Pub Date : 2023-12-29DOI: 10.3390/aerospace11010036
Yousef Gharbia, J. Derakhshandeh, Md. Mahbub Alam, A. M. Amer
Wingtip vortices generated from aircraft wingtips, as a result of the pressure differential at the wingtip, constitute a major component of the total drag force, especially during take-off and landing. In addition to the drag issue, these vortices also pose a significant hazard to smaller aircraft flying in the wake of the larger airplane. The wingtip vortices play a crucial role in aerodynamic efficiency, fuel consumption, flight range, and aircraft stability. This paper presents an overview of the volume of work conducted over the past six decades to encapsulate the phenomena and the techniques devised to mitigate the wingtip vortices. It is shown that the aerodynamic efficiency of the examined wingtip devices ranges from 1% to 15%, depending on the type of wingtips and the flight conditions. Furthermore, it is pointed out that the decrease in fuel consumption ranges from 3.4% to 10%, and the reduction in the induced drag ranges from 5% to 20%.
{"title":"Developments in Wingtip Vorticity Mitigation Techniques: A Comprehensive Review","authors":"Yousef Gharbia, J. Derakhshandeh, Md. Mahbub Alam, A. M. Amer","doi":"10.3390/aerospace11010036","DOIUrl":"https://doi.org/10.3390/aerospace11010036","url":null,"abstract":"Wingtip vortices generated from aircraft wingtips, as a result of the pressure differential at the wingtip, constitute a major component of the total drag force, especially during take-off and landing. In addition to the drag issue, these vortices also pose a significant hazard to smaller aircraft flying in the wake of the larger airplane. The wingtip vortices play a crucial role in aerodynamic efficiency, fuel consumption, flight range, and aircraft stability. This paper presents an overview of the volume of work conducted over the past six decades to encapsulate the phenomena and the techniques devised to mitigate the wingtip vortices. It is shown that the aerodynamic efficiency of the examined wingtip devices ranges from 1% to 15%, depending on the type of wingtips and the flight conditions. Furthermore, it is pointed out that the decrease in fuel consumption ranges from 3.4% to 10%, and the reduction in the induced drag ranges from 5% to 20%.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":" 10","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139142786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-29DOI: 10.3390/aerospace11010037
K. Yeranee, Yu Rao, Chao Xu, Yueliang Zhang, Xiyuan Su
Additive manufacturing allows the fabrication of relatively complex cooling structures, such as triply periodic minimal surface (TPMS), which offers high heat transfer per unit volume. This study shows the turbulent flow heat transfer and thermal stress of the Diamond-TPMS topology in the gas turbine blade trailing edge channel. The thermal-fluid-solid analysis of the Diamond-TPMS structure, made of directionally solidified GTD111, at the nearly realistic gas turbine condition is executed, and the results are compared with the conventional pin fin array at the Reynolds number of 30,000. Compared to the baseline pin fin structure, the Diamond-TPMS model distributes flow characteristics more uniformly throughout the channel. The overall heat transfer enhancement, friction factor ratio, and thermal performance are increased by 145.3%, 200.9%, and 32.5%, respectively. The temperature, displacement, and thermal stress in the Diamond-TPMS model are also distributed more evenly. The average temperature on the external surface in the Diamond-TPMS model is lower than the baseline pin fin array by 19.9%. The Diamond-TPMS network in the wedge-shaped cooling channel helps reduce the volume displacement due to the material thermal expansion by 29.3%. Moreover, the volume-averaged von Mises stress in the Diamond-TPMS structure is decreased by 28.8%.
{"title":"Turbulent Flow Heat Transfer and Thermal Stress Improvement of Gas Turbine Blade Trailing Edge Cooling with Diamond-Type TPMS Structure","authors":"K. Yeranee, Yu Rao, Chao Xu, Yueliang Zhang, Xiyuan Su","doi":"10.3390/aerospace11010037","DOIUrl":"https://doi.org/10.3390/aerospace11010037","url":null,"abstract":"Additive manufacturing allows the fabrication of relatively complex cooling structures, such as triply periodic minimal surface (TPMS), which offers high heat transfer per unit volume. This study shows the turbulent flow heat transfer and thermal stress of the Diamond-TPMS topology in the gas turbine blade trailing edge channel. The thermal-fluid-solid analysis of the Diamond-TPMS structure, made of directionally solidified GTD111, at the nearly realistic gas turbine condition is executed, and the results are compared with the conventional pin fin array at the Reynolds number of 30,000. Compared to the baseline pin fin structure, the Diamond-TPMS model distributes flow characteristics more uniformly throughout the channel. The overall heat transfer enhancement, friction factor ratio, and thermal performance are increased by 145.3%, 200.9%, and 32.5%, respectively. The temperature, displacement, and thermal stress in the Diamond-TPMS model are also distributed more evenly. The average temperature on the external surface in the Diamond-TPMS model is lower than the baseline pin fin array by 19.9%. The Diamond-TPMS network in the wedge-shaped cooling channel helps reduce the volume displacement due to the material thermal expansion by 29.3%. Moreover, the volume-averaged von Mises stress in the Diamond-TPMS structure is decreased by 28.8%.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":" 109","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139144948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A fan is part of the core equipment of a super-pressure balloon altitude control system, and high-performance fans have a significant impact on the altitude control capability and flight safety of super-pressure balloons. This paper proposes a mixed-flow MIX-140 fan for use with super-pressure balloons. Changes in the fan’s operating characteristics at various flight altitudes of a super-pressure balloon were investigated. First, the performance of the fan at ground level was obtained through numerical simulation and compared with measured data of the prototype to verify the accuracy of the simulation analysis. On this basis, the influences of changes in the atmospheric pressure, temperature, and fan speed on fan performance were investigated through numerical simulation. Furthermore, the MIX-140 fan was compared with an existing fan, and the variation of two parameters, namely, the ratio of inflation volume per unit time and the ratio of inflation volume per unit power, were investigated at different altitudes. Finally, the changes in the operating characteristics of the fan under different high-altitude environments were investigated through actual testing. The results reveal that changes in altitude can lead to significant changes in fan performance, and changes in the atmospheric pressure, temperature, and fan speed affect the fan’s working characteristics. Compared with the existing fan, the MIX-140 fan achieves an average increase of 295.8% in the inflation volume per unit of time, and 14.6% in the inflation volume per unit of power at altitudes of 16–20 km. The performance variation characteristics and testing methods of this proposed super-pressure balloon fan can provide a foundation and reference for the design of a super-pressure balloon control system.
{"title":"Analysis and Testing of Variable Height Operating Characteristics of Super-Pressure Balloon Airbag Fan","authors":"Wei Qu, Qianghui Zhang, Yumei Qin, Jinggang Miao, Zeqing He, Yanchu Yang","doi":"10.3390/aerospace11010038","DOIUrl":"https://doi.org/10.3390/aerospace11010038","url":null,"abstract":"A fan is part of the core equipment of a super-pressure balloon altitude control system, and high-performance fans have a significant impact on the altitude control capability and flight safety of super-pressure balloons. This paper proposes a mixed-flow MIX-140 fan for use with super-pressure balloons. Changes in the fan’s operating characteristics at various flight altitudes of a super-pressure balloon were investigated. First, the performance of the fan at ground level was obtained through numerical simulation and compared with measured data of the prototype to verify the accuracy of the simulation analysis. On this basis, the influences of changes in the atmospheric pressure, temperature, and fan speed on fan performance were investigated through numerical simulation. Furthermore, the MIX-140 fan was compared with an existing fan, and the variation of two parameters, namely, the ratio of inflation volume per unit time and the ratio of inflation volume per unit power, were investigated at different altitudes. Finally, the changes in the operating characteristics of the fan under different high-altitude environments were investigated through actual testing. The results reveal that changes in altitude can lead to significant changes in fan performance, and changes in the atmospheric pressure, temperature, and fan speed affect the fan’s working characteristics. Compared with the existing fan, the MIX-140 fan achieves an average increase of 295.8% in the inflation volume per unit of time, and 14.6% in the inflation volume per unit of power at altitudes of 16–20 km. The performance variation characteristics and testing methods of this proposed super-pressure balloon fan can provide a foundation and reference for the design of a super-pressure balloon control system.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":" 9","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139145007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-28DOI: 10.3390/aerospace11010031
Arvid Åkerblom, Martin Passad, Alessandro Ercole, N. Zettervall, E. Nilsson, C. Fureby
With growing interest in sustainable civil supersonic and hypersonic aviation, there is a need to model the combustion of alternative, sustainable jet fuels. This work presents numerical simulations of several related phenomena, including laminar flames, ignition, and spray flames. Two conventional jet fuels, Jet A and JP-5, and two alternative jet fuels, C1 and C5, are targeted. The laminar burning velocities of these fuels are predicted using skeletal and detailed reaction mechanisms. The ignition delay times are predicted in the context of dual-mode ramjet engines. Large Eddy Simulations (LES) of spray combustion in an aeroengine are carried out to investigate how the different thermodynamic and chemical properties of alternative fuels lead to different emergent behavior. A novel set of thermodynamic correlations are developed for the spray model. The laminar burning velocity predictions are normalized by heat of combustion to reveal a more distinct fuel trend, with C1 burning slowest and C5 fastest. The ignition results highlight the contributions of the Negative Temperature Coefficient (NTC) effect, equivalence ratio, and hydrogen enrichment in determining ignition time scales in dual-mode ramjet engines. The spray results reveal that the volatile alternative jet fuels have short penetration depths and that the flame of the most chemically divergent fuel (C1) stabilizes relatively close to the spray.
随着人们对可持续民用超音速和高超音速航空的兴趣与日俱增，有必要建立可持续替代喷气燃料的燃烧模型。本研究对层流火焰、点火和喷射火焰等几种相关现象进行了数值模拟。模拟对象包括两种传统喷气燃料--喷气 A 和 JP-5，以及两种替代喷气燃料--C1 和 C5。这些燃料的层燃速度是通过骨架和详细反应机制预测的。在双模式冲压式喷气发动机的背景下预测了点火延迟时间。对航空发动机中的喷雾燃烧进行了大涡流模拟（LES），以研究替代燃料的不同热力学和化学特性如何导致不同的突发行为。为喷雾模型开发了一套新的热力学相关性。层流燃烧速度预测按燃烧热归一化，以揭示更明显的燃料趋势，其中 C1 燃烧速度最慢，C5 燃烧速度最快。点火结果凸显了负温度系数（NTC）效应、等效比和氢气富集在决定双模式冲压式喷气发动机点火时间尺度方面的作用。喷射结果表明，挥发性替代喷气燃料的穿透深度较短，化学性质最不相同的燃料（C1）的火焰在相对靠近喷射点的位置趋于稳定。
{"title":"Numerical Modeling of Chemical Kinetics, Spray Dynamics, and Turbulent Combustion towards Sustainable Aviation","authors":"Arvid Åkerblom, Martin Passad, Alessandro Ercole, N. Zettervall, E. Nilsson, C. Fureby","doi":"10.3390/aerospace11010031","DOIUrl":"https://doi.org/10.3390/aerospace11010031","url":null,"abstract":"With growing interest in sustainable civil supersonic and hypersonic aviation, there is a need to model the combustion of alternative, sustainable jet fuels. This work presents numerical simulations of several related phenomena, including laminar flames, ignition, and spray flames. Two conventional jet fuels, Jet A and JP-5, and two alternative jet fuels, C1 and C5, are targeted. The laminar burning velocities of these fuels are predicted using skeletal and detailed reaction mechanisms. The ignition delay times are predicted in the context of dual-mode ramjet engines. Large Eddy Simulations (LES) of spray combustion in an aeroengine are carried out to investigate how the different thermodynamic and chemical properties of alternative fuels lead to different emergent behavior. A novel set of thermodynamic correlations are developed for the spray model. The laminar burning velocity predictions are normalized by heat of combustion to reveal a more distinct fuel trend, with C1 burning slowest and C5 fastest. The ignition results highlight the contributions of the Negative Temperature Coefficient (NTC) effect, equivalence ratio, and hydrogen enrichment in determining ignition time scales in dual-mode ramjet engines. The spray results reveal that the volatile alternative jet fuels have short penetration depths and that the flame of the most chemically divergent fuel (C1) stabilizes relatively close to the spray.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"30 5","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139149725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-28DOI: 10.3390/aerospace11010029
Shiyan Lin, Ruiyu Li, Limin Gao, Ning Ge
The accurate prediction of tip leakage flow is the premise for flow mechanism analysis and compressor performance optimization. The detached eddy simulation (DES) method, which compromises cost and accuracy, has excellent potential for a high Reynolds flow, like a compressor.However, in the case of tip leakage flow, especially when there are multiple wall boundary layers and strong shear between the mainstream and leakage flow, the DES method exhibits accuracy deficiencies. This paper explores the resolution of the critical detailed structures using the DES method and its correlation with the accuracy of time-averaged aerodynamic parameter predictions. Based on this, we propose the necessary conditions for the DES method to accurately predict the leakage flow from the perspective of the detailed structure of the flow field. A simplified model is proposed to emphasize the characteristics of tip leakage flow with “multiple walls + narrow tip gap”, and the high-fidelity flow field of the WALE LES method is used as a benchmark. With the main fluctuation structures obtained by the SPOD method, it is concluded that the DES method is unable to resolve the Kelvin–Helmholtz instability at the initial position of the leakage, which leads to the generation of the secondary leakage vortex upstream of the leakage and the breakdown of the induced vortex, two critical flow structures, being incorrectly estimated. This can lead to misestimationsof the force direction on the tip leakage vortex and the main fluctuation on the flow field. As a result, the tip leakage vortex trajectory evolves toward the middle of the passage along the tangential direction and away from the upper wall downstream of the leakage compared with the LES results. Predictions of losses in the upstream and midstream regions are underestimated, whereas they are overestimated downstream of the leakage and outside the passage.Therefore, the accurate resolution of these two critical detailed structures is an essential prerequisite for the precise prediction of tip leakage flow using DES series methods.
尖端泄漏流的准确预测是流动机理分析和压缩机性能优化的前提。分离涡流模拟（DES）方法在成本和精度之间做出了妥协，但对于压缩机等高雷诺数流动具有很好的潜力。然而，在尖端泄漏流的情况下，特别是当存在多个壁面边界层以及主流和泄漏流之间存在强剪切力时，DES方法表现出精度缺陷。本文探讨了使用 DES 方法对关键细节结构的分辨率及其与时间平均气动参数预测精度的相关性。在此基础上，我们从流场细节结构的角度提出了 DES 方法准确预测泄漏流的必要条件。针对 "多壁+窄顶隙 "的尖端泄漏流特点，提出了一个简化模型，并以 WALE LES 方法的高保真流场为基准。通过 SPOD 方法得到的主要波动结构，得出 DES 方法无法解决泄漏初始位置的开尔文-赫尔姆霍兹不稳定性，导致泄漏上游次级泄漏涡的产生和诱导涡的破坏这两个关键流动结构被错误估计。这会导致对尖端泄漏漩涡受力方向和流场主要波动的错误估计。因此，与 LES 结果相比，尖端泄漏漩涡轨迹沿切线方向向通道中部演变，并远离泄漏下游的上壁。对上游和中游区域损失的预测被低估了，而对泄漏下游和通道外损失的预测则被高估了。因此，这两个关键细节结构的精确解析是使用 DES 系列方法精确预测尖端泄漏流的必要前提。
{"title":"Accuracy Investigations of Dynamic Characteristic Predictions of Tip Leakage Flow Using Detached Eddy Simulation","authors":"Shiyan Lin, Ruiyu Li, Limin Gao, Ning Ge","doi":"10.3390/aerospace11010029","DOIUrl":"https://doi.org/10.3390/aerospace11010029","url":null,"abstract":"The accurate prediction of tip leakage flow is the premise for flow mechanism analysis and compressor performance optimization. The detached eddy simulation (DES) method, which compromises cost and accuracy, has excellent potential for a high Reynolds flow, like a compressor.However, in the case of tip leakage flow, especially when there are multiple wall boundary layers and strong shear between the mainstream and leakage flow, the DES method exhibits accuracy deficiencies. This paper explores the resolution of the critical detailed structures using the DES method and its correlation with the accuracy of time-averaged aerodynamic parameter predictions. Based on this, we propose the necessary conditions for the DES method to accurately predict the leakage flow from the perspective of the detailed structure of the flow field. A simplified model is proposed to emphasize the characteristics of tip leakage flow with “multiple walls + narrow tip gap”, and the high-fidelity flow field of the WALE LES method is used as a benchmark. With the main fluctuation structures obtained by the SPOD method, it is concluded that the DES method is unable to resolve the Kelvin–Helmholtz instability at the initial position of the leakage, which leads to the generation of the secondary leakage vortex upstream of the leakage and the breakdown of the induced vortex, two critical flow structures, being incorrectly estimated. This can lead to misestimationsof the force direction on the tip leakage vortex and the main fluctuation on the flow field. As a result, the tip leakage vortex trajectory evolves toward the middle of the passage along the tangential direction and away from the upper wall downstream of the leakage compared with the LES results. Predictions of losses in the upstream and midstream regions are underestimated, whereas they are overestimated downstream of the leakage and outside the passage.Therefore, the accurate resolution of these two critical detailed structures is an essential prerequisite for the precise prediction of tip leakage flow using DES series methods.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"8 4p2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139150847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-28DOI: 10.3390/aerospace11010028
Zhou Shen, Beimeng Hu, Guozhan Li, Hongjun Zhang
The effects of the coolant pulsation and the plasma aerodynamic actuation (PAA) on the film cooling are herein explored via large eddy simulations. The electrohydrodynamic force derived from the PAA was solved through the phenomenological plasma model. The Strouhal number of the sinusoidal coolant pulsation and the averaged pulsation blowing ratio were 0.25 and 1.0, respectively. Comprehensive analyses were carried out on the time-averaged flow fields, and the results reveal that the pulsed cooling jet might cause a deeper penetration into the crossflow, and this phenomenon could be remarkably mitigated by the downward force of the PAA. Comparing steady film cooling to pulsed film cooling revealed a modest 15.1% reduction in efficiency, while the application of the dielectric barrier discharge plasma actuator (DBDPA) substantially enhanced the pulsed film cooling efficiency by 42.1%. Moreover, the counter-rotating vortex pair (CRVP) was enlarged and lifted off from the wall more poorly due to the coolant pulsation, and the PAA weakened the detrimental lift-off effect and entrainment of the CRVP. Then, the spatial–temporal development of the coherent structures was figured out by the alterations in the centerline temperature, reflecting the formation of the intermittent coherent structures rather than hairpin vortices due to the coolant pulsation, and their size and upcast behaviors were reduced by the PAA; thus, the turbulent integration of the coolant with the crossflow was suppressed fundamentally. Finally, the three-dimensional streamlines confirmed that the coherent structure dynamic behaviors were significantly regulated by the PAA for alleviating the adverse influences of the coolant pulsation. In summary, the PAA can effectively improve the pulsed film cooling efficiency by controlling the spatial–temporal development of the dominant coherent structures.
{"title":"Large Eddy Simulation of Pulsed Film Cooling with a Dielectric Barrier Discharge Plasma Actuator","authors":"Zhou Shen, Beimeng Hu, Guozhan Li, Hongjun Zhang","doi":"10.3390/aerospace11010028","DOIUrl":"https://doi.org/10.3390/aerospace11010028","url":null,"abstract":"The effects of the coolant pulsation and the plasma aerodynamic actuation (PAA) on the film cooling are herein explored via large eddy simulations. The electrohydrodynamic force derived from the PAA was solved through the phenomenological plasma model. The Strouhal number of the sinusoidal coolant pulsation and the averaged pulsation blowing ratio were 0.25 and 1.0, respectively. Comprehensive analyses were carried out on the time-averaged flow fields, and the results reveal that the pulsed cooling jet might cause a deeper penetration into the crossflow, and this phenomenon could be remarkably mitigated by the downward force of the PAA. Comparing steady film cooling to pulsed film cooling revealed a modest 15.1% reduction in efficiency, while the application of the dielectric barrier discharge plasma actuator (DBDPA) substantially enhanced the pulsed film cooling efficiency by 42.1%. Moreover, the counter-rotating vortex pair (CRVP) was enlarged and lifted off from the wall more poorly due to the coolant pulsation, and the PAA weakened the detrimental lift-off effect and entrainment of the CRVP. Then, the spatial–temporal development of the coherent structures was figured out by the alterations in the centerline temperature, reflecting the formation of the intermittent coherent structures rather than hairpin vortices due to the coolant pulsation, and their size and upcast behaviors were reduced by the PAA; thus, the turbulent integration of the coolant with the crossflow was suppressed fundamentally. Finally, the three-dimensional streamlines confirmed that the coherent structure dynamic behaviors were significantly regulated by the PAA for alleviating the adverse influences of the coolant pulsation. In summary, the PAA can effectively improve the pulsed film cooling efficiency by controlling the spatial–temporal development of the dominant coherent structures.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"131 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139149178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-28DOI: 10.3390/aerospace11010030
M. Zamarreño Suárez, Juan Marín Martínez, F. Pérez Moreno, Raquel Delgado-Aguilera Jurado, Patricia María López de Frutos, R. A. Arnaldo Valdés
The use of electroencephalography (EEG) techniques has many advantages in the study of human performance in air traffic control (ATC). At present, these are non-intrusive techniques that allow large volumes of data to be recorded on a continuous basis using wireless equipment. To achieve the most with these techniques, it is essential to establish appropriate EEG parameters with a clear understanding of the process followed to obtain them and their practical application. This study explains, step by step, the approach adopted to obtain six EEG parameters: excitement, stress, boredom, relaxation, engagement, and attention. It then explains all the steps involved in analysing the relationship between these parameters and two other parameters that characterise the state of the air traffic control sector during the development of real-time simulations (RTS): taskload and number of simultaneous aircraft. For this case study, the results showed the highest relationships for the engagement and attention parameters. In general, the results confirmed the potential of using these EEG parameters.
{"title":"From Raw Data to Practical Application: EEG Parameters for Human Performance Studies in Air Traffic Control","authors":"M. Zamarreño Suárez, Juan Marín Martínez, F. Pérez Moreno, Raquel Delgado-Aguilera Jurado, Patricia María López de Frutos, R. A. Arnaldo Valdés","doi":"10.3390/aerospace11010030","DOIUrl":"https://doi.org/10.3390/aerospace11010030","url":null,"abstract":"The use of electroencephalography (EEG) techniques has many advantages in the study of human performance in air traffic control (ATC). At present, these are non-intrusive techniques that allow large volumes of data to be recorded on a continuous basis using wireless equipment. To achieve the most with these techniques, it is essential to establish appropriate EEG parameters with a clear understanding of the process followed to obtain them and their practical application. This study explains, step by step, the approach adopted to obtain six EEG parameters: excitement, stress, boredom, relaxation, engagement, and attention. It then explains all the steps involved in analysing the relationship between these parameters and two other parameters that characterise the state of the air traffic control sector during the development of real-time simulations (RTS): taskload and number of simultaneous aircraft. For this case study, the results showed the highest relationships for the engagement and attention parameters. In general, the results confirmed the potential of using these EEG parameters.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"288 8‐9","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139152722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-27DOI: 10.3390/aerospace11010027
Bocheng Zhao, M. Huo, Ze Yu, Naiming Qi, Jianfeng Wang
In this study, we propose an aerial rendezvous method to facilitate the recovery of unmanned aerial vehicles (UAVs) using carrier aircrafts, which is an important capability for the future use of UAVs. The main contribution of this study is the development of a promising method for online generation of feasible rendezvous trajectories for UAVs. First, the wake vortex of a carrier aircraft is analyzed using the finite element method, and a method for establishing a safety constraint model is proposed. Subsequently, a model-reference reinforcementearning algorithm is proposed based on the potential function method, which can ensure the convergence and stability of training. A combined reward function is designed to solve the UAV trajectory generation problem under non-convex constraints. The simulation results show that, compared with the traditional artificial potential field method under different working conditions, the success rate of this method under non-convex constraints is close to 100%, with high accuracy, convergence, and stability, and has greater application potential in the aerial recovery scenario, providing a solution to the trajectory generation problem of UAVs under non-convex constraints.
{"title":"Model-Reference Reinforcement Learning for Safe Aerial Recovery of Unmanned Aerial Vehicles","authors":"Bocheng Zhao, M. Huo, Ze Yu, Naiming Qi, Jianfeng Wang","doi":"10.3390/aerospace11010027","DOIUrl":"https://doi.org/10.3390/aerospace11010027","url":null,"abstract":"In this study, we propose an aerial rendezvous method to facilitate the recovery of unmanned aerial vehicles (UAVs) using carrier aircrafts, which is an important capability for the future use of UAVs. The main contribution of this study is the development of a promising method for online generation of feasible rendezvous trajectories for UAVs. First, the wake vortex of a carrier aircraft is analyzed using the finite element method, and a method for establishing a safety constraint model is proposed. Subsequently, a model-reference reinforcementearning algorithm is proposed based on the potential function method, which can ensure the convergence and stability of training. A combined reward function is designed to solve the UAV trajectory generation problem under non-convex constraints. The simulation results show that, compared with the traditional artificial potential field method under different working conditions, the success rate of this method under non-convex constraints is close to 100%, with high accuracy, convergence, and stability, and has greater application potential in the aerial recovery scenario, providing a solution to the trajectory generation problem of UAVs under non-convex constraints.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"162 6","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139153808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-26DOI: 10.3390/aerospace11010022
Sergios Villette, Dimitris Adam, A. Alexiou, N. Aretakis, K. Mathioudakis
In a time when low emission solutions and technologies are of utmost importance regarding the sustainability of the aviation sector, this publication introduces a reduced-order physics-based model for combustion chambers of aeroengines, which is capable of reliably producing accurate pollutant emission and combustion efficiency estimations. The burner is subdivided into three volumes, with each represented by a single perfectly stirred reactor, thereby resulting in a simplified three-element serial chemical reactor network configuration, reducing complexity, and promoting the generality and ease of use of the model, without requiring the proprietary engine information needed by other such models. A tuning method is proposed to circumvent the limitations of its simplified configuration and the lack of detailed geometric data for combustors in literature. In contrast to most similar frameworks, this also provides the model with the ability to simultaneously predict the combustion efficiency and all pollutant emissions of interest (NOx, CO and unburnt hydrocarbons) more effectively by means of implementing a detailed chemical kinetics model. Validation against three correlation methods and actual aeroengine configurations demonstrates accurate performance and emission trend predictions. Integrated within two distinct combustion chamber low-emission preliminary design processes, the proposed model evaluates each new design, thereby displaying the ability to be employed in terms of optimizing a combustor’s overall performance given its sensitivity to geometric changes. Overall, the proposed model proves its worth as a reliable and valuable tool for use towards a greener future in aviation.
{"title":"A Simplified Chemical Reactor Network Approach for Aeroengine Combustion Chamber Modeling and Preliminary Design","authors":"Sergios Villette, Dimitris Adam, A. Alexiou, N. Aretakis, K. Mathioudakis","doi":"10.3390/aerospace11010022","DOIUrl":"https://doi.org/10.3390/aerospace11010022","url":null,"abstract":"In a time when low emission solutions and technologies are of utmost importance regarding the sustainability of the aviation sector, this publication introduces a reduced-order physics-based model for combustion chambers of aeroengines, which is capable of reliably producing accurate pollutant emission and combustion efficiency estimations. The burner is subdivided into three volumes, with each represented by a single perfectly stirred reactor, thereby resulting in a simplified three-element serial chemical reactor network configuration, reducing complexity, and promoting the generality and ease of use of the model, without requiring the proprietary engine information needed by other such models. A tuning method is proposed to circumvent the limitations of its simplified configuration and the lack of detailed geometric data for combustors in literature. In contrast to most similar frameworks, this also provides the model with the ability to simultaneously predict the combustion efficiency and all pollutant emissions of interest (NOx, CO and unburnt hydrocarbons) more effectively by means of implementing a detailed chemical kinetics model. Validation against three correlation methods and actual aeroengine configurations demonstrates accurate performance and emission trend predictions. Integrated within two distinct combustion chamber low-emission preliminary design processes, the proposed model evaluates each new design, thereby displaying the ability to be employed in terms of optimizing a combustor’s overall performance given its sensitivity to geometric changes. Overall, the proposed model proves its worth as a reliable and valuable tool for use towards a greener future in aviation.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"23 51","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139156120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-26DOI: 10.3390/aerospace11010021
Yucheng Yang, Guohua Xu, Yongjie Shi, Zhiyuan Hu
This study develops a hybrid solver with reversed overset assembly technology (ROAT), a viscous vortex particle method (VVPM), and a CFD program based on the URNS method, in order to study the aerodynamic and acoustic characteristics of coaxial rigid rotors. The aerodynamic load of the “AH-1G” helicopter rotor is first calculated based on the hybrid method and compared with available experimental data. The prediction of the linear noise of the OLS rotor is then performed and the obtained results are compared with available experimental data. These results allow the evaluation of the accuracy of the hybrid method for emulating rotor aerodynamics and acoustics. Afterwards, the hybrid and CFD methods are applied to obtain the aerodynamic and acoustic characteristics of the given coaxial rigid rotor model, while taking into account the trim of the collective pitch. The obtained results demonstrate that the hybrid method has high proficiency in capturing blade–vortex-interaction impulsive loads and high computational efficiency in predicting associated loading noise characteristics. Furthermore, the effect of the hybrid method on the noise characteristics of coaxial rigid rotors under a different advance ratio, blade tip speed, shaft angle, and other conditions, as well as the impact of the upper and lower rotors on the noise contribution of the coaxial rotor are analyzed. Finally, the impacts of the initial phase and the vertical spacing on the sound pressure level are studied.
{"title":"Analysis of the Aeroacoustic Characteristics of a Rigid Coaxial Rotor in Forward Flight Based on the CFD/VVPM Hybrid Method","authors":"Yucheng Yang, Guohua Xu, Yongjie Shi, Zhiyuan Hu","doi":"10.3390/aerospace11010021","DOIUrl":"https://doi.org/10.3390/aerospace11010021","url":null,"abstract":"This study develops a hybrid solver with reversed overset assembly technology (ROAT), a viscous vortex particle method (VVPM), and a CFD program based on the URNS method, in order to study the aerodynamic and acoustic characteristics of coaxial rigid rotors. The aerodynamic load of the “AH-1G” helicopter rotor is first calculated based on the hybrid method and compared with available experimental data. The prediction of the linear noise of the OLS rotor is then performed and the obtained results are compared with available experimental data. These results allow the evaluation of the accuracy of the hybrid method for emulating rotor aerodynamics and acoustics. Afterwards, the hybrid and CFD methods are applied to obtain the aerodynamic and acoustic characteristics of the given coaxial rigid rotor model, while taking into account the trim of the collective pitch. The obtained results demonstrate that the hybrid method has high proficiency in capturing blade–vortex-interaction impulsive loads and high computational efficiency in predicting associated loading noise characteristics. Furthermore, the effect of the hybrid method on the noise characteristics of coaxial rigid rotors under a different advance ratio, blade tip speed, shaft angle, and other conditions, as well as the impact of the upper and lower rotors on the noise contribution of the coaxial rotor are analyzed. Finally, the impacts of the initial phase and the vertical spacing on the sound pressure level are studied.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"13 15","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139156862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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