (NOMA) for MIMO uplinks exploits overall energy reduction while still meeting individual rate requirements by utilizing a new NOMA implementation scheme with group interference cancelation. Jamming attacks target NOMA communication. IMO technology is used to implement anti-jamming regulations in NOMA systems. Interference cancelation utilized to get rid of between groups interference, interference nulling at the transmitters and equalizers at the jointly designed receivers for improved power system efficiency. On the transmitter side, a novel interference nulling technique has been developed. The proposed NOMA scheme technique yields less total power consumption (dBm) compared to orthogonal multiple access (OMA) which can be used in aerospace and aeronautical wireless communication systems.

The escalating threat posed by enemy radars along national borders necessitates advanced strategic solutions for the deployment and maintenance of satellite constellations. This paper presents a comprehensive approach to designing a satellite constellation tailored for locating and neutralizing these threats, thereby enhancing the security of the aircraft. The primary motivation is to safeguard the security and operational effectiveness of military aircraft while maintaining a robust defense posture along the border. This study employs the Simplified General Perturbations 4 (SGP4) model to calculate essential parameters, including visibility, eclipse duration, and antenna tracking angles. Custom algorithms were created to meet the specific needs of this application, ensuring accuracy in both deployment and maintenance strategies. To determine the optimal number of satellites, trilateration was employed using simulated range values, assessing the accuracy and redundancy associated with varying satellite quantities. The analysis revealed that a six-satellite constellation, arranged in two orbital planes with precise angular separations, provides robust coverage and reliable radar detection capabilities. The deployment strategy, designed for cost-efficiency and effectiveness, involves launching and positioning the satellites with minimal post-launch adjustments. Maintenance maneuvers are systematically planned to ensure the constellation's sustained performance, accounting for perturbative forces and ensuring continuous surveillance. This study demonstrates the feasibility and strategic advantage of a well-designed satellite constellation for military defense applications. The proposed solution enhances early warning systems, ensuring a robust defense posture against enemy radar threats.

Harmful Algal Blooms (HABs) are known to be a natural phenomenon that is caused due to the cell growth of multiple phytoplankton species, which were present in both seawater and freshwater environments. These HABs severely impact fish mortalities, human health, environment and tourism, and economic fields. The detection and prediction of HABs over the Indian Ocean are needed. High-resolution satellite imagery MODIS and GEBCO bathymetry data provide an excellent opportunity to detect and predict HABs in spatial and temporal scales. In this paper, algal blooms identification using MODIS satellite data during 24 January 2004 and 1 August 2016 over the Indian ocean. It is evident that algal blooms are frequent in the Arabian Sea as compared eastern region of India. The outcome of this work would help apply machine learning algorithms for understanding the spatial–temporal variability of Algal blooms.

This paper presents the experimental and simulation results of a low-cost vehicle alarm tracking system using the nodeMCU and the Adafruit-Fona 808 GPS. Real-time field experiments are conducted in high-traffic areas in the Hyderabad urban area zones. With the aid of the free, open-source mapbox API programme, the collected data is projected on the maps to identify the zones. The zonal notion is used in the paper to remind the driver of the vehicle to drive safely and to alert the driver when entering from one zone to another zone. The developed prototype system’s preliminary results are encouraging in terms of alerting automobile drivers to avoid collisions.

Earthquake prediction remains a challenging scientific endeavor due to its complex nature and potentially devastating consequences. This study explores the possibility of using fluctuations in Total Electron Content (TEC) within the ionosphere as potential indicators of impending seismic activity. By analyzing data gathered from the BAKO station, an Autoregressive Moving Average (ARMA) model was utilized to anticipate TEC values preceding two significant earthquakes, one in Papua, Indonesia, occurring on February 5, 2004, and another in Western New Guinea on April 6, 2013. Evaluation of the predictive accuracy involves metrics such as Root Mean Square Error (RMSE), Mean Absolute Deviation (MAD), and Normalized RMSE (NRMSE). The findings suggest promise in the ARMA model’s ability to capture TEC variations associated with seismic events, discrepancies between predicted and actual TEC values are evident. This study offers valuable insights into the potential utility of TEC anomalies as precursors to earthquakes, underscoring the necessity for further research to refine prediction capabilities in this domain.

This study explores the effectiveness of deep learning models, particularly Bidirectional Long Short-Term Memory (BiLSTM) networks, in enhancing short-term solar irradiance forecasting. Accurate predictions of solar energy are crucial for efficient solar energy management, especially given the variability introduced by weather conditions. We investigate the ability of BiLSTM to detect complex patterns in historical solar data to improve forecasting accuracy. Our research includes rigorous preprocessing techniques and model selection to achieve optimal performance. Comparative analysis reveals that BiLSTM consistently outperforms traditional forecasting methods. For example, in summer, BiLSTM achieved a Mean Squared Error (MSE) of 0.0008, showing a 99.7% improvement over Linear Regression’s MSE of 0.244. In winter, BiLSTM demonstrated a 99.8% reduction in MSE compared to Linear Regression. The BiLSTM model’s R2 scores of 0.990 and 0.991 in summer and winter, respectively, significantly exceed those of traditional methods. This study underscores the potential of BiLSTM and deep learning in addressing key challenges in renewable energy forecasting, contributing to more effective energy planning and grid integration.

In various industries and sectors, the prevention of accidents is a paramount concern. In recent years, artificial intelligence (AI) techniques have emerged as powerful tools for enhancing accident prevention efforts. Leveraging AI in accident prevention offers the potential to reduce human error, predict and mitigate risks, and ultimately save lives. The current study provides an overview of how AI techniques are being employed to prevent accidents across different domains. The hazardous activities cause immediate danger to the workers or the high death rates in the activity are taken and the AI techniques are more effective in mitigating these accidents. AI-powered drones and robots can be used to inspect and monitor confined spaces, reducing the need for human workers to enter dangerous areas. Sensors and detectors can continuously monitor air quality within confined spaces. AI can predict when equipment located in confined spaces requires maintenance or repair. Incorporating AI in confined space safety not only reduces risks and improves worker safety but also enhances operational efficiency. Additionally, they should be used in conjunction with a comprehensive safety strategy that includes proper training, personal protective equipment, and emergency response protocols.