Transactions of the Japan Society for Aeronautical and Space Sciences最新文献_第10页

Measurement of Unsteady Aerodynamic Characteristics of a Heaving Wing in a Low Reynolds Number Flow 低雷诺数流中升沉机翼非定常气动特性的测量

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/TJSASS.64.147

M. Okamoto, Shota Fukatsu, D. Sasaki

{"title":"Measurement of Unsteady Aerodynamic Characteristics of a Heaving Wing in a Low Reynolds Number Flow","authors":"M. Okamoto, Shota Fukatsu, D. Sasaki","doi":"10.2322/TJSASS.64.147","DOIUrl":"https://doi.org/10.2322/TJSASS.64.147","url":null,"abstract":"The objective of this study is to determine the two-dimensional unsteady aerodynamic forces and moment acting on a heaving wing in a uniform flow using a wind tunnel. However, it is difficult to measure the aerodynamic forces acting on the heaving wing due to measuring device oscillation and the large inertial force of the wing model. In this study, a new type of wind tunnel test, named ‘‘heaving wind tunnel,’’ was developed. Here, the wing model remains stationary as the wind tunnel oscillates with a heaving motion. The advantage of this experimental method is that the measurement results are unaffected by the large inertial force acting on the oscillating wing model. Therefore, the wing model can be used in the same way as in steady state experiments. The normal force, thrust and pitching moment coefficients of a heaving airfoil were measured using the heaving wind tunnel test developed in this study. Through flow visualizations and pressure measurements, we found that the rapid drop in normal force coefficient after it reached its maximum value was due to a large growing leading-edge vortex.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68662625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

An Effective Maximal-Length Sequence Design for System Identification of a Continuous-Time Linear Aircraft Model 连续时间线性飞机模型系统辨识的有效最大长度序列设计

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/tjsass.64.215

A. Fujimori, S. Oh-hara

引用次数: 1

Efficient Navigation for Unmanned Agents in Sparse Wireless Sensor Networks 稀疏无线传感器网络中无人agent的高效导航

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/tjsass.64.283

Donghoon Kim

{"title":"Efficient Navigation for Unmanned Agents in Sparse Wireless Sensor Networks","authors":"Donghoon Kim","doi":"10.2322/tjsass.64.283","DOIUrl":"https://doi.org/10.2322/tjsass.64.283","url":null,"abstract":"Many works have reported on various sensor network position estimation methods based on the relative distance measurement that can be used when the global navigation satellite system is environmentally denied or degraded.1–3) Among others, trilateration algorithms are widely adopted because of their simple principle.4–6) However, the algorithms possibly fail if the sensors have a low range of communication or the environment includes obstacles.7) Typically, such distance-based localization algorithms are used to construct a globally rigid network.8,9) In other words, albeit each sensor, called node herein, has a limited transmission range, unmanned agents, like unmanned aerial vehicles (UAVs), should be inside the coverage space to receive the sensors’ information.10) Therefore, the typical algorithm requires a network that can adequately cover a certain area and must be capable of communicating with at least three sensors at any point in the area. However, such a network is not always guaranteed. This study proposes a strategy to maximize UAV’s navigation in a sparse wireless sensor network (SWSN) in the manner of the shortest distance travel. The overlapping (or localizable) area, which is calculated using the positions of three disks constructed by the sensor’s transmission range, is used to characterize the possibility of localizing UAVs through trilateration. To ensure that a UAV travels from a starting point to a destination point via the localizable area, it must pass the points that are defined by a sensor set, called vertices. The keys are to find such vertices to define a graph that is flexible to various network complexities that are determined by the combination of sensors and reduce the number of search nodes or the total distance. To determine the shortest path, the Dijkstra algorithm,11,12) one of the most widely used algorithms, is applied with proper modifications. The feasibility of the proposed method is verified through twodimensional (2D) and 3D examples.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68663291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Application of Deep Galerkin Method to Solve Compressible Navier-Stokes Equations 深度伽辽金方法在求解可压缩Navier-Stokes方程中的应用

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/tjsass.64.348

M. Matsumoto

引用次数: 4

Attitude Estimation Using Parallel Quaternion Particle Filter Based on New Quaternion Distribution 基于新四元数分布的并行四元数粒子滤波姿态估计

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/tjsass.64.249

Zhaihe Zhou, Zhong Yulu, Chuanwei Zeng, Xiangrui Tian

引用次数: 1

Simulation and Evaluation of a Space Station Operational Plan Considering Launch Delay of Cargo Vehicles 考虑货运飞船发射延迟的空间站运行计划仿真与评估

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/tjsass.64.50

Shuai Guo, Jin Zhang, Ya-zhong Luo

{"title":"Simulation and Evaluation of a Space Station Operational Plan Considering Launch Delay of Cargo Vehicles","authors":"Shuai Guo, Jin Zhang, Ya-zhong Luo","doi":"10.2322/tjsass.64.50","DOIUrl":"https://doi.org/10.2322/tjsass.64.50","url":null,"abstract":"Efficient operation is important to make full use of the capabilities of China’s space station. Determining the stochastic impacts of emergencies on the operational scenario of the space station is critical for successful implementation. However, few studies have assessed the uncertainties in the operational processes of the space station. To fill this gap, discrete event simulation (DES) is used to develop an evaluation method for the contingent operational plan of a space station. First, DES is used to develop a model framework of the space station operations, and the launch delay of cargo vehicles is introduced into the integrated simulation procedure. Second, the precision of the results and the computational efficiency are improved using the variance reduction technique. The corresponding effect on the number of simulation trials is confirmed using four constraints and three measurable metrics. Finally, the proposed method is applied to a two-year space station operational plan. The results show that maintaining a short interval between the launch date of the cargo vehicles and the start of the launch windows can decrease prolonged duration after a launch delay. A statistical analysis can be used to determine a safe interval between the dates of the events and vehicle launch.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"64 1","pages":"50-62"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68663794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Performance Evaluation on Packet Transmission for Distributed Real-time Avionics Networks Using Forward End-to-End Delay Analysis 基于前向端到端时延分析的分布式实时航电网络分组传输性能评估

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/tjsass.64.1

Qingfei Xu, Xinyu Yang

{"title":"Performance Evaluation on Packet Transmission for Distributed Real-time Avionics Networks Using Forward End-to-End Delay Analysis","authors":"Qingfei Xu, Xinyu Yang","doi":"10.2322/tjsass.64.1","DOIUrl":"https://doi.org/10.2322/tjsass.64.1","url":null,"abstract":"With growing avionics applications, the transmission of avionics data ﬂ ows has been increasing in real-time avionics networks of aircraft. An Avionics Full DupleX switched Ethernet (AFDX), standardized as ARINC 664, is chosen as the backbone network for distributed real-time avionics systems as it o ﬀ ers high throughput and does not require global clock synchronization. Estimating the end-to-end transmission delay to validate the network performance is essential for both certi ﬁ cation and industrial research. Because of the various waiting times caused by the backlog (i.e., the pending packets in the output port of the visited switch), it is necessary and reasonable to compute the worst-case end-to-end transmission delay to validate network performance. Several approaches have been designed to compute the upper boundaries of end-to-end transmission delays, such as the Network Calculus approach and the Trajectory approach. In this paper, we focus on a new approach, Forward end-to-end delay Analysis (FA). This approach iteratively estimates the maximum backlog (i.e., number of pending packets) in each switch visited along the transmission path, so that the worst-case end-to-end transmission delay can be computed and the network performance evaluated. We also present the termination condition for this iterative estimation. The experiments demonstrate that this approach achieves a more accurate evaluation of transmission performance than the Network Calculus approach. A comparison with the exact upper boundaries obtained using the Model Checking approach shows the pessimism (i.e., overestimation) in FA. This paper analyses the reasons for that pessimism, and proposes future research.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68662478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Supersonic Ejector-Driving System under Low Pressure: A Performance Evaluation 超声速喷射器低压驱动系统的性能评价

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/TJSASS.64.156

M. Anyoji, D. Numata, H. Nagai, K. Asai

引用次数: 4

Launch Vehicle Classification for Decision-Making of Small Satellite Launch Options 面向小卫星发射方案决策的运载火箭分类

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/tjsass.64.234

Mengying Zhang, Q. Xu, Qingbin Zhang

{"title":"Launch Vehicle Classification for Decision-Making of Small Satellite Launch Options","authors":"Mengying Zhang, Q. Xu, Qingbin Zhang","doi":"10.2322/tjsass.64.234","DOIUrl":"https://doi.org/10.2322/tjsass.64.234","url":null,"abstract":"In recent years, there has been a steady increase in the small satellite launch market. With the rapid development of novel launchers, for small satellite owners and operators, how to e ﬀ ectively and e ﬃ ciently choose appropriate launch vehicles has become a major concern. Based on updated launch records, a reliable launch data source for multi-attribute evaluation and reclassi ﬁ cation is established. Using a statistical classi ﬁ cation process, active launch vehicles are classi ﬁ ed into ﬁ ve representative-in-class launchers on the basis of their capabilities and performance. Unlike the previous categorisation based on payload ability, this method captures launch cost, technology maturity, reliability and availability of each category within the current launch vehicles in service. Moreover, representatives are selected as the baseline types for the high-level planning and designing of complex small satellite launch missions. The analysis indicates that this study provides a valid statistical classi ﬁ cation and selection strategy of representative-in-class launch vehicles to support decision-making for rapid assessment on a large number of small satellite launch missions.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68662779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Feasibility Study on Real-time Observation of Flow Velocity Field using Sparse Processing Particle Image Velocimetry 稀疏处理粒子图像测速实时观测流场的可行性研究

IF 1.1 4区工程技术

Transactions of the Japan Society for Aeronautical and Space Sciences Pub Date : 2021-01-01 DOI: 10.2322/tjsass.64.242

Naoki Kanda, K. Nakai, Y. Saito, T. Nonomura, K. Asai

{"title":"Feasibility Study on Real-time Observation of Flow Velocity Field using Sparse Processing Particle Image Velocimetry","authors":"Naoki Kanda, K. Nakai, Y. Saito, T. Nonomura, K. Asai","doi":"10.2322/tjsass.64.242","DOIUrl":"https://doi.org/10.2322/tjsass.64.242","url":null,"abstract":"Active flow control such as the use of a plasma actuator has been gathering much attention. Its effectiveness in flow separation control has been investigated experimentally and numerically.1) However, the capability during highspeed airflow is limited due to the lack of the flow control effect. Hence, feedback control utilizing the real-time measurement of the flow state is expected to improve applicability.2) Because of the complexity and nonlinearity of the flow phenomena, feedback control based on not the local flow information, but the full-state or global flow information clearly appears to be better for the future feedback control of flows. The use of particle image velocimetry (PIV), which provides the instantaneous velocity field in laboratory measurement can be used for nearly full-state observation. Therefore, real-time PIV measurement of the flow field seems to be a powerful tool for flow control. The velocity field is calculated from the cross-correlation coefficient for each interrogation window of the particle images during the PIV measurement, but the number of windows that can be processed in a short duration is limited. This is because the PIV computational time is too long when real-time PIV measurement is applied to aerodynamic flow-control experiments, which have a shorter time scale than hydrodynamic experiments. In this study, reduced-order modeling is employed and reducing the calculation time is considered. The authors proposed sparse processing PIV (SPPIV) as a method to achieve the real-time nearly full-state estimation. The PIV measurement of the flow field around a NACA0015 airfoil model was conducted and the flow field obtained using SPPIV and the processing time were evaluated.","PeriodicalId":54419,"journal":{"name":"Transactions of the Japan Society for Aeronautical and Space Sciences","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68662851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17