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Investigation of Vaned-Recessed Casing Treatment in a Low-Speed Axial Flow Compressor, Part I: Time-Averaged Results 低速轴流压气机匣叶片凹槽处理的研究，第一部分:时间平均结果

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-28 DOI: 10.3390/aerospace10090764

M. Akhlaghi, Y. Azizi

{"title":"Investigation of Vaned-Recessed Casing Treatment in a Low-Speed Axial Flow Compressor, Part I: Time-Averaged Results","authors":"M. Akhlaghi, Y. Azizi","doi":"10.3390/aerospace10090764","DOIUrl":"https://doi.org/10.3390/aerospace10090764","url":null,"abstract":"This paper investigates the effects of two modifications to a vaned recessed casing treatment. First, the shape of a circular curve was used in the top of the treated casing. Second, a fully curved guide vane was also applied. The goals of the modifications are to enhance the flow recirculation as well as to relieve the low-speed flow, which is normally accumulated within the corners of the vaned recessed casing treatment. The solid casing in addition to the two vaned recessed configurations with 23.2% and 53.5% rotor blade tip axial chord exposure have been studied numerically. The results indicated that two mechanisms are involved in the stall margin enhancement. First, the circumferential pressure gradient is reduced for both configurations. The reduction in pressure gradient largely reduces the development of tip leakage vortex and, thus, the generation of low-speed fluid is diminished. Second, the main flow/tip leakage interface moves toward downstream and the movement of interface toward the leading edge is delayed. The second configuration with a greater rotor blade tip exposure enables extra flow recirculation due to decreasing surface area and, therefore, could be superior to the application of the first casing treatment configuration. The major streamlines within the casing treatment are also discussed. The time-averaged results are presented in this paper, while the unsteady results including instantaneous flow fields, origins of the unsteadiness and frequency analysis are discussed in part II.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"1 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79943594","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

Combustion Characteristics of a Swirl-Radial-Injection Composite Fuel Grain with Applications in Hybrid Rockets 旋流-径向喷射复合燃料颗粒燃烧特性及其在混合动力火箭上的应用

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-28 DOI: 10.3390/aerospace10090759

Ruoyan Wang, Xin Lin, Zezhong Wang, Kun Wu, Zelin Zhang, Jiaxiao Luo, Fei Li, Xilong Yu

{"title":"Combustion Characteristics of a Swirl-Radial-Injection Composite Fuel Grain with Applications in Hybrid Rockets","authors":"Ruoyan Wang, Xin Lin, Zezhong Wang, Kun Wu, Zelin Zhang, Jiaxiao Luo, Fei Li, Xilong Yu","doi":"10.3390/aerospace10090759","DOIUrl":"https://doi.org/10.3390/aerospace10090759","url":null,"abstract":"The combustion characteristics of a swirl-radial-injection composite fuel grain were experimentally and numerically investigated. This composite grain permits swirl-radial oxidizer injection based on three hollow helical blades, each having a constant hollow space allowing uniform oxidizer injection into the main chamber along the axial direction. The oxidizer enters from channel inlets located along a hollow outer wall. This wall, together with the three blades, is fabricated as one piece from acrylonitrile-butadiene-styrene using three-dimensional printing. Paraffin-based fuel is embedded in the spaces between adjacent blades. Firing tests were conducted with gaseous oxygen as the oxidizer, using oxidizer mass flow rates ranging from 7.45 to 30.68 g/s. Paraffin-based fuel grains using conventional fore-end injection were used for comparison. Regression rate boundaries were determined taking into account the erosion of the oxidizer channels. The data show that the regression rate was significantly increased even at the lower limit. Images of the combustion chamber flame and of the exhaust plume were also acquired. The flame was found to be concentrated in the main chamber and a smoky plume was observed, consistent with the high regression rate. A three-dimensional simulation was employed. The present design was found to improve fuel/oxidizer mixing and combustion efficiency compared with a fuel grain using fore-end injection. Both the experimental results and numerical simulations confirmed the potential of this swirl-radial-injection fuel grain.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"205 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89398038","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

Investigation of Vaned-Recessed Casing Treatment in a Low-Speed Axial-Flow Compressor, Part II: Unsteady Results 低速轴流压气机匣叶片凹槽处理的研究，第二部分:非定常结果

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-28 DOI: 10.3390/aerospace10090763

M. Akhlaghi, Y. Azizi

{"title":"Investigation of Vaned-Recessed Casing Treatment in a Low-Speed Axial-Flow Compressor, Part II: Unsteady Results","authors":"M. Akhlaghi, Y. Azizi","doi":"10.3390/aerospace10090763","DOIUrl":"https://doi.org/10.3390/aerospace10090763","url":null,"abstract":"In this paper, unsteady characteristics of a modified vaned-recessed casing treatment with 23.2% rotor blade tip axial chord exposure were studied numerically. The modifications to the traditional vaned-recessed casing treatments were composed of geometrical amendments to the casing treatment’s guide vanes and the top of the treated casing. The solid casing and the casing treatment configurations were simulated using the Unsteady Reynolds-Averaged Navier–Stokes equations (URANS), and the results were validated by experimental results. Firstly, standard deviation and frequency analysis were performed to find the sources of unsteadiness. Secondly, velocity components analysis, including velocity triangles, was presented instantaneously to clarify their effects on rotor tip flow fields as well as stall margin improvement. Thirdly, unsteady interactions between the rotor and casing treatment flow fields, including flow structure and pressure distributions, were discussed. In the end, flow streamline patterns, in addition to the physical mechanism of the vaned-recessed casing treatment, were also discussed. The results indicated that unsteadiness plays an important role in the flow mechanism and cannot be ignored. The unsteadiness increases as the mass flow is reduced toward the stall/surge condition. Moreover, the analysis of velocity components demonstrated that the casing treatment has distinct behavior at the last operating points before the onset of the stall for solid casing and casing treatment configurations in terms of axial velocity change.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"17 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81023223","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

Condition-Based Maintenance in Aviation: Challenges and Opportunities 航空状态维修:挑战与机遇

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-28 DOI: 10.3390/aerospace10090762

W. Verhagen, B. F. Santos, F. Freeman, Paul van Kessel, D. Zarouchas, T. Loutas, R. Yeun, I. Heiets

引用次数: 0

Experiment and Numerical Simulation on Damage Behavior of Honeycomb Sandwich Composites under Low-Energy Impact 蜂窝夹层复合材料低能冲击损伤行为试验与数值模拟

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-27 DOI: 10.3390/aerospace10090756

Xiaoxia Zheng, Bohan He, Yuexian Zou, Q. Yang, Yupeng Cao, Zhiqiang Li, Yaokun Han

{"title":"Experiment and Numerical Simulation on Damage Behavior of Honeycomb Sandwich Composites under Low-Energy Impact","authors":"Xiaoxia Zheng, Bohan He, Yuexian Zou, Q. Yang, Yupeng Cao, Zhiqiang Li, Yaokun Han","doi":"10.3390/aerospace10090756","DOIUrl":"https://doi.org/10.3390/aerospace10090756","url":null,"abstract":"It is well-established that the honeycomb sandwich composite structures are easily prone to damage under low-energy impact. Consequently, it would lead to a dramatic decrease in structural load-bearing capacity and a threat to overall safety. Both experimental and numerical simulations are carried out to investigate the impact damage behavior of honeycomb sandwich composite specimens. The damage mode, damage parameters, and contact force-time curves of three types of panel materials with T300, T700, and T800 are obtained under different impact energies of 10 J, 20 J, and 40 J by the drop-weight impact experiment. Moreover, digital image correlation (DIC) tests are used to measure the deformation and strain of the lower panel. The experimental results reveal that the degree of damage increases with increasing impact energy. Particularly, the T300 panel specimen exhibits visible fiber fracture when subjected to an impact energy of 40 J. The impact process involves matrix cracking, fiber fracture, and delamination of the upper panel occurring first, followed by immediate crush damage to the honeycomb core and, finally, slight fiber damage to the lower panel. Due to its higher strength, the T800 panel specimen exhibits the highest damage resistance compared to the T700 and T300 panel specimens. To consider the microscopic failure criteria and various types of contact during the impact process, a finite element model of honeycomb sandwich composites is established, and numerical simulation analysis of low-energy impact is performed to determine the damage mode, damage size, and contact-force curves. Comparative analysis demonstrates good agreement between the simulation and experimental results. The findings of this study provide valuable technical support for the widespread application of honeycomb sandwich composites in the aviation field.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"101 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76990717","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

Air Channel Planning Based on Improved Deep Q-Learning and Artificial Potential Fields 基于改进深度q -学习和人工势场的风道规划

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-27 DOI: 10.3390/aerospace10090758

Jie Li, Di Shen, Fu-ping Yu, Renmeng Zhang

{"title":"Air Channel Planning Based on Improved Deep Q-Learning and Artificial Potential Fields","authors":"Jie Li, Di Shen, Fu-ping Yu, Renmeng Zhang","doi":"10.3390/aerospace10090758","DOIUrl":"https://doi.org/10.3390/aerospace10090758","url":null,"abstract":"With the rapid advancement of unmanned aerial vehicle (UAV) technology, the widespread utilization of UAVs poses significant challenges to urban low-altitude safety and airspace management. In the coming future, the quantity of drones is expected to experience a substantial surge. Effectively regulating the flight behavior of UAVs has become an urgent and imperative issue that needs to be addressed. Hence, this paper proposes a standardized approach to UAV flight through the design of an air channel network. The air channel network comprises numerous single air channels, and this study focuses on investigating the characteristics of a single air channel. To achieve optimal outcomes, the concept of the artificial potential field algorithm is integrated into the deep Q-learning algorithm during the establishment of a single air channel. By improving the action space and reward mechanism, the resulting single air channel enables efficient avoidance of various buildings and obstacles. Finally, the algorithm is assessed through comprehensive simulation experiments, demonstrating its effective fulfillment of the aforementioned requirements.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"34 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82737413","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

Robust Controller Design for a Generic Helicopter Model: An AI-Aided Application for Terrain Avoidance 通用直升机模型鲁棒控制器设计:人工智能辅助地形规避应用

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-27 DOI: 10.3390/aerospace10090757

Barış Başpınar

引用次数: 1

Feasibility and Performance Analysis of High-Energy-Density Hydrocarbon-Fueled Turboexpander Engine 高能量密度碳氢燃料涡轮膨胀发动机的可行性及性能分析

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-25 DOI: 10.3390/aerospace10090753

Jin Gao, Ziyi Kang, Weiheng Sun, Youyin Wang, Junlong Zhang, W. Bao

{"title":"Feasibility and Performance Analysis of High-Energy-Density Hydrocarbon-Fueled Turboexpander Engine","authors":"Jin Gao, Ziyi Kang, Weiheng Sun, Youyin Wang, Junlong Zhang, W. Bao","doi":"10.3390/aerospace10090753","DOIUrl":"https://doi.org/10.3390/aerospace10090753","url":null,"abstract":"With the in-depth research on hypersonic aerodynamics and hypersonic propulsion technology, humans are growing closer to space travel. Recent studies have shown that the pre-cooled air-turborocket (ATR) or turboexpander engines are some of the potential propulsion methods for reusable space vehicles and single stage-to-orbit (SSTO) missions because they have a high specific impulse at low Mach numbers, which can overcome the problem of the “thrust gap” in turbine-based combined-cycle (TBCC) engines. The ATR engine needs an additional oxidizing agent and the turboexpander engine usually uses hydrogen as fuel, which has low energy density and poor safety. To address this problem, this paper proposed a high-energy-density (HED) hydrocarbon-fueled turboexpander engine, and its feasibility has been proven through a simplified thermodynamic model. Through detailed thermodynamic analysis based on the energy and pressure balance, this paper analyzed the performance characteristics of the engine to evaluate its capacity to work in a wide speed range at low Mach numbers. The results show that the endothermic hydrocarbon-fueled turboexpander engine has good specific impulse in Mach 0∼4 at an equivalence ratio of 0.7∼1.3, and the turboexpander engine can be combined with the dual-mode scramjet and become an efficient acceleration method for SSTO missions and the reusable spacecraft.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"118 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77388311","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

LoRa-Based Low-Cost Nanosatellite for Emerging Communication Networks in Complex Scenarios 用于复杂场景下新兴通信网络的基于lora的低成本纳米卫星

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-25 DOI: 10.3390/aerospace10090754

Raúl Parada, Victor Monzon Baeza, David N. Barraca-Ibort, Carlos Monzo

{"title":"LoRa-Based Low-Cost Nanosatellite for Emerging Communication Networks in Complex Scenarios","authors":"Raúl Parada, Victor Monzon Baeza, David N. Barraca-Ibort, Carlos Monzo","doi":"10.3390/aerospace10090754","DOIUrl":"https://doi.org/10.3390/aerospace10090754","url":null,"abstract":"Wireless broadband coverage has reached 95% worldwide. However, its trend is expected to stay the same in the following years, presenting challenges for scenarios such as remote villages and their surrounding environments. Inaccessibility to these areas for installing terrestrial base stations is the main challenge to bridge the connectivity gap. In addition, there are emergencies, for instance, earthquakes or war areas, that require a fast communication reaction by developing networks that are less susceptible to disruption. Therefore, we propose a low-cost, green-based nanosatellite system to provide complete coverage in hard-to-reach areas using long-range communication. The system comprises a pilot station, a base station, and a CubeSat with sensor data collector capabilities acting as a repeater. Our system can be built within hours with a 3D printer using common material, providing a flexible environment where components can be replaced freely according to user requirements, such as sensors and communication protocols. The experiments are performed in Spain by two test sets validating the communication among all components, with RSSI values below −148 dBm and the longest distance above 14 km. We highlight the reduction in the environmental impact of this proposal using a balloon-based launch platform that contributes to sustainable development.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"1 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73401940","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

Assessment of Asteroid Classification Using Deep Convolutional Neural Networks 基于深度卷积神经网络的小行星分类评估

IF 0.1 4区工程技术

Aerospace America Pub Date : 2023-08-25 DOI: 10.3390/aerospace10090752

V. Bâcu, C. Nandra, A. Sabou, T. Stefanut, D. Gorgan

{"title":"Assessment of Asteroid Classification Using Deep Convolutional Neural Networks","authors":"V. Bâcu, C. Nandra, A. Sabou, T. Stefanut, D. Gorgan","doi":"10.3390/aerospace10090752","DOIUrl":"https://doi.org/10.3390/aerospace10090752","url":null,"abstract":"Near-Earth Asteroids represent potential threats to human life because their trajectories may bring them in the proximity of the Earth. Monitoring these objects could help predict future impact events, but such efforts are hindered by the large numbers of objects that pass in the Earth’s vicinity. Additionally, there is also the problem of distinguishing asteroids from other objects in the night sky, which implies sifting through large sets of telescope image data. Within this context, we believe that employing machine learning techniques could greatly improve the detection process by sorting out the most likely asteroid candidates to be reviewed by human experts. At the moment, the use of machine learning techniques is still limited in the field of astronomy and the main goal of the present paper is to study the effectiveness of deep convolutional neural networks for the classification of astronomical objects, asteroids in this particular case, by comparing some of the well-known deep convolutional neural networks, including InceptionV3, Xception, InceptionResNetV2 and ResNet152V2. We applied transfer learning and fine-tuning on these pre-existing deep convolutional networks, and from the results that we obtained, the potential of using deep convolutional neural networks in the process of asteroid classification can be seen. The InceptionV3 model has the best results in the asteroid class, meaning that by using it, we lose the least number of valid asteroids.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"45 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85952711","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