Pub Date : 2023-12-25DOI: 10.3390/aerospace11010020
Long Li, Yiming Peng, Yifeng Wang, Xiaohui Wei, Hong Nie
Arresting gear systems play a vital role in carrier-based aircraft landing. In order to accurately understand the process of arresting hook and cable, this study introduces a parameter inversion method to model the arresting cable and applies it to the transient dynamics model of the arresting hook and cable. The feasibility of the arresting cable model and its application to the transient dynamics model of the arresting hook and cable are validated through arresting hook and cable impact tests. The study compares three different models of arresting cables for simulation results and concludes that assuming the arresting cable to be a beam with metal elastic parameters during the modeling process cannot ignore the influence of the cable’s torsional and bending stiffness on the modeling. The study also investigates the dynamic response of the arresting hook during the aircraft arrestment and hooking process and concludes that the stress peak of the hook arm is much lower throughout the entire arrestment process than at the moment of hooking the cable. The study further identifies factors that affect the stress on the arresting hook arm, such as the aircraft’s yaw angle, deck angle, cruising speed, and the initial position of the arresting hook and cable before engagement. The research results have significant implications for improving the design optimization of the structural strength of the functional components of the naval aircraft arresting system and provide theoretical guidance and technical reserves for subsequent related studies.
{"title":"Modeling the Transient Dynamics of Arresting Hooks and Cables through the Parameter Inversion Method","authors":"Long Li, Yiming Peng, Yifeng Wang, Xiaohui Wei, Hong Nie","doi":"10.3390/aerospace11010020","DOIUrl":"https://doi.org/10.3390/aerospace11010020","url":null,"abstract":"Arresting gear systems play a vital role in carrier-based aircraft landing. In order to accurately understand the process of arresting hook and cable, this study introduces a parameter inversion method to model the arresting cable and applies it to the transient dynamics model of the arresting hook and cable. The feasibility of the arresting cable model and its application to the transient dynamics model of the arresting hook and cable are validated through arresting hook and cable impact tests. The study compares three different models of arresting cables for simulation results and concludes that assuming the arresting cable to be a beam with metal elastic parameters during the modeling process cannot ignore the influence of the cable’s torsional and bending stiffness on the modeling. The study also investigates the dynamic response of the arresting hook during the aircraft arrestment and hooking process and concludes that the stress peak of the hook arm is much lower throughout the entire arrestment process than at the moment of hooking the cable. The study further identifies factors that affect the stress on the arresting hook arm, such as the aircraft’s yaw angle, deck angle, cruising speed, and the initial position of the arresting hook and cable before engagement. The research results have significant implications for improving the design optimization of the structural strength of the functional components of the naval aircraft arresting system and provide theoretical guidance and technical reserves for subsequent related studies.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"31 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139159347","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 : 2023-12-25DOI: 10.3390/aerospace11010019
Thomas Rötger, Chris Eyers, Roberta Fusaro
The request for faster and greener civil aviation is urging the worldwide scientific community and aerospace industry to develop a new generation of supersonic aircraft, which are expected to be environmentally sustainable, and to guarantee a high level of protection for citizens. The availability of novel propulsive technologies, together with the development of new civil supersonic passenger aircraft configurations and missions, is pushing international authorities to update the regulatory framework to limit nuisances on the ground and the contribution to climate change. Existing ICAO noise and emissions standards are outdated as they were developed in the 1970s and tailored to Concorde, the only SST that has ever operated in Western airspace. This article provides (i) a comprehensive review of current environmental regulations for SST, encompassing noise and pollutant emissions near airports (LTO cycle) as well as CO2 emissions and sonic booms, and (ii) updated information about the ongoing rulemaking activities by ICAO, FAA and EASA. This review clearly highlights the following findings: (i) the need to revise current rules to better fit future SST design, operations and technologies; (ii) the need to introduce new regulations to cover additional aspects, including stratospheric water vapour emissions and ozone depletion; and (iii) the need to support regulatory activities with solid technical bases, fostering cooperation with academia, research centres and industry in R&D projects. Eventually, a practical example of how SST rulemaking activities are supported by the collaborative research H2020 MORE&LESS is reported.
{"title":"A Review of the Current Regulatory Framework for Supersonic Civil Aircraft: Noise and Emissions Regulations","authors":"Thomas Rötger, Chris Eyers, Roberta Fusaro","doi":"10.3390/aerospace11010019","DOIUrl":"https://doi.org/10.3390/aerospace11010019","url":null,"abstract":"The request for faster and greener civil aviation is urging the worldwide scientific community and aerospace industry to develop a new generation of supersonic aircraft, which are expected to be environmentally sustainable, and to guarantee a high level of protection for citizens. The availability of novel propulsive technologies, together with the development of new civil supersonic passenger aircraft configurations and missions, is pushing international authorities to update the regulatory framework to limit nuisances on the ground and the contribution to climate change. Existing ICAO noise and emissions standards are outdated as they were developed in the 1970s and tailored to Concorde, the only SST that has ever operated in Western airspace. This article provides (i) a comprehensive review of current environmental regulations for SST, encompassing noise and pollutant emissions near airports (LTO cycle) as well as CO2 emissions and sonic booms, and (ii) updated information about the ongoing rulemaking activities by ICAO, FAA and EASA. This review clearly highlights the following findings: (i) the need to revise current rules to better fit future SST design, operations and technologies; (ii) the need to introduce new regulations to cover additional aspects, including stratospheric water vapour emissions and ozone depletion; and (iii) the need to support regulatory activities with solid technical bases, fostering cooperation with academia, research centres and industry in R&D projects. Eventually, a practical example of how SST rulemaking activities are supported by the collaborative research H2020 MORE&LESS is reported.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"46 6","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139158671","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 : 2023-12-24DOI: 10.3390/aerospace11010018
Changwu Liang, Hong Li, Taoyong Su, Caleb Alistair Frank, Kewei Li
An electrically controlled rotor (ECR), also known as a swashplateless rotor, eliminates the swashplate system to implement the primary control via the trailing-edge flaps (TEFs), which can result in enhancements in rotor performance, as well as substantial reductions in weight, drag, and cost. In this paper, the unsteady aerodynamic characteristics of the airfoil with TEF of a sample ECR under unsteady freestream condition are investigated. The CFD results are obtained with sliding and overset grid techniques that simulate the airfoil pitching and flap deflection. Comparative analysis of the aerodynamic characteristics under steady and unsteady freestream conditions at different advance ratios is conducted. At various advance ratios, the lift and drag coefficients are higher at a small angle of attack under unsteady freestream condition; however, it is the opposite at a large angle of attack. The peak values of the lift and drag coefficients show an increased trend with the increase in the advance ratio. On the contrary, the pitch moment and flap hinge moment coefficients demonstrate minor variation under unsteady freestream condition. Furthermore, the aerodynamic characteristics of airfoils become more unsteady with variation in the freestream. Therefore, the lift and drag coefficients of the ECR airfoil with TEF show significant differences between steady and unsteady freestream conditions; however, the pitch moment and the flap hinge moment coefficients show little difference.
{"title":"Research of Unsteady Aerodynamic Characteristics of Electrically Controlled Rotor Airfoils with Trailing-Edge Flaps","authors":"Changwu Liang, Hong Li, Taoyong Su, Caleb Alistair Frank, Kewei Li","doi":"10.3390/aerospace11010018","DOIUrl":"https://doi.org/10.3390/aerospace11010018","url":null,"abstract":"An electrically controlled rotor (ECR), also known as a swashplateless rotor, eliminates the swashplate system to implement the primary control via the trailing-edge flaps (TEFs), which can result in enhancements in rotor performance, as well as substantial reductions in weight, drag, and cost. In this paper, the unsteady aerodynamic characteristics of the airfoil with TEF of a sample ECR under unsteady freestream condition are investigated. The CFD results are obtained with sliding and overset grid techniques that simulate the airfoil pitching and flap deflection. Comparative analysis of the aerodynamic characteristics under steady and unsteady freestream conditions at different advance ratios is conducted. At various advance ratios, the lift and drag coefficients are higher at a small angle of attack under unsteady freestream condition; however, it is the opposite at a large angle of attack. The peak values of the lift and drag coefficients show an increased trend with the increase in the advance ratio. On the contrary, the pitch moment and flap hinge moment coefficients demonstrate minor variation under unsteady freestream condition. Furthermore, the aerodynamic characteristics of airfoils become more unsteady with variation in the freestream. Therefore, the lift and drag coefficients of the ECR airfoil with TEF show significant differences between steady and unsteady freestream conditions; however, the pitch moment and the flap hinge moment coefficients show little difference.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"558 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160693","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 : 2023-12-24DOI: 10.3390/aerospace11010017
Omkar Walvekar, Satyanarayanan Chakravarthy
A conceptual framework is presented to determine the improvement in the aerodynamic performance of a canard aircraft fitted with distributed propellers along its main wing. A preliminary study is described with four airframe–propeller configurations predominantly studied in academic and commercial designs. The leading edge–based tractors and trailing edge–based pushers are identified as configurations of interest for the main study. Subsequently, a Navier–Stokes solver is used to simulate the flow using two numerical approaches–a modified steady-state actuator disk and an unsteady rotating propeller profile. Moving meshes with rotating sub-domains are used with a hybrid RANS-LES-based turbulence model while the actuator disks are modified to include viscous swirl effects. The preliminary study shows a local minimum in the change in CL and CD at 10∘ for the pusher and tractor configurations. The main study then demonstrates the outperformance of the pushers over tractors quantified using CL and CL/CD. There is a clear preference for the pushers as they increase the lifting capacity of the aircraft without disproportionately increasing the drag due to the flow smoothening by the suction of the pusher propellers over the main wing. The pushers also delay the separation of the boundary layer whereas the tractors are unable to prevent the formation of the separation bubble despite injecting momentum through their slipstreams into the flow. The results from the two numerical approaches are then compared for accuracy in designing DEP configurations for an airframe.
本文提出了一个概念框架，以确定沿主翼安装分布式螺旋桨的鸭式飞机的气动性能改进情况。初步研究描述了在学术和商业设计中主要研究的四种机身-螺旋桨配置。基于前缘的牵引器和基于后缘的推进器被确定为主要研究的相关配置。随后，使用纳维-斯托克斯求解器，采用两种数值方法--改进的稳态致动器盘和非稳态旋转螺旋桨剖面--模拟流动。旋转子域的移动网格与基于 RANS-LES 的混合湍流模型一起使用，同时对致动器盘进行了修改，以包含粘性漩涡效应。初步研究表明，对于推杆和牵引器配置，CL 和 CD 的变化在 10∘处为局部最小值。随后的主要研究表明，使用 CL 和 CL/CD 量化推杆的性能优于拖拉机。由于推力螺旋桨在主翼上的吸力会使气流更加平滑，因此不会不成比例地增加阻力，从而提高了飞机的升力。推进器还能延迟边界层的分离，而牵引器尽管通过滑流向气流注入动量，却无法阻止分离气泡的形成。然后比较了两种数值方法的结果，以确定为机身设计 DEP 配置的准确性。
{"title":"An Unsteady Reynolds–Averaged Navier–Stokes–Large Eddy Simulation Study of Propeller–Airframe Interaction in Distributed Electric Propulsion","authors":"Omkar Walvekar, Satyanarayanan Chakravarthy","doi":"10.3390/aerospace11010017","DOIUrl":"https://doi.org/10.3390/aerospace11010017","url":null,"abstract":"A conceptual framework is presented to determine the improvement in the aerodynamic performance of a canard aircraft fitted with distributed propellers along its main wing. A preliminary study is described with four airframe–propeller configurations predominantly studied in academic and commercial designs. The leading edge–based tractors and trailing edge–based pushers are identified as configurations of interest for the main study. Subsequently, a Navier–Stokes solver is used to simulate the flow using two numerical approaches–a modified steady-state actuator disk and an unsteady rotating propeller profile. Moving meshes with rotating sub-domains are used with a hybrid RANS-LES-based turbulence model while the actuator disks are modified to include viscous swirl effects. The preliminary study shows a local minimum in the change in CL and CD at 10∘ for the pusher and tractor configurations. The main study then demonstrates the outperformance of the pushers over tractors quantified using CL and CL/CD. There is a clear preference for the pushers as they increase the lifting capacity of the aircraft without disproportionately increasing the drag due to the flow smoothening by the suction of the pusher propellers over the main wing. The pushers also delay the separation of the boundary layer whereas the tractors are unable to prevent the formation of the separation bubble despite injecting momentum through their slipstreams into the flow. The results from the two numerical approaches are then compared for accuracy in designing DEP configurations for an airframe.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"1974 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160546","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 : 2023-12-24DOI: 10.3390/aerospace11010015
Lin Xu, Shanxiu Ma, Zhiyuan Shen, Shiyu Huang, Ying Nan
In order to determine the fatigue state of air traffic controllers from air talk, an algorithm is proposed for discriminating the fatigue state of controllers based on applying multi-speech feature fusion to voice data using a Fuzzy Support Vector Machine (FSVM). To supplement the basis for discrimination, we also extracted eye-fatigue-state discrimination features based on Percentage of Eyelid Closure Duration (PERCLOS) eye data. To merge the two classes of discrimination results, a new controller fatigue-state evaluation index based on the entropy weight method is proposed, based on a decision-level fusion of fatigue discrimination results for speech and the eyes. The experimental results show that the fatigue-state recognition accuracy rate was 86.0% for the fatigue state evaluation index, which was 3.5% and 2.2%higher than those for speech and eye assessments, respectively. The comprehensive fatigue evaluation index provides important reference values for controller scheduling and mental-state evaluations.
{"title":"Analyzing Multi-Mode Fatigue Information from Speech and Gaze Data from Air Traffic Controllers","authors":"Lin Xu, Shanxiu Ma, Zhiyuan Shen, Shiyu Huang, Ying Nan","doi":"10.3390/aerospace11010015","DOIUrl":"https://doi.org/10.3390/aerospace11010015","url":null,"abstract":"In order to determine the fatigue state of air traffic controllers from air talk, an algorithm is proposed for discriminating the fatigue state of controllers based on applying multi-speech feature fusion to voice data using a Fuzzy Support Vector Machine (FSVM). To supplement the basis for discrimination, we also extracted eye-fatigue-state discrimination features based on Percentage of Eyelid Closure Duration (PERCLOS) eye data. To merge the two classes of discrimination results, a new controller fatigue-state evaluation index based on the entropy weight method is proposed, based on a decision-level fusion of fatigue discrimination results for speech and the eyes. The experimental results show that the fatigue-state recognition accuracy rate was 86.0% for the fatigue state evaluation index, which was 3.5% and 2.2%higher than those for speech and eye assessments, respectively. The comprehensive fatigue evaluation index provides important reference values for controller scheduling and mental-state evaluations.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"331 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160854","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 : 2023-12-24DOI: 10.3390/aerospace11010016
Farid Saemi, Moble Benedict
Minimizing electric losses is critical to the success of battery-powered small unmanned aerial systems (SUASs) that weigh less than 25 kgf (55 lb). Losses increase energy and battery weight requirements which hinder the vehicle’s range and endurance. However, engineers do not have appropriate models to estimate the losses of a motor, motor controller, or battery. The aerospace literature often assumes an ideal electrical efficiency or describes modeling approaches that are more suitable for controls engineers. The electrical literature describes detailed design tools that target the motor designer. We developed SUAS powertrain models targeted for vehicle designers and systems engineers. The analytical models predict each component’s losses using high-level specifications readily published in SUAS component datasheets. We validated the models against parametric experimental studies involving novel powertrain flight data from a specially instrumented quadcopter. Given propeller torque and speed, our integrated models predicted a quadcopter’s battery voltage within 5% of experimental data for a 5+ min mission despite motor and controller efficiency errors up to 10%. The models can reduce development costs and timelines for different stakeholders. Users can evaluate notional or existing powertrain configurations over entire missions without testing any physical hardware.
对于重量小于 25 千克重（55 磅）的电池供电小型无人驾驶航空系统（SUAS）来说，最大限度地减少电力损耗是成功的关键。损耗会增加对能量和电池重量的要求，从而影响飞行器的续航能力和耐用性。然而，工程师并没有合适的模型来估算电机、电机控制器或电池的损耗。航空航天文献通常假设理想的电气效率，或描述更适合控制工程师的建模方法。电气文献则介绍了针对电机设计师的详细设计工具。我们针对车辆设计师和系统工程师开发了 SUAS 动力总成模型。分析模型使用 SUAS 组件数据表中随时公布的高级规格来预测每个组件的损耗。我们根据参数实验研究验证了这些模型，实验研究涉及来自专门配备仪器的四旋翼飞行器的新型动力总成飞行数据。在给定螺旋桨扭矩和速度的情况下，尽管电机和控制器的效率误差高达 10%，但我们的集成模型对四旋翼飞行器电池电压的预测在 5 分钟以上飞行任务的实验数据的 5%以内。这些模型可以为不同的利益相关者降低开发成本，缩短开发时间。用户可以在不测试任何物理硬件的情况下，对整个飞行任务中的名义或现有动力总成配置进行评估。
{"title":"Flight-Validated Electric Powertrain Efficiency Models for Small UASs","authors":"Farid Saemi, Moble Benedict","doi":"10.3390/aerospace11010016","DOIUrl":"https://doi.org/10.3390/aerospace11010016","url":null,"abstract":"Minimizing electric losses is critical to the success of battery-powered small unmanned aerial systems (SUASs) that weigh less than 25 kgf (55 lb). Losses increase energy and battery weight requirements which hinder the vehicle’s range and endurance. However, engineers do not have appropriate models to estimate the losses of a motor, motor controller, or battery. The aerospace literature often assumes an ideal electrical efficiency or describes modeling approaches that are more suitable for controls engineers. The electrical literature describes detailed design tools that target the motor designer. We developed SUAS powertrain models targeted for vehicle designers and systems engineers. The analytical models predict each component’s losses using high-level specifications readily published in SUAS component datasheets. We validated the models against parametric experimental studies involving novel powertrain flight data from a specially instrumented quadcopter. Given propeller torque and speed, our integrated models predicted a quadcopter’s battery voltage within 5% of experimental data for a 5+ min mission despite motor and controller efficiency errors up to 10%. The models can reduce development costs and timelines for different stakeholders. Users can evaluate notional or existing powertrain configurations over entire missions without testing any physical hardware.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"1990 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139160461","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 : 2023-12-24DOI: 10.3390/aerospace11010014
Jan Jepkens, P. Müller, H. Wester, S. Hübner, Simon Wehrmann, Bernd-Arno Behrens
In the aviation industry, a large number of processes are not digitalised. Simultaneously, many special processes are used in production, such as incremental bending. In order to model and efficiently design multi-stage processes with methods such as FEM, automation and linking of the individual simulations are necessary. This paper therefore presents a method for automatically simulating and evaluating a complete incremental bending process with 24 strokes in LS-Dyna using a Python framework with cfiles. The final validation of the force–displacement relationships and inner radii of the generated scaled fuselage shell show high prediction accuracies of about 90%. Thus, the presented methodology enables a FEM-based process design of incremental bending in the aviation industry.
{"title":"Simulation and Validation of an Incremental Bending Process for Cylindrical Fuselage Components","authors":"Jan Jepkens, P. Müller, H. Wester, S. Hübner, Simon Wehrmann, Bernd-Arno Behrens","doi":"10.3390/aerospace11010014","DOIUrl":"https://doi.org/10.3390/aerospace11010014","url":null,"abstract":"In the aviation industry, a large number of processes are not digitalised. Simultaneously, many special processes are used in production, such as incremental bending. In order to model and efficiently design multi-stage processes with methods such as FEM, automation and linking of the individual simulations are necessary. This paper therefore presents a method for automatically simulating and evaluating a complete incremental bending process with 24 strokes in LS-Dyna using a Python framework with cfiles. The final validation of the force–displacement relationships and inner radii of the generated scaled fuselage shell show high prediction accuracies of about 90%. Thus, the presented methodology enables a FEM-based process design of incremental bending in the aviation industry.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"257 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139161089","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 : 2023-12-23DOI: 10.3390/aerospace11010013
Chunjie Zheng, Haitao Wang, Lanxiang Hu, Yuanli Cai
To study the hose-and-drogue system’s motion under bow waves, this paper established a dynamic model of the hose-and-drogue system based on the multibody dynamics theory and the rigid ball-and-rod model. The wake of a tanker aircraft was taken into account in the simulation. The simulation results conformed to the general laws and verified the model’s accuracy. The equilibrium positions of the hose-and-drogue system were computed by the linear superposition of the bow waves and wake. The motion of the hose-and-drogue system was simulated and analyzed when a receiver aircraft moved at a constant speed or accelerated relative to the tanker aircraft. Since the receiver aircraft would not immediately stop after docking, the pulling force changes on the hose with and without a reel were compared. The present results are essential for improving the success rate of aerial refueling and ensuring the safety and stability of the hose-and-drogue system.
{"title":"Research on the Motion and Dynamic Characteristics of the Hose-and-Drogue System under Bow Wave","authors":"Chunjie Zheng, Haitao Wang, Lanxiang Hu, Yuanli Cai","doi":"10.3390/aerospace11010013","DOIUrl":"https://doi.org/10.3390/aerospace11010013","url":null,"abstract":"To study the hose-and-drogue system’s motion under bow waves, this paper established a dynamic model of the hose-and-drogue system based on the multibody dynamics theory and the rigid ball-and-rod model. The wake of a tanker aircraft was taken into account in the simulation. The simulation results conformed to the general laws and verified the model’s accuracy. The equilibrium positions of the hose-and-drogue system were computed by the linear superposition of the bow waves and wake. The motion of the hose-and-drogue system was simulated and analyzed when a receiver aircraft moved at a constant speed or accelerated relative to the tanker aircraft. Since the receiver aircraft would not immediately stop after docking, the pulling force changes on the hose with and without a reel were compared. The present results are essential for improving the success rate of aerial refueling and ensuring the safety and stability of the hose-and-drogue system.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"189 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139163082","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 : 2023-12-22DOI: 10.3390/aerospace11010012
Giacomo Cinieri, Zubair Ali Shah, Guido Marseglia, M. D. De Giorgi
The research effort in the microcombustor field has recently increased due to the demand for high-performance systems in microelectromechanical and micro power generation devices. To address rising concerns about pollutants from fossil sources, zero-carbon fuels such as hydrogen (H2) and ammonia (NH3) have been considered as an alternative in microcombustion processes. In a microcombustor, the surface area-to-volume ratio is much higher compared to conventional combustion systems, resulting in faster heat transfer rates and more intense combustion reactions. However, achieving efficient mixing of fuel and an oxidizer in a microcombustor can be challenging due to its small size, particularly for highly reactive fuels like H2. For NH3, challenges in microcombustion involve a low reactive, high ignition temperature (923 K vs. 793 K of H2) and high concentration of NOx combustion products. Therefore, studying the performance of these fuels in microcombustors is important for developing clean energy technologies. In this paper, to explore features of non-premixed NH3/air and H2/air combustion in micro-scale combustors, an Ansys Fluent numerical investigation was conducted on a Y-shaped microcombustor. Results show that for combustion with H2, stationary flames can be achieved even at lower equivalence ratios. Additionally, the pollutants generated from H2 in the flame are generally twice those of NH3. The overall efficiency of the microcombustor is two times greater for NH3 conditions than for H2 conditions.
{"title":"Toward Zero Carbon Emissions: Investigating the Combustion Performance of Shaped Microcombustors Using H2/Air and NH3/Air Mixtures","authors":"Giacomo Cinieri, Zubair Ali Shah, Guido Marseglia, M. D. De Giorgi","doi":"10.3390/aerospace11010012","DOIUrl":"https://doi.org/10.3390/aerospace11010012","url":null,"abstract":"The research effort in the microcombustor field has recently increased due to the demand for high-performance systems in microelectromechanical and micro power generation devices. To address rising concerns about pollutants from fossil sources, zero-carbon fuels such as hydrogen (H2) and ammonia (NH3) have been considered as an alternative in microcombustion processes. In a microcombustor, the surface area-to-volume ratio is much higher compared to conventional combustion systems, resulting in faster heat transfer rates and more intense combustion reactions. However, achieving efficient mixing of fuel and an oxidizer in a microcombustor can be challenging due to its small size, particularly for highly reactive fuels like H2. For NH3, challenges in microcombustion involve a low reactive, high ignition temperature (923 K vs. 793 K of H2) and high concentration of NOx combustion products. Therefore, studying the performance of these fuels in microcombustors is important for developing clean energy technologies. In this paper, to explore features of non-premixed NH3/air and H2/air combustion in micro-scale combustors, an Ansys Fluent numerical investigation was conducted on a Y-shaped microcombustor. Results show that for combustion with H2, stationary flames can be achieved even at lower equivalence ratios. Additionally, the pollutants generated from H2 in the flame are generally twice those of NH3. The overall efficiency of the microcombustor is two times greater for NH3 conditions than for H2 conditions.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"60 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138945911","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 : 2023-12-22DOI: 10.3390/aerospace11010011
Eri Itoh, Koji Tominaga, Michael Schultz, Vu N. Duong
Free route airspace allows airspace users to freely plan a route in en-route airspaces within certain restrictions. It is anticipated to offer the benefit of fuel saving and operational flexibility. Regarding its efficient implementation into the ASEAN airspace, the key challenge would be reducing hotspots with clusters of potential conflicts. This paper designed a time-varying queuing network model, which contributed to untangle trajectory complexity in the most congested hotspot area. A series of fast-time simulation experiments were conducted to identify hotspots in en-route airspace in Singapore FIR. The application of departure time control using time-varying queuing networks successfully reduced up to 45% of potential conflicts. This was achieved within an average delay of 30 min by controlling time of less than 60% of candidate flights. The original contribution of this paper is to develop a novel modeling and simulation framework for composing ideal air traffic patterns. Lastly, we discussed the extension of this study toward a generalized application of the proposed approach in future air traffic management.
{"title":"Untangling Complexity in ASEAN Air Traffic Management through Time-Varying Queuing Models","authors":"Eri Itoh, Koji Tominaga, Michael Schultz, Vu N. Duong","doi":"10.3390/aerospace11010011","DOIUrl":"https://doi.org/10.3390/aerospace11010011","url":null,"abstract":"Free route airspace allows airspace users to freely plan a route in en-route airspaces within certain restrictions. It is anticipated to offer the benefit of fuel saving and operational flexibility. Regarding its efficient implementation into the ASEAN airspace, the key challenge would be reducing hotspots with clusters of potential conflicts. This paper designed a time-varying queuing network model, which contributed to untangle trajectory complexity in the most congested hotspot area. A series of fast-time simulation experiments were conducted to identify hotspots in en-route airspace in Singapore FIR. The application of departure time control using time-varying queuing networks successfully reduced up to 45% of potential conflicts. This was achieved within an average delay of 30 min by controlling time of less than 60% of candidate flights. The original contribution of this paper is to develop a novel modeling and simulation framework for composing ideal air traffic patterns. Lastly, we discussed the extension of this study toward a generalized application of the proposed approach in future air traffic management.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":"5 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944639","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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