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2024 | Book

2023 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2023) Proceedings

Volume II


About this book

This book is a compilation of peer-reviewed papers from the 2023 Asia-Pacific International Symposium on Aerospace Technology (APISAT2023). The symposium is a common endeavour among the four national aerospace societies in China, Australia, Korea and Japan, namely, Chinese Society of Aeronautics and Astronautics (CSAA), Royal Aeronautical Society Australian Division (RAeS Australian Division), Japan Society for Aeronautical and Space Sciences (JSASS) and Korean Society for Aeronautical and Space Sciences (KSAS). APISAT is an annual event initiated in 2009. It aims to provide the opportunity to Asia-Pacific nations for the researchers of universities and academic institutes, and for the industry engineers to discuss the current and future advanced topics in aeronautical and space engineering.

This is the volume II of the proceedings.

Table of Contents

Design and Development of Ground Testing Benches for Aircraft Electric Propulsion Systems
With the development of electric storage technology and power electronics technology combined with the continuous promotion and popularization of Renewable energy, More-Electric and All-Electric Aircraft have gradually become a development trend. In order to further verify the performance of electric power systems and mitigate the risks of unproven electrical powertrain systems, the performance verification test of electric propulsion system for electric aircraft is necessary. In this paper, a set of electric aircraft electric propulsion system ground test bench was developed and built, including thruster force testing units, digital acquisition system, cooling and thermal management system, battery power system, Human Machine Interface and other software developing parts. The testing methods were discussed in this paper which uses lithium battery as the power unit, with cooling thermal management system, and high accurate measuring and control units. The performance parameters of the motor and propeller under testing have been compared and analyzed with baseline values.
Shuhao Deng, Tao Lei, Da Kang, Lina Song, Xingyu Zhang, Xiaobin Zhang
CFD Discrete Error Estimation of Low-Aspect-Ratio Flying-Wing Aircraft on Large Attack Angle
The low-aspect-ratio flying-wing (LARFW) is widely used in the design of high-speed aircraft, and it is very important to obtain high-accurate prediction of aerodynamic characteristics. Therefore, how to reduce the discrete error in numerical simulation is always the goal of Computational Fluid Dynamics (CFD), especially at high attack angle. The adjoint equation establishes the relationship between the local residuals and the global discretization error of the objective function, which can directly measure the effect of spatial mesh discretization on the simulation error of aerodynamic characteristics. Based on discrete adjoint theory and hybrid mesh, this paper developed a discrete error estimation and spatial mesh adaptation method, which could quantitatively evaluate the discrete errors caused by spatial grids, correct the errors of aerodynamic characteristics and guide the mesh adaptation optimization, and finally improve the computational accuracy of aerodynamic characteristics of aircraft. Based on the adjoint error estimation method, the spatial discretization error of a LARFW aircraft at a high Angle of attack is studied in this paper. Numerical results show that the discrete errors at the head of aircraft, the leading edge of the wing-body, the separation area at the leeward side, and the high-pressure area of the windward side are very large on high attack angle. From the perspective of flow mechanism, the separated vortices at the wing tip generate and develop at these regions, which have a great influence on aerodynamic characteristics of the LARFW aircraft. Besides, the results in this paper can provide a theoretical support for the grid generation in the numerical simulation of LARFW aircraft at large attack angle.
Pengcheng Cui, Huan Li, Hongyin Jia, Xiaojun Wu, Jiangtao Chen, Jing Tang, Guiyu Zhou, Mingsheng Ma, Jun Gao, Wentong Cui, Naichun Zhou
Effect of Machining Parameters on the Residual Stress Distribution and Surface Roughness in Ti-6-Al-4V Alloy
The residual stress and the surface roughness are the critical input when conducting the safety analysis of the aero-engine components because the surface integrity of the machining process may affect the fatigue life of the aero-engine components. To obtain the residual stress distribution and surface roughness, the analytical and finite element method have been developed to obtain the stress and temperature fields. However, the analytical and finite element methods are based on many assumptions and fail to predict accurately. Thus, there is an absence of models that can be used to predict the residual distribution. Therefore, this paper established the database of residual stress and surface roughness in Ti-6-Al-4V alloy under different machining parameters to provide the core input to the safety or reliability analysis of the critical components. Specifically, the machining parameters of Ti-6-Al-4V alloy refer to the actual manufacturing process, and the cutting speed ranges from 30 to 95 m/min, the cutting feed ranges from 0.05 to 0.2 mm/r, and the cutting depth ranges from 0.01 to 0.5 mm. Results show that the cutting process on the Ti-6-Al-4V alloy mainly generates compressive residual stress ranging from −550 MPa to −300 MPa, and the residual stress layer depth is around 200–600 μm. The surface residual stress mainly depends on the cutting feed rate, while the residual stress depth is related to the cutting speed. The surface roughness Ra ranges from 0.388 to 4.430 μm, mainly depending on the feed rate.
Guo Li, Huimin Zhou, Junbo Liu, Shaochen Bao, Shuiting Ding, Mengyao Bao, Yang Liu, Zonghui Liu
Establishment Method for Hard-Alpha Defect Distribution Curve of Titanium Alloy of Aero-Engine Life-Limited Parts Considering the Effect of Hot Processing
Manufacturing defects in life-limited parts of aero-engines, such as hard alpha inclusions and machining scratches, seriously threaten the safety of the aero-engine. The probabilistic failure risk assessment method has been developed to quantitatively assess the impact of material and manufacturing defects on engine failure risk by assuming a material initial defects distribution curve. The distribution of melting defects hard alpha is the core input to the probabilistic failure risk analysis, which is significantly affected by hot processing, such as forging deformation ratio, deformation rate, and deformation temperature. However, limited research has been conducted to investigate the impact of hot working on defect distribution curves. Hence, this paper proposed a method for correcting titanium alloys’ internal hard alpha defect distribution curve. Firstly, based on the experimental data of the artificial hard-alpha defects, the constitutive model is established for the TiN material. Then, the finite element software DEFORM was used to simulate the thermal deformation model of the bar forging and hard-alpha inclusion deformation. Afterward, the thermal deformation law of the hard-alpha inclusion with forging was obtained. Finally, a hard-alpha defect deformation model is established based on the defect deformation law, and the correction line of the hard-alpha defect distribution curve is obtained. The error between the hard-alpha defect deformation model and the artificial preset defect forging test is less than 50%. The deformation model will be applied to correct the critical defect data of domestic titanium alloy materials and then establish the defect distribution curve that reflects domestic materials’ processing level. The correction curve can support the airworthiness forensics of domestic autonomous models.
Guo Li, Junbo Liu, Huimin Zhou, Suiting Ding, Mengyao Bao, Haibin Ji, Yusheng Cai
En Route AMAN Design Toward Sustainable Arrival Traffic Operation
A scientifically designed arrival manager (AMAN) for en route airspace, so-called En Route AMAN, is proposed. This AMAN aims to achieve environmental benefits by optimizing runway flow and inter-aircraft control for air traffic controllers (ATCos). First, stochastic distribution of inter-aircraft time and runway occupancy times are analyzed to design an airline-oriented runway assignment rule that selects a target to minimize arrival taxi time in cases of high demand at runway 34L. Second, the direct-to rule is applied to southbound traffic to runway 34R, depending on the volume of traffic from the north to 34R. Third, speed control rules are also formulated based on inter-aircraft spacing, using simulation-based optimization and decision tree analysis to capture stochastic features and the bottleneck of air traffic flow for ATCo in each en route airspace. An agent-based simulation is conducted to evaluate the effectiveness of the system in reducing fuel consumption due to arrival delays. The fuel consumption is estimated by using the fuel flow of the representative engine corresponding to the aircraft type sourced from the ICAO databank. The results demonstrate that the proposed En Route AMAN achieves a total fuel saving of 12.58 tons for approach in terminal airspace and 5.23 tons for taxiing per day. These findings suggest that implementing operationally feasible rules for ATCos could mitigate environmental impacts while ensuring interpretability and feasibility.
Katsuhiro Sekine, Tomoaki Tatsukawa, Kozo Fujii, Eri Itoh
Characteristics of the Effective Cross-Sectional Area Reduction of the Turbine Nozzle Throat and Engine Performance of KSLV-II
The engines for the Korea Space Launch Vehicle-II (KSLV-II) are liquid oxygen/kerosene gas generator cycle engine. The turbine is driven by fuel rich gas of the gas generator. The turbine gas in kerosene-fueled engines contains a large amount of soot, which leads to a decrease in the turbine nozzle throat area as it burns. Understanding this characteristic is essential as it affects the performance of the engine during flight. In this paper, the authors observed the changes in the turbine nozzle throat area of the KSLV-II engines as a function of burning time to determine the performance characteristics of the engine. Since the turbine nozzle throat area cannot be directly measured during flight or firing tests on the ground, the effective cross-sectional area of the turbine was estimated using pressure and temperature ratios across the turbine rotor. The discharge coefficient variations of KSLV-II 1st and 3rd stage engine’s turbine nozzle throat in the development firing tests were analyzed. Although it is evident that carbon accumulates on the turbine nozzle over time, the detachment of this carbon and the restoration of the turbine's effective area occur in a seemingly random manner.
Chang-Ho Nam, Soon Young Park, Yoonwan Moon
Sensitivity Analysis of Infrared Radiation from Tailless Aircraft Nozzle Caused by Incoming Conditions
Exhaust system is the most important infrared radiation source of aircraft. The special geometric structure of serpentine nozzle can partially or completely block the internal high-temperature components. It can enhance the mixing between high-temperature gas and external low-temperature atmosphere with two-dimensional nozzle, and can effectively reduce the infrared radiation intensity of aircraft. The distribution characteristics of nozzle wall temperature, gas temperature and pressure and gas component concentration under different flight parameters are analyzed. Based on the discrete transfer method, the infrared radiation characteristics of nozzle are evaluated, and the influence of incoming flow parameters on the infrared radiation characteristics of nozzle is obtained. Taking flight altitude H, flight Mach number Ma, nozzle mainstream total pressure P0 and nozzle mainstream total temperature T0 as uncertain input parameters, samples are constructed by Latin Hypercube Sampling (LHS), and the infrared radiation response values corresponding to each sample point are calculated. The sensitivity analysis of infrared radiation signals is carried out by Non-intrusive Polynomial Chaos (NIPC) method, and the influence degree of single variable and multiple variables on the infrared radiation characteristics of nozzle is quantified. Infrared radiation intensity is the most sensitive to the total temperature of the nozzle. The Sobol index of gas radiation, wall radiation and total radiation and its total temperature reaches above 0.7, which is dominant. The contribution of Mach number to infrared radiation intensity can be ignored basically. Infrared radiation intensity is also sensitive to flight altitude. The gas radiation is the most sensitive to the flight altitude, but the total radiation is the most sensitive to the temperature, and the infrared radiation intensity mainly comes from the wall radiation in the direction of 90 degrees of horizontal detection plane and 90 degrees of vertical detection plane.
Chengjun He, Bowen Shu, Jiangtao Huang, Cheng Chen, Xian Chen, Haibo Zheng
Analysis of Air Traffic Time Predictability for International ATFM
International air traffic flow management (ATFM) will become increasingly necessary to avoid congestion as traffic recovers after the COVID-19 pandemic. As AFTM measures in the Asia/Pacific region, Calculated Time Over (CTO) at Flight Information Region (FIR) boundary fixes and Calculated Take-Off Time (CTOT), which are enabled by greater cross-border flight data and trajectory sharing and are targeted at individual flights, are replacing blanket miles/minutes in trail restrictions. However, their effectiveness depends on trajectory prediction accuracy and the conformance of flights to the cleared trajectory. To help understand prediction accuracy and factors affecting flight time conformance in order to construct better models, we analyse case-study traffic flows from Fukuoka FIR to Incheon FIR and Incheon FIR to Shanghai FIR. We present the flow characteristics through SAPRA and AGAVO, and analyse departure time predictability from Narita airport (RJAA), flight time from RJAA to SAPRA, and flight time from Incheon airport (RKSI) to AGAVO, using historical data from before the pandemic.
Mark Brown, Hiroko Hirabayashi, Takashi Imuta, Daekeun Jeon, Keumjin Lee, Yanjun Wang, Naomi Hani Gray, Hongah Chai
Streamline Fin Structure Design and Optimization Based on Simulation
Heat exchangers have been widely applied in the fields of aerospace, petrochemical, air separation and transportation due to high heat transfer efficiency. Fins, as the main heat transfer structure of plate fin heat exchangers, greatly affect the efficiency of heat exchangers. Streamline fins including lozenge, airfoil and conical fins, have been designed to optimize the serrated fin in this paper. FLUENT software has been applied to simulate and analyze the changes of their flow and heat transfer characteristics, and evaluate the fin performance. The comprehensive performances of five types of fin channels, formed from these three kinds of streamlined fins, have been analyzed and compared in order to improve heat transfer and decrease flow resistance. The research results show that asymmetric airfoil can enhance fluid disturbance and heat transfer, the NACA 0024 airfoil fin has the best heat transfer performance while reducing resistance by 21.2% – 25.2%, lozenge fin has the highest comprehensive performance and can reduce resistance by 50% – 53.5% although its heat transfer performance has decreased. According to the research results, these streamline fins will play important roles in enhancing heat transfer of heat exchanger application.
Liang Lanxin, Hu Liang, Li Jiayu
A Vision-Based Close Approach for KITSAT-1 Capture
The active remove of space debris has been coming up the issue for stabilizing the space environments these days. In line with this, KAIST Satellite Technology Research Center (SaTReC) intends to conduct the project to capture KITSAT-1, launched on August 11, 1992 as Korea’s first artificial satellite. As an ADR purpose, we could approach to the KITSAT-1 based on the TLE information provided by CSpOC (Combined Space Operation Center). However, TLE information and its orbit propagation error are not sufficient to rendezvous to KITSAT-1. Therefore, in this paper, we applied vision-based navigation and control concept at after it reaches close to KITSAT-1 for vision-based navigation using same type as previously developed star tracker. As a simulation result, we verified that the chaser satellite could reached to closely enough to capture KITSAT-1 without TLE orbit information.
Taejin Chung, Chiwook Oh, Soongoo Kim
Methods for Combination Optimization of Flight Routes and Flight Altitude Considering Restrictions in Free Route Airspace
In order to reduce the cost of aircraft flights and air pollution emissions when flying through Free Route Airspace (FRA), methods have been developed to jointly optimize flight paths and flight altitudes. First, cost models for calculating different optimization objectives such as fuel cost, CO2 cost, contrail cost, time cost, total flight cost are proposed. Then, we improve the algorithm based on the traditional Dijkstra’s algorithm to solve the dynamic edge weight problem by taking into account the effect of the aircraft fuel consumption on the aircraft weight and the associated emission parameters. The results show that compared with the most fuel-efficient trajectory, the minimum contrail cost trajectory reduces the contrail cost by 65.65%, while the minimum emission cost trajectory reduces the contrail cost, the emission cost, and the total flight cost, respectively by 64.26%, 15.34% and 1.76%, and the minimum total flight cost trajectory reduces the contrail cost, the emission cost, and the total flight cost respectively, by 46.67%, 11.86% and 1.94%.
Na Wang, Zhiqiang Wei, Luhuan Wei, Yi Hui
Fundamental Study on Aerodynamic-Driven Topology Optimization of Compliant Morphing Airfoil Using Panel Method
This study aims to develop an optimal design method that simultaneously explores the optimal morphing shape and the internal structural configuration without setting a predefined target shape to obtain a morphing airfoil structure that is superior in terms of both aerodynamic and structural performances. A panel method is adopted to evaluate the aerodynamic performance, which provides a good estimate of the aerodynamic characteristics of the airfoil profile, with low computational cost and low fidelity. The structure is modeled by finite element method, and the structural configuration that improves the aerodynamic performance evaluated by the panel method is obtained by the topology optimization. Additionally, the sensitivity, which is a guideline for the optimum design search to improve the aerodynamic performance, is derived to efficiently perform the optimization. In this paper, the proposed method is applied to the stiffness maximization problem of an airfoil internal structure subjected to aerodynamic loading as a benchmark problem. Through this numerical example, the validity of the proposed method is discussed by investigating the structural performance of the obtained optimized structural configurations under different aerodynamic loads.
Keita Kambayashi, Nozomu Kogiso
Wall Pressure Fluctuations on a Cone-Cylinder Model at Transonic Regime
Flow induced vibrations and interior noise are inevitable issues for aerospace vehicle design. Panel vibrations under fluctuating pressure excitation can cause fatal damage to aerospace vehicle structures. In order to identify the characteristics of wall pressure fluctuations, wind tunnel test using a cone-cylinder model is performed. The test is conducted at transonic Mach numbers and for variable angle of incidence which are the most critical in terms of occurrence of flow instability. The root-mean-square values of fluctuating pressures (Prms) reveal that the ogive of cone-cylinder is usually critical region to encounter large Prms values as flow separation occurs here. Also, at large mach numbers, shockwave arises on the cylinder and moves downstream as upstream flow speed increases. At transonic regime the shockwave is usually unstable and easily oscillating, which induces severe flow conditions around the cylinder. The test suggests that shockwave oscillation and flow separation are the typical environments which induce large fluctuating pressures. Mach number is the key parameter to influence flow condition as it determines the strength of flow separation and shockwave instability. Angle of incidence appears not to influence the fluctuating pressure significantly.
Chang Liu, Chen Ji, Lei Zhao
2023 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2023) Proceedings
Song Fu
Copyright Year
Springer Nature Singapore
Electronic ISBN
Print ISBN

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