Shicai Huang , Ye Tian , Xue Deng , Maotao Yang , Erda Chen , Hua Zhang
{"title":"Supersonic combustion flow field reconstruction in a scramjet based on deep learning method","authors":"Shicai Huang , Ye Tian , Xue Deng , Maotao Yang , Erda Chen , Hua Zhang","doi":"10.1016/j.ast.2025.110169","DOIUrl":"10.1016/j.ast.2025.110169","url":null,"abstract":"<div><div>Efficiently predicting combustion flow in scramjet engines enhances early state awareness, which is crucial for facilitating active flow control and ensuring reliable and stable engine operation. Aiming at the problem that the traditional optical test method of ground wind tunnel test is limited by complex and narrow space and difficult to obtain data, the study introduces a supersonic flow field reconstruction model that utilizes local-global feature grouping and fusion to realize fast reconstruction of flow field schlieren image based on sparse pressure data obtained by tiny wall pressure sensor. To prevent the loss of many shallow gradients in the transmission process, a two-layer gradient calculation strategy is designed to preserve the shallow gradient features to the maximum extent. To reduce the number of model parameters and enhance the information crafty interaction between different flow fields, a binary segmentation mask strategy is designed to transform the image dimensionality and block. To assess the effectiveness of the proposed model, experiments were conducted using hydrogen fuel combustion test data obtained from a pulse combustion wind tunnel with an inflow Mach number of 2.5. When compared to other models, our model demonstrated a significant 14.37 % improvement in structural similarity and an 8.35 % improvement in peak signal-to-noise ratio indicators. Most notably, these improvements were achieved while maintaining the lowest computational complexity.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110169"},"PeriodicalIF":5.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725414","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}
Miaomiao Tian , Nan Wang , Zhikai Wang , Zhumu Fu , Fazhan Tao
{"title":"Prescribed-time fault-tolerant tracking control for quadrotor UAV with guaranteed performance","authors":"Miaomiao Tian , Nan Wang , Zhikai Wang , Zhumu Fu , Fazhan Tao","doi":"10.1016/j.ast.2025.110162","DOIUrl":"10.1016/j.ast.2025.110162","url":null,"abstract":"<div><div>During the actual flight of unmanned aerial vehicle (UAV), there are widespread actuator faults, system uncertainties and external disturbances, which bring significant threats to its steady flight. This paper studies the problem of prescribed-time fault-tolerant tracking control for quadrotor UAV with guaranteed performance. By integrating error reconstruction and dynamic adjustment strategies, this paper ensures that the position and attitude tracking errors converge to the preset performance range within the prescribed time. Furthermore, this paper utilizes the disturbance observer failure compensation method to simultaneously handle the multiplicative and additive failures of the actuator simultaneously, and presents a nonlinear observer-based adaptive strategy to estimate additive faults and unknown external disturbances acting on the UAV. Simulation results show that the position and attitude tracking errors converge to the preset accuracy within the prescribed time without actuator failures. When actuator failures occur, the attitude tracking error still converges on time, and the convergence rate of position error is minimally affected. Thus, the proposed control algorithm for quadrotor UAV is validated.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110162"},"PeriodicalIF":5.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704200","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}
Ziyu Qin , Heng Song , Xiao Han , Lei Li , Yuzhen Lin , Liangliang Xu
{"title":"Fuel stratification effects on thermoacoustic instability for swirl spray flame in an aero-engine centrally-staged combustor","authors":"Ziyu Qin , Heng Song , Xiao Han , Lei Li , Yuzhen Lin , Liangliang Xu","doi":"10.1016/j.ast.2025.110163","DOIUrl":"10.1016/j.ast.2025.110163","url":null,"abstract":"<div><div>The centrally-staged combustor features a flexible radial fuel stratification to achieve well-organized energy utilization but still faces serious thermoacoustic instability. In this study, we conducted experiments with four stratification ratios (SRs) under the realistic stratified swirl spray flame configuration. The stratification effect on thermoacoustic instability is investigated using the 20 kHz simultaneous PIV and CH<sub>2</sub>O-PLIF optical diagnostic. The combustor is prone to severe thermoacoustic oscillation at lower SR, in which the pressure fluctuation substantially follows the heat release dynamic with a short time delay. At higher SR, the relative phase between them becomes irregular accompanied by intermittent oscillations. Two types of flame dynamics are found. The heat release region features an axial mode for lower SR, while it presents the transverse oscillation which destroys the thermoacoustic coupling for higher SR. Further, a coupling metric quantifying the similarity between the vortex probability distribution and flame surface density is proposed to measure the vortex-flame coupling. The highest value for the lowest SR is attributed to the strong flame-flow interaction downstream of the primary recirculation zone, which contributes to the unsteady heat release. Finally, it is found that the local flame stabilization is similar to the counterflow flame.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110163"},"PeriodicalIF":5.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746874","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}
Haibin Sun , Yi Xu , Linlin Hou , Dong Yang , Ticao Jiao
{"title":"Composite anti-unwinding sliding mode attitude tracking control for rigid spacecraft: A prescribed-time method","authors":"Haibin Sun , Yi Xu , Linlin Hou , Dong Yang , Ticao Jiao","doi":"10.1016/j.ast.2025.110158","DOIUrl":"10.1016/j.ast.2025.110158","url":null,"abstract":"<div><div>This study addresses the prescribed-time anti-unwinding attitude tracking control problem for a rigid spacecraft. First, a prescribed-time sliding mode disturbance observer is designed to estimate the disturbances. To ensure prescribed-time convergence and avoid the unwinding phenomenon, a new prescribed-time sliding mode surface is established by introducing a hyperbolic sine function such that the designed sliding surface includes two equilibrium points. Subsequently, an attitude tracking control law with a disturbance compensation term is designed to guarantee that the system states converge to the sliding surface in a prescribed-time. The simulation results reveal that anti-unwinding prescribed-time attitude tracking of a rigid spacecraft can be achieved by using the developed attitude control law.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110158"},"PeriodicalIF":5.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687627","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}
Siyi Zhang , Xiaokang Liu , Yu Tian , Dongbin Wang , Jingxuan Li , Lijun Yang
{"title":"Investigations on the competition between acoustic and intrinsic thermoacoustic modes due to multi-flame interaction","authors":"Siyi Zhang , Xiaokang Liu , Yu Tian , Dongbin Wang , Jingxuan Li , Lijun Yang","doi":"10.1016/j.ast.2025.110159","DOIUrl":"10.1016/j.ast.2025.110159","url":null,"abstract":"<div><div>Thermoacoustic instabilities typically consist of two modes: the acoustic instability mode and the intrinsic thermoacoustic (ITA) mode. These modes can coexist and compete under certain conditions within a combustor. This paper investigates the impact of multi-flame interaction on mode competition within a model combustor – a length-adjustable Rijke tube. Mode competition was explored by independently varying the chamber's acoustic characteristics (via Rijke tube length) and the multi-flame response characteristics (through injector hole distribution). The thermoacoustic response of the multi-flame system was examined using an acoustic pressure sensor and CH* chemiluminescence technique. The dynamic properties of the multi-flame flow field were captured with a high-speed camera and particle image velocimetry (PIV). Results showed that different multi-flame interactions can alter the flame transfer function (FTF), leading to combustion instability dominated by either the acoustic mode or the ITA mode. The experimental results were combined with a low-order acoustic network model (LOM) to study the transition and competition between acoustic and ITA instability under multi-flame interactions. The predictions of the LOM for the eigenfrequencies and growth rates of the combustion system can accurately describe the occurrence trend of the acoustic and ITA modes.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110159"},"PeriodicalIF":5.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746873","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}
{"title":"Study on the interaction mechanism between incident oblique shock wave and transpiration cooling and optimization of porosity","authors":"Xiaojuan Wang, Xiaoqiang Fan, Bing Xiong","doi":"10.1016/j.ast.2025.110154","DOIUrl":"10.1016/j.ast.2025.110154","url":null,"abstract":"<div><div>Transpiration cooling, due to its high cooling efficiency, is used for thermal protection in hypersonic aircraft. However, oblique shock waves incident on a structural surface can reduce cooling effectiveness, risking thermal protection failure. Additionally, the cooling film changes the wave structure in the main flow, reducing the aerodynamic performance. This study employs numerical methods to analyze the effects of oblique shock waves on transpiration cooling at various shock incidence angles and coolant blowing ratios, as well as the influence of transpiration cooling on the main flow field. The cooling efficiency curve is segmented into four intervals based on the flow mechanisms, with the corresponding optimization objectives proposed. A segmented porosity design method driven by pressure difference is adopted, improving the surface temperature uniformity at the hot end of the transpiration zone by 82.7%.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110154"},"PeriodicalIF":5.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685461","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}
{"title":"Reinforcement learning of composite disturbance observer based tracking control for unmanned aerial helicopter under outside disturbances","authors":"Chunyu Zhang, Changyu Lu, Tao Li, Zehui Mao","doi":"10.1016/j.ast.2025.110156","DOIUrl":"10.1016/j.ast.2025.110156","url":null,"abstract":"<div><div>This paper proposes a reinforcement learning (RL) approach with composite disturbance observer to investigate the tracking control for medium-scale unmanned aerial helicopter (UAH) under outside disturbances and model uncertainties. Each disturbance consists of a modelable component and a bounded time-varying one, which better reflects real-world scenarios. Firstly, to facilitate controller design, the nonlinear UAH model is decomposed into position and attitude loops. Secondly, for the position loop, an actor-critic network structure is utilized to approximate model uncertainties while a design of composite disturbance observer including a coordinated disturbance observer (CDO) and a nonlinear disturbance observer (NDO) is presented to estimate outside disturbance and approximation error. The CDO employs a master DO and multiple slave DOs working in coordination to ensure rapid convergence of modelable disturbances under small gain conditions. Additionally, adaptive laws are developed for the weights of the actor and critic networks. Notably, system modeling error is incorporated into the weight update of the actor network to promote the rapid convergence of the weights. Thirdly, by combining tracking errors with the aforementioned estimations and approximations, a position tracking controller is developed to derive the corresponding closed-loop system. On the other hand, the attitude tracking controller is implemented similarly to the position loop, except for that the dynamic surface technique is employed to simplify analytical calculations. Fourthly, the Lyapunov stability theory is applied to prove that all error signals of the overall closed-loop system are uniformly ultimately bounded, and a co-design method for the CDOs, network weights, and controllers is developed based on a set of inequalities, demonstrating that its capability can not only effectively address the disturbances and uncertainties, but also significantly improve the tracking accuracy and UAH system stability.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110156"},"PeriodicalIF":5.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678387","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}
Fanggang Zhang , Lei Luo , Jiahui Zhang , Weiguang Cai , Shu Zheng , Xingyan Tang , Wenzhe Cai , Ran Sui
{"title":"A strategy for enhancing ignition of aviation fuels at high altitudes using nanoparticle and fuel-soluble catalysts","authors":"Fanggang Zhang , Lei Luo , Jiahui Zhang , Weiguang Cai , Shu Zheng , Xingyan Tang , Wenzhe Cai , Ran Sui","doi":"10.1016/j.ast.2025.110160","DOIUrl":"10.1016/j.ast.2025.110160","url":null,"abstract":"<div><div>Improving the ignition performance of aviation fuels in high-altitude environments is essential for the reliable operation of aero-engines. This study investigated the catalytic ignition of RP-3 aviation fuel at high-altitudes using Co<sub>3</sub>O<sub>4</sub> nanoparticles and fuel-soluble catalysts (platinum and palladium acetylacetonates). Ignition delay times (IDT) and ignition probabilities (IP) were measured <em>in situ</em> using thermocouples and a spectrometer. The results demonstrated that the addition of 150 ppm Co<sub>3</sub>O<sub>4</sub> nanoparticles exhibited the best catalytic performance, achieving 100% IP with the shortest average IDT of 1.41 s. In contrast, the IP of RP-3 without catalysts was only 25%, with an average IDT above 15.92 s. The fuel-soluble catalysts also significantly improved the ignition performance. With 150 ppm addition, both cases reached 100% IP but longer IDTs than that of Co<sub>3</sub>O<sub>4</sub>. Thermogravimetric analysis indicated that Co<sub>3</sub>O<sub>4</sub> nanoparticles catalyzed ignition through the Mars-van Krevelen mechanism at lower temperatures, while at higher temperatures they decomposed into CoO and O<sub>2</sub>, further facilitating ignition through both catalytic effect and the increased amount of oxidant. On the other hand, the fuel-soluble catalysts decomposed into noble metals or their oxidants that provided active sites for the surface oxidation of the fuel, with the heat release from this process initiating gas-phase ignition. These results provide a new strategy for ignition enhancement of aviation fuels in extreme environments via catalytic combustion.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110160"},"PeriodicalIF":5.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703954","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}
Daniel Carroll , Michael Pott-Polenske , Gareth J. Bennett
{"title":"Air curtains for landing gear noise reduction","authors":"Daniel Carroll , Michael Pott-Polenske , Gareth J. Bennett","doi":"10.1016/j.ast.2025.110139","DOIUrl":"10.1016/j.ast.2025.110139","url":null,"abstract":"<div><div>This paper examines the implementation of air curtain nozzles to reduce the aerodynamic noise radiated from a modified scaled LAGOON landing gear and a detailed trailing-arm Main Landing Gear representing a generic Bizjet wing mounted gear provided by Dassault Aviation and Safran Landing Systems. At approach to landing, landing gear noise is still a significant contributor to environmental noise in the vicinity of airports. Progress is being made with ambitious projects which aim to develop significantly reconfigured aircraft architectures to reduce airframe noise. The current project examines a noise abatement concept which could be retrofitted to existing landing gear configurations as an interim measure or as part of a longer term solution. Flow control in the form of “air curtain” nozzles which create a fluidic shield or virtual fairing are examined. The air curtain concept was examined as a low test-readiness-level (TRL), high-risk, high-gain technology tested in the EU funded H2020 collaborative research project: INVENTOR, InnoVative dEsign of iNstalled airframe componenTs for aircraft nOise Reduction. The nozzles operate at high pressure with rows of choked-flow sub-millimeter holes. Narrow and broadband noise attenuation was achieved, with reductions of over 7 dB measured. The air curtains were examined in DLR's AWB aeroacoustic facility in Braunschweig, Germany.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110139"},"PeriodicalIF":5.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687598","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}
Antariksh Dicholkar , Kenneth Lønbæk , Mads H.Aa. Madsen , Frederik Zahle , Niels N. Sørensen
{"title":"From bluff bodies to optimal airfoils: Numerically stabilized RANS solvers for reliable shape optimization","authors":"Antariksh Dicholkar , Kenneth Lønbæk , Mads H.Aa. Madsen , Frederik Zahle , Niels N. Sørensen","doi":"10.1016/j.ast.2025.110153","DOIUrl":"10.1016/j.ast.2025.110153","url":null,"abstract":"<div><div>The robustness of Reynolds-Averaged Navier-Stokes (RANS) solvers is a significant challenge in gradient-based aerodynamic shape optimization, especially when encountering shapes that produce highly separated flows. These cases often cause solvers to diverge or exhibit limit-cycle oscillations. Common practices rely on averaging non-converged solutions and often yield gradients that mislead optimizers, resulting in poor designs or failure. To address this, we extend the modified-BoostConv method to ensure full convergence of SIMPLE-based RANS solvers in such conditions, providing model-accurate gradients using the complex-step derivative technique.</div><div>Building on previous work, we introduce a novel coupling approach that resolves stability issues in earlier implementations of the modified-Boostconv method by splitting the basis construction for complex residuals into its solution (real) and gradient (imaginary) components. The gradient accuracy of averaged solutions from non-converging solvers is compared to fully converged gradients using the chaotic logistic map equation and a RANS simulation of a bluff body undergoing massive flow separation.</div><div>We then optimize a shape starting from a 80% thick bluff body, demonstrating the importance of accurate gradients. Using model-accurate gradients, we obtain an optimized 18% thick airfoil with a high lift-to-drag ratio, matching the results of optimizing a NACA 0018 airfoil and indicating the presence of a global optimum. Conversely, optimization with averaged gradients failed to improve the initial shape.</div><div>This study highlights the limitations of gradient averaging for non-converging solvers. It demonstrates that fully converged gradients reliably guide the optimizer toward attached flow regions, where RANS models are more accurate and reliable.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110153"},"PeriodicalIF":5.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678389","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}