Aerospace Science and Technology最新文献_第10页

Analysis of geometrical parameter sensitivity and mechanism of flow loss in exhaust volute based on particle swarm optimization

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109803

Dongliang Sun , Xiaolong Tang , Xiaoquan Yang , Jue Ding , Peifen Weng

To investigated the mechanism of flow loss occurs in gas-turbine exhaust volute, comprehensive analysis was conducted based on the traces of parametric optimizations. An original volute was parameterized by depicting the core-part with 6 parameters. Concerning the coefficients of total pressure loss and static pressure recovery, the volute was optimized, as a start of the investigation, by Particle Swarm Optimization (PSO) to generate 56 exhaust volute designs and 8 geometric parameter traces. The geometry evolution history was fully recorded by these traces during the optimization. Based on this, parameter sensitivity analyses were conducted by single, double and K-means-clustering-based comprehensive parameters. Furthermore, partial dependence plot (PDP) and individual conditional expectation plot (ICEP) were applied to enhance the expression of parameter sensitivity. This enables the detailed discussion of the mechanisms of flow loss occurs in exhaust volute. The results demonstrate that the Particle Swarm Optimization (PSO) algorithm is highly effective for optimizing the exhaust volute. After six rounds of optimization with eight particles per round, the total pressure loss coefficient at the exhaust volute outlet was reduced by 35%, while the static pressure recovery coefficient increased by 79%. The sensitivity analysis reveals that geometric parameters exhibit varying degrees of influence on aerodynamic performance, with diffuser length being the most critical factor. Notably, a shorter diffuser, constrained by the same external dimensions, tends to result in lower flow losses. Flow loss within the collector accounts for 71.7% of the total loss, which can be attributed to surface friction and turbulent dissipation. The latter is primarily driven by turbulent viscous dissipation, predominantly occurring in the collector section. Additionally, the size of large-scale vortices in the curved parts of the diffuser and collector, which contribute to turbulent dissipation, as well as the ratio of the average flow velocity to circulation speed in the collector, which affects wall friction, are key factors in flow loss generation.

{"title":"Analysis of geometrical parameter sensitivity and mechanism of flow loss in exhaust volute based on particle swarm optimization","authors":"Dongliang Sun , Xiaolong Tang , Xiaoquan Yang , Jue Ding , Peifen Weng","doi":"10.1016/j.ast.2024.109803","DOIUrl":"10.1016/j.ast.2024.109803","url":null,"abstract":"<div><div>To investigated the mechanism of flow loss occurs in gas-turbine exhaust volute, comprehensive analysis was conducted based on the traces of parametric optimizations. An original volute was parameterized by depicting the core-part with 6 parameters. Concerning the coefficients of total pressure loss and static pressure recovery, the volute was optimized, as a start of the investigation, by Particle Swarm Optimization (PSO) to generate 56 exhaust volute designs and 8 geometric parameter traces. The geometry evolution history was fully recorded by these traces during the optimization. Based on this, parameter sensitivity analyses were conducted by single, double and K-means-clustering-based comprehensive parameters. Furthermore, partial dependence plot (PDP) and individual conditional expectation plot (ICEP) were applied to enhance the expression of parameter sensitivity. This enables the detailed discussion of the mechanisms of flow loss occurs in exhaust volute. The results demonstrate that the Particle Swarm Optimization (PSO) algorithm is highly effective for optimizing the exhaust volute. After six rounds of optimization with eight particles per round, the total pressure loss coefficient at the exhaust volute outlet was reduced by 35%, while the static pressure recovery coefficient increased by 79%. The sensitivity analysis reveals that geometric parameters exhibit varying degrees of influence on aerodynamic performance, with diffuser length being the most critical factor. Notably, a shorter diffuser, constrained by the same external dimensions, tends to result in lower flow losses. Flow loss within the collector accounts for 71.7% of the total loss, which can be attributed to surface friction and turbulent dissipation. The latter is primarily driven by turbulent viscous dissipation, predominantly occurring in the collector section. Additionally, the size of large-scale vortices in the curved parts of the diffuser and collector, which contribute to turbulent dissipation, as well as the ratio of the average flow velocity to circulation speed in the collector, which affects wall friction, are key factors in flow loss generation.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"157 ","pages":"Article 109803"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Power consumption model for Unmanned Aerial Vehicles using Recurrent Neural Network techniques

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109819

Amylia Ait Saadi , Bikram Pratim Bhuyan , Amar Ramdane-Cherif

Unmanned Aerial Vehicles (UAVs) have become increasingly integral across diverse sectors, necessitating accurate power consumption modeling to optimize flight operations and ensure reliability. Traditional approaches often fail to capture the intricate, non-linear dynamics between operational parameters and power usage. This study introduces deep learning techniques, including RNN, GRU, LSTM, Bi-LSTM, and SA-Bi-LSTM, with various activation functions and optimizers for predicting UAV power consumption using an extensive dataset. Additionally, the influence of activation functions and optimization algorithms on model performance is assessed. Bi-LSTM demonstrates superior predictive accuracy, as evidenced by RMSE and MAE metrics.

引用次数: 0

Preliminary aeroelastic optimization of electric aircraft wings including propeller whirl flutter effects

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109813

Zhijun Wang, Vanessa Q. Liu Xu, Roeland De Breuker

In the development of electric aircraft, due to the use of Distributed Electric Propulsion (DEP), not only the classic wing flutter but also the propeller whirl flutter needs to be considered for wing structural design. To this end, this paper proposes an aeroelastic optimization method within the framework of an in-house tool named PROTEUS, which enables the preliminary design of DEP wing laminates including propeller whirl flutter effect. In this method, a new aeroelastic model is developed for the coupled propeller-wing system, based on a classic whirl flutter analysis model and the wing aeroelastic model implemented in PROTEUS. Further, the required sensitivities of aeroelastic stability constraints are derived and implemented by making use of these implemented in PROTEUS for conventional wing design. The objective of the optimization is to minimize wing mass by aeroelastically tailoring the lamination parameters and thickness of wing laminates, subject to given aerostructural design constraints. The features and usefulness of the proposed optimization approach are demonstrated through two numerical case studies (with and without whirl flutter constraints) focused on sizing the wing structure of a reference DEP aircraft. The necessary inputs regarding propeller mounting stiffness and damping for the case studies are determined through parametric studies of isolated propellers. The results indicate that including whirl flutter effect in wing sizing slightly increases wing mass, and introducing a flexible-mount-propeller leads to the decrease in wing flutter speed. Additionally, a parametric study of investigating propeller mounting stiffness is conducted, which confirms that the propeller mounting properties have a large influence on aeroelastic instability of the coupled propeller-wing system.

{"title":"Preliminary aeroelastic optimization of electric aircraft wings including propeller whirl flutter effects","authors":"Zhijun Wang, Vanessa Q. Liu Xu, Roeland De Breuker","doi":"10.1016/j.ast.2024.109813","DOIUrl":"10.1016/j.ast.2024.109813","url":null,"abstract":"<div><div>In the development of electric aircraft, due to the use of Distributed Electric Propulsion (DEP), not only the classic wing flutter but also the propeller whirl flutter needs to be considered for wing structural design. To this end, this paper proposes an aeroelastic optimization method within the framework of an in-house tool named PROTEUS, which enables the preliminary design of DEP wing laminates including propeller whirl flutter effect. In this method, a new aeroelastic model is developed for the coupled propeller-wing system, based on a classic whirl flutter analysis model and the wing aeroelastic model implemented in PROTEUS. Further, the required sensitivities of aeroelastic stability constraints are derived and implemented by making use of these implemented in PROTEUS for conventional wing design. The objective of the optimization is to minimize wing mass by aeroelastically tailoring the lamination parameters and thickness of wing laminates, subject to given aerostructural design constraints. The features and usefulness of the proposed optimization approach are demonstrated through two numerical case studies (with and without whirl flutter constraints) focused on sizing the wing structure of a reference DEP aircraft. The necessary inputs regarding propeller mounting stiffness and damping for the case studies are determined through parametric studies of isolated propellers. The results indicate that including whirl flutter effect in wing sizing slightly increases wing mass, and introducing a flexible-mount-propeller leads to the decrease in wing flutter speed. Additionally, a parametric study of investigating propeller mounting stiffness is conducted, which confirms that the propeller mounting properties have a large influence on aeroelastic instability of the coupled propeller-wing system.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"157 ","pages":"Article 109813"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

State predictor-based deep model reference adaptive control for quadrotor trajectory tracking

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109868

Zhekun Cheng , Jueying Yang , Yi Sun , Liangyu Zhao , Lin Zhao

The application of quadrotor unmanned aerial vehicle (UAV) swarms has attracted considerable attention in recent years, but the dense formations also pose new challenges to controlling quadrotors. In these cases, quadrotors frequently encounter matched and unmatched disturbances from fellow swarm members. To achieve precise tracking of the desired trajectory with optimal accuracy, a state predictor-based deep model reference adaptive control (PDMRAC) framework is proposed. Owing to the powerful feature extraction capability of deep neural networks (DNN) and the enhancement of transient characteristics of the system by the state predictor, the control framework's performance in approximating unstructured uncertainty is improved. The controller designed based on the nonlinear model compensates for the matched uncertainty and reacts to the unmatched uncertainty to reduce the tracking error. Moreover, the controller maintains accurate tracking performance for unseen trajectories and uncertainties when well-trained DNNs are employed as frozen weight networks. Numerical simulations are conducted to evaluate trajectory tracking performance in an environment featuring time-varying disturbances, and the results demonstrate the effectiveness of the proposed method.

{"title":"State predictor-based deep model reference adaptive control for quadrotor trajectory tracking","authors":"Zhekun Cheng , Jueying Yang , Yi Sun , Liangyu Zhao , Lin Zhao","doi":"10.1016/j.ast.2024.109868","DOIUrl":"10.1016/j.ast.2024.109868","url":null,"abstract":"<div><div>The application of quadrotor unmanned aerial vehicle (UAV) swarms has attracted considerable attention in recent years, but the dense formations also pose new challenges to controlling quadrotors. In these cases, quadrotors frequently encounter matched and unmatched disturbances from fellow swarm members. To achieve precise tracking of the desired trajectory with optimal accuracy, a state predictor-based deep model reference adaptive control (PDMRAC) framework is proposed. Owing to the powerful feature extraction capability of deep neural networks (DNN) and the enhancement of transient characteristics of the system by the state predictor, the control framework's performance in approximating unstructured uncertainty is improved. The controller designed based on the nonlinear model compensates for the matched uncertainty and reacts to the unmatched uncertainty to reduce the tracking error. Moreover, the controller maintains accurate tracking performance for unseen trajectories and uncertainties when well-trained DNNs are employed as frozen weight networks. Numerical simulations are conducted to evaluate trajectory tracking performance in an environment featuring time-varying disturbances, and the results demonstrate the effectiveness of the proposed method.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"157 ","pages":"Article 109868"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Spectral proper orthogonal decomposition of turbine tip clearance flow under low-Reynolds number conditions

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109809

Ziyi Shao , Haiyan Zhang , Bo Pan

Spectral proper orthogonal decomposition, a data-based decomposition technique, was performed to extract key spatiotemporal coherent structures from large-eddy simulation data. Both velocity and vorticity were decomposed to identify the dominant unsteady features around the near-tip region. Four operating conditions for two different Reynolds numbers, with and without tip clearance were investigated, i.e., low_Re TC, low_Re, high_Re TC and high_Re. The energy spectra (eigenvalues) and their accumulation at each frequency exhibited the low-rank behavior, indicating the presence of a physically dominating mechanism. The velocity mode shapes (eigenvectors) revealed three typical coherent structures for the low_Re TC condition: vortex shedding from the blade wake and the tip leakage vortex, Kelvin-Helmholtz instability induced by the leakage jet, and complex interactions among the boundary layer separation, the tip leakage vortex and the horseshoe vortex. For the condition without tip clearance, the dominant structure was the vortex shedding from the wake only. The vorticity mode shapes indicated that high dissipation of the vorticity field occurred close to the suction side, where strong secondary vortices existed. The present research could develop a better understanding of turbine tip clearance flow and loss mechanisms at low Reynolds numbers.

{"title":"Spectral proper orthogonal decomposition of turbine tip clearance flow under low-Reynolds number conditions","authors":"Ziyi Shao , Haiyan Zhang , Bo Pan","doi":"10.1016/j.ast.2024.109809","DOIUrl":"10.1016/j.ast.2024.109809","url":null,"abstract":"<div><div>Spectral proper orthogonal decomposition, a data-based decomposition technique, was performed to extract key spatiotemporal coherent structures from large-eddy simulation data. Both velocity and vorticity were decomposed to identify the dominant unsteady features around the near-tip region. Four operating conditions for two different Reynolds numbers, with and without tip clearance were investigated, i.e., low_<em>Re</em> TC, low_<em>Re</em>, high_<em>Re</em> TC and high_<em>Re</em>. The energy spectra (eigenvalues) and their accumulation at each frequency exhibited the low-rank behavior, indicating the presence of a physically dominating mechanism. The velocity mode shapes (eigenvectors) revealed three typical coherent structures for the low_<em>Re</em> TC condition: vortex shedding from the blade wake and the tip leakage vortex, Kelvin-Helmholtz instability induced by the leakage jet, and complex interactions among the boundary layer separation, the tip leakage vortex and the horseshoe vortex. For the condition without tip clearance, the dominant structure was the vortex shedding from the wake only. The vorticity mode shapes indicated that high dissipation of the vorticity field occurred close to the suction side, where strong secondary vortices existed. The present research could develop a better understanding of turbine tip clearance flow and loss mechanisms at low Reynolds numbers.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"157 ","pages":"Article 109809"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

GD-DORGP: A data-driven framework for free geometry design and accurate real-time multi-physics evaluation of unseen hypersonic aircraft structures using limited data

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109774

Lifu Wei , Yunguo Cheng , Chensen Ding

Quickly redesigning hypersonic aircraft structures and accurately evaluating the full-field response is crucial and significantly challenging. Therefore, this paper proposes a novel data-driven scheme, GD-DORGP, which encompasses a non-parametric adaptive characterization method for freely designing complex geometric deformations (GD) and dual order-reduced Gaussian Process (DORGP) emulators to predict full-field multi-physics responses in real time. First, we propose a unified feature characterization for aircraft structures, employing adaptive virtual sensor arrays to encode complex geometry information. This non-parametric approach comprehensively extracts base model and deformation information, making it capable of aircraft with complex geometric deformations. Secondly, we advance the dual order-reduced Gaussian Process (DORGP) regression, which builds a probabilistic map between the virtual sensor array characterizations of structures with global complex and local detailed deformations, and the full-field multi-physical information. Thirdly, we freely design aircraft with significant geometric deformations, and accurately predict the large-scale pressure and temperature distributions, addressing the formidable computational challenges inherent in hypersonic problems. Several examples, including real-life aircraft with hypersonic boundary conditions, verify the proposed GD-DORGP can freely design the hypersonic aircraft and accurately predict the full-field pressure and temperature in real time with limited data.

{"title":"GD-DORGP: A data-driven framework for free geometry design and accurate real-time multi-physics evaluation of unseen hypersonic aircraft structures using limited data","authors":"Lifu Wei , Yunguo Cheng , Chensen Ding","doi":"10.1016/j.ast.2024.109774","DOIUrl":"10.1016/j.ast.2024.109774","url":null,"abstract":"<div><div>Quickly redesigning hypersonic aircraft structures and accurately evaluating the full-field response is crucial and significantly challenging. Therefore, this paper proposes a novel data-driven scheme, GD-DORGP, which encompasses a non-parametric adaptive characterization method for freely designing complex geometric deformations (GD) and dual order-reduced Gaussian Process (DORGP) emulators to predict full-field multi-physics responses in real time. <strong>First,</strong> we propose a unified feature characterization for aircraft structures, employing adaptive virtual sensor arrays to encode complex geometry information. This non-parametric approach comprehensively extracts base model and deformation information, making it capable of aircraft with complex geometric deformations. <strong>Secondly,</strong> we advance the dual order-reduced Gaussian Process (DORGP) regression, which builds a probabilistic map between the virtual sensor array characterizations of structures with global complex and local detailed deformations, and the full-field multi-physical information. <strong>Thirdly,</strong> we freely design aircraft with significant geometric deformations, and accurately predict the large-scale pressure and temperature distributions, addressing the formidable computational challenges inherent in hypersonic problems. <strong>Several examples</strong>, including real-life aircraft with hypersonic boundary conditions, verify the proposed GD-DORGP can freely design the hypersonic aircraft and accurately predict the full-field pressure and temperature in real time with limited data.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"157 ","pages":"Article 109774"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Effects of the cooling jets on the flame characteristics and wall temperature of air-cooled wall-strut flameholders

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109781

Hedong Liu , Yuqian Chen , Xu Shan , Junyan Zhu , Yuxin Fan , Yue Huang , Yancheng You

Air-cooled flameholder is a credible solution for restraining the increasingly raised inlet temperature and operation cycle of advanced afterburner/ramjet combustors. In previous study, the effects of cooling jets on the flow and cooling film characteristics of an air-cooled integrated flameholder (coupled with wall and strut parts) have been revealed by numerical analysis. Furthermore, this work aims to reveal the influence of jet cooling schemes and cooling jet conditions on the fuel spray, flame structure, and wall temperature of air-cooled wall-strut flameholder. Experiments were performed to obtain the flame structures and wall temperature distributions. Numerical simulation with a Discrete Phase Model was employed to analyze the distribution characteristics of vapor-phase fuel. The results suggest that the changes of cooling jet angle significantly affect both the vapor-phase fuel distribution in the backward-facing step region and the radial wake region. Moreover, as the mainstream velocity increases, the pilot flame temperature and area decrease, and its radial propagation capability worsens. An increase in the flow rate of radial cooling jet would lead to local extinction and deteriorate flame uniformity. Therefore, the cooling effectiveness of the air-cooled wall-strut flameholder is significantly influenced by the wall and radial cooling jet angles, as well as the aerodynamic conditions. Overall, when cooling hole angles on the wall-type step of α = 30°, β = 30°, and that on the radial strut of θ = 90°, the air-cooled wall-strut flameholder exhibits the best comprehensive performance.

{"title":"Effects of the cooling jets on the flame characteristics and wall temperature of air-cooled wall-strut flameholders","authors":"Hedong Liu , Yuqian Chen , Xu Shan , Junyan Zhu , Yuxin Fan , Yue Huang , Yancheng You","doi":"10.1016/j.ast.2024.109781","DOIUrl":"10.1016/j.ast.2024.109781","url":null,"abstract":"<div><div>Air-cooled flameholder is a credible solution for restraining the increasingly raised inlet temperature and operation cycle of advanced afterburner/ramjet combustors. In previous study, the effects of cooling jets on the flow and cooling film characteristics of an air-cooled integrated flameholder (coupled with wall and strut parts) have been revealed by numerical analysis. Furthermore, this work aims to reveal the influence of jet cooling schemes and cooling jet conditions on the fuel spray, flame structure, and wall temperature of air-cooled wall-strut flameholder. Experiments were performed to obtain the flame structures and wall temperature distributions. Numerical simulation with a Discrete Phase Model was employed to analyze the distribution characteristics of vapor-phase fuel. The results suggest that the changes of cooling jet angle significantly affect both the vapor-phase fuel distribution in the backward-facing step region and the radial wake region. Moreover, as the mainstream velocity increases, the pilot flame temperature and area decrease, and its radial propagation capability worsens. An increase in the flow rate of radial cooling jet would lead to local extinction and deteriorate flame uniformity. Therefore, the cooling effectiveness of the air-cooled wall-strut flameholder is significantly influenced by the wall and radial cooling jet angles, as well as the aerodynamic conditions. Overall, when cooling hole angles on the wall-type step of <em>α</em> = 30°, <em>β</em> = 30°, and that on the radial strut of <em>θ</em> = 90°, the air-cooled wall-strut flameholder exhibits the best comprehensive performance.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"157 ","pages":"Article 109781"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Analytical and experimental study on a versatile landing system with shock response mechanism

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109807

Pengcheng Li , Ryuki Sato , Susumu Hara

This paper introduces a versatile, passive-landing system designed for various landing operations such as planetary exploration missions, emergency landings of unmanned aerial vehicles (UAVs), and so on. The system leverages energy and momentum exchange mechanisms, incorporating two spring units and a detachable flyaway component to ensure smooth and safe landings. Initially, the kinetic energy of the lander is converted into potential energy stored in the spring units. A switch mechanism then releases this stored energy, converting it back into kinetic energy and transferring momentum to the flyaway part. This process effectively suppresses rebound and reduces acceleration, ensuring a soft landing. A key advantage of this mechanism is its high robustness against variations in initial-fall height. The energy stored in the spring units adjusts according to the falling height, enhancing the system adaptability. The system performance is evaluated through one-dimensional simulations to assess rebound height and acceleration, and two-dimensional simulations to evaluate its ability to prevent tip-over. An experimental setup further validates the system-rebound suppression capability. Results from both simulations and experiments confirm the superior system performance in minimizing rebound, reducing acceleration, and preventing rotational motion during landing.

{"title":"Analytical and experimental study on a versatile landing system with shock response mechanism","authors":"Pengcheng Li , Ryuki Sato , Susumu Hara","doi":"10.1016/j.ast.2024.109807","DOIUrl":"10.1016/j.ast.2024.109807","url":null,"abstract":"<div><div>This paper introduces a versatile, passive-landing system designed for various landing operations such as planetary exploration missions, emergency landings of unmanned aerial vehicles (UAVs), and so on. The system leverages energy and momentum exchange mechanisms, incorporating two spring units and a detachable flyaway component to ensure smooth and safe landings. Initially, the kinetic energy of the lander is converted into potential energy stored in the spring units. A switch mechanism then releases this stored energy, converting it back into kinetic energy and transferring momentum to the flyaway part. This process effectively suppresses rebound and reduces acceleration, ensuring a soft landing. A key advantage of this mechanism is its high robustness against variations in initial-fall height. The energy stored in the spring units adjusts according to the falling height, enhancing the system adaptability. The system performance is evaluated through one-dimensional simulations to assess rebound height and acceleration, and two-dimensional simulations to evaluate its ability to prevent tip-over. An experimental setup further validates the system-rebound suppression capability. Results from both simulations and experiments confirm the superior system performance in minimizing rebound, reducing acceleration, and preventing rotational motion during landing.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"157 ","pages":"Article 109807"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 using micro-second pulsed plasma discharge to mitigate thermoacoustic instability in Rijke tube

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109843

Jiangge Deng , Ting Li , Chicheng Gao

Thermoacoustic instability is a common problem in many kinds of combustors, especially for lean burn combustor. As a classic device for studying the mechanism thermoacoustic oscillations, a Rijke tube was studied numerically and experimentally, and it was demonstrated that the thermoacoustic oscillations can be mitigated by the Micro-second Pulsed plasma discharge. A SIMULINK code was built based on the acoustic network model to investigate the influence of the pulsed violent thermal and acoustic shocks of plasma discharge on the thermoacoustic system. This simulation results show the key parameters in a thermoacoustic system which helped to determine the effect of plasma discharge on the thermoacoustic system. First, the pulsed thermal and acoustic shocks of the pulsed plasma discharge were simulated and verified based on the experimental results. It was demonstrated that the average power of plasma discharge was the key factor in suppression of the thermoacoustic oscillation, as well as the energy of the single pulse. When the total energy of the plasma discharge burst was fixed, mechanisms of two different control schemes were illustrated, and increasing the single-pulse energy was more effective than increasing the repetition rate of the plasma discharge. Finally, strategies for plasma discharge parameters used to effectively mitigate the combustion instabilities were discussed.

{"title":"Investigation of using micro-second pulsed plasma discharge to mitigate thermoacoustic instability in Rijke tube","authors":"Jiangge Deng , Ting Li , Chicheng Gao","doi":"10.1016/j.ast.2024.109843","DOIUrl":"10.1016/j.ast.2024.109843","url":null,"abstract":"<div><div>Thermoacoustic instability is a common problem in many kinds of combustors, especially for lean burn combustor. As a classic device for studying the mechanism thermoacoustic oscillations, a Rijke tube was studied numerically and experimentally, and it was demonstrated that the thermoacoustic oscillations can be mitigated by the Micro-second Pulsed plasma discharge. A SIMULINK code was built based on the acoustic network model to investigate the influence of the pulsed violent thermal and acoustic shocks of plasma discharge on the thermoacoustic system. This simulation results show the key parameters in a thermoacoustic system which helped to determine the effect of plasma discharge on the thermoacoustic system. First, the pulsed thermal and acoustic shocks of the pulsed plasma discharge were simulated and verified based on the experimental results. It was demonstrated that the average power of plasma discharge was the key factor in suppression of the thermoacoustic oscillation, as well as the energy of the single pulse. When the total energy of the plasma discharge burst was fixed, mechanisms of two different control schemes were illustrated, and increasing the single-pulse energy was more effective than increasing the repetition rate of the plasma discharge. Finally, strategies for plasma discharge parameters used to effectively mitigate the combustion instabilities were discussed.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"157 ","pages":"Article 109843"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Study on heat release characteristics of the dual composite flame stabilizers for the dual-mode scramjet

IF 5 1区工程技术 Q1 ENGINEERING, AEROSPACE

Aerospace Science and Technology

Pub Date : 2025-02-01 DOI: 10.1016/j.ast.2024.109703

Xingliang Chen, Shaohua Zhu, Bing Liu, Huamin Zhang, Zongyuan Guo, Fei Qin

The paper studies the heat release (HR) characteristics of a dual-mode scramjet equipped with the dual composite flame stabilizers under simulated free-stream conditions of Mach 6 and dynamic pressure of 30 kPa, through ground direct-connected tests and OpenFOAM numerical simulation. This study focuses on the three-dimensional distribution of subsonic/supersonic HR, local combustion modes, and the variations in HR during the ram-scram mode transition. The results indicate that the high-enthalpy jet transports the high-temperature and fuel-rich gas in the cavity to the mainstream through the ejection effect of the supersonic flow, causing the heat release zone to move to the mainstream. So that the mainstream subsonic-diffusion combustion zone is expanded and is evenly distributed, and then the HR trailing zone downstream of the thermal throat is shortened. The study highlights the different matching characteristics between subsonic flow and HR formed by the dual composite flame stabilizers under high and low equivalence ratio (ER). Optimized injection schemes need to be selected to obtain higher combustion efficiency at different equivalence ratios. In the region of the first-stage composite flame stabilizer, a distinct phenomenon of subsonic/supersonic mixed HR is observed. Subsonic HR predominates under the ramjet mode, while the subsonic HR tends to equal supersonic HR under the scramjet mode. Upstream of the thermal throat, subsonic HR exceeds 80 %, and supersonic heat release has a tendency to gradually decrease. Furthermore, when the ER of two-stage dispersed injection is <0.5, the heating amount per kilogram of air is <1.06 MJ, and the thermal throat cannot be formed, causing the ram-scram mode transition to occur. Conversely, for single-stage concentrated injection, the boundary of ER and heating amount decreases. The study provides support for the design of injection schemes and the regulation of mode transition for dual-mode scramjet based on the HR performance.

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