Aerospace Science and Technology最新文献

{"title":"Research on the cooling performance and thermal stress characteristic of turbine blade with typical array film holes","authors":"Chengliang Lv ,&nbsp;Longfei Wang ,&nbsp;Junkui Mao ,&nbsp;Yiming Liu ,&nbsp;Xinzi Liu ,&nbsp;Dewei Zhang ,&nbsp;Zhongran Chi","doi":"10.1016/j.ast.2025.111035","DOIUrl":"10.1016/j.ast.2025.111035","url":null,"abstract":"<div><div>A real turbine stator is selected as the research object, and cooling performance and thermal stress characteristic of blades with varying film cooling hole geometries-namely circular holes, shaped holes, and 7–7–7 holes-are studied through high temperature experiment and numerical simulation. Compared to circular hole blade, the cooling efficiency of shaped hole blade is improved by 12.99 %, the overall thermal stress is reduced by 17.12 %, and the thermal stress in the maximum 10 % interval is reduced by 24.34 %. It is an optimal scheme for the film holes with great cooling efficiency and low thermal stress. The ability of the shaped hole and 7–7–7 hole blades to improve blade cooling efficiency and reduce surface thermal stress is similar, but the former is slightly better at reducing thermal stress in the blade root and suction-side film hole outflow regions. The aerothermal parameters under different engine operating conditions impact the ability of the shaped hole blades to enhance the cooling efficiency and lower the surface thermal stress. Improvement of blade cooling efficiency is more significant at small temperature ratio and small blowing ratio, and the reduction of the blade surface thermal stress is more obvious at large temperature ratio or large blowing ratio. As the blowing ratio varies along with the engine operating conditions, thermal stress on blade pressure side and suction side with shaped holes are obviously reduced, and the drastic changes of thermal stress in the local area of blade leading edge are also effectively mitigated.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 111035"},"PeriodicalIF":5.8,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266474","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":"A CFD study of the aerodynamic characteristics of a DrivAer fastback model","authors":"Thanh-Long Le ,&nbsp;Thanh-Phuc Phan ,&nbsp;Duc Tran ,&nbsp;Viet-Thang Vu ,&nbsp;Le-Hung-Toan Do","doi":"10.1016/j.ast.2025.111043","DOIUrl":"10.1016/j.ast.2025.111043","url":null,"abstract":"<div><div>This study focuses on improving the aerodynamic performance of a passenger vehicle by incorporating an aerodynamic add-on device. Specifically, a cambered rear wing based on the NACA 8612 airfoil is mounted at the rear of the DrivAer fastback model to enhance its aerodynamic characteristics. Then, the computational fluid dynamics (CFD) approach is employed to investigate the fluid dynamic behavior and evaluate the aerodynamic performance improvements resulting from the rear wing installation. The analysis also examines the effects of operational conditions and wing configuration parameters, such as freestream velocities, mounting heights, and angles, on the drag and lift coefficients. Numerical simulation results reveal that applying a rear wing with a configuration of a/b = 0.8 and α = 5° at a vehicle speed of 30 m/s leads to a significant improvement in aerodynamic stability compared to the original model, as evidenced by the reduction in the lift area coefficient from 0.291 to -0.124, at the cost of a slight drag area coefficient increase from 0.503 to 0.515. Overall, the findings in this study aim to contribute to a deeper understanding of how aerodynamic add-on devices influence a vehicle’s aerodynamic performance. In particular, the analysis of various wing configuration parameters offers valuable insights for the development of active aerodynamic control systems, particularly in designing effective control strategies.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 111043"},"PeriodicalIF":5.8,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265578","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":"Composite control and error suppression for space opto-electronic tracking turntable considering friction characteristic compensation","authors":"Chaoyong Guo ,&nbsp;Ruoying Liu ,&nbsp;Lei Tong ,&nbsp;Yucong Xiong ,&nbsp;Jikui Liu ,&nbsp;Qiang Zhang","doi":"10.1016/j.ast.2025.110939","DOIUrl":"10.1016/j.ast.2025.110939","url":null,"abstract":"<div><div>Space opto-electronic turntables are increasingly utilized in space situational awareness missions and high-speed laser communication. However, during full-range maneuvers, these turntables experience significant nonlinear friction forces due to the axis system and friction generated by the conductive ring. These friction forces exhibit drastic changes when the speed exceeds zero, resulting in error spikes. Additionally, the turntable has a structural characteristic of large inertia, which contributes to lagging tracking errors. In order to suppress the tracking error and improve the dynamic performance of the space opto-electronic turntable, this paper proposes a composite control strategy that integrates friction characteristic observation and compensation with position feedforward. The model of friction load such as conductive rings is identified and observed, and the friction torque is reconstructed and compensated by the LuGre model. Furthermore, a composite feedforward control is implemented to mitigate the tracking hysteresis error. The effectiveness of the proposed method is verified through simulation and experimentation. The results demonstrate that the composite control method integrated friction characteristic observation and compensation with position feedforward significantly improves the control bandwidth and obviously reduces the tracking error of the opto-electronic turntable servo system. This innovative control strategy not only advances the performance of opto-electronic turntables but also holds significant implications for the design of other high-performance pointing and tracking servo systems in various applications.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 110939"},"PeriodicalIF":5.8,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219738","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":"Predefined-time attitude control for hypersonic morphing vehicles using morphing information-driven event","authors":"Hao Zhang,&nbsp;Wenxing Fu","doi":"10.1016/j.ast.2025.110940","DOIUrl":"10.1016/j.ast.2025.110940","url":null,"abstract":"<div><div>This research investigates the attitude control system design for hypersonic morphing vehicles (HMVs) subject to limited system resources. HMVs are always developed to perform cross-domain flights, which includes cross velocity-range and airspace segments. These conditions and complex flight environments lead to serious flight control issues: 1) fast attitude-tracking is required for HMVs; 2) HMVs are systems with limited system resources, demanding system resource preservation in the condition of high-performance tracking. Therefore, the following work is arranged to address the control issue. Firstly, a multivariable predefined-time control (PTC) system is developed for the HMV attitude system. A predefined-time command filter is constructed to avoid the “explosion of derivative” issue. With the help of the predefined-time control strategy, back-stepping control method, and the command filter, the ideal predefined-time controller is induced. Then, a morphing information-driven (MI-driven) event-triggering mechanism (ETM) is developed to save the system resources. For investigation, the Lyapunov theory is adopted to prove the stability, and several simulations validate the performance of the proposed control strategy. The contribution is summarized as follows: 1) fast attitude-tracking is ensured for HMVs by developing predefined-time controller; 2) the proposed ETM could actively utilize the morphing information to adjust the triggering policy, which is a distinctive development. It is emphasized that introducing the MI into the ETM could further preserve the system resource in continuous morphing stages.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 110940"},"PeriodicalIF":5.8,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219740","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":"Facility pressure effects on thrust measurement of micronozzles and thrust correction for space applications","authors":"Keita Nishii","doi":"10.1016/j.ast.2025.111016","DOIUrl":"10.1016/j.ast.2025.111016","url":null,"abstract":"<div><div>Accurate thrust estimation of low-Reynolds-number micronozzles is essential for designing reliable micropropulsion systems. However, ground-based measurements are influenced by facility pressure effects, which reduce the measured thrust due to rarefied gas interactions between the nozzle jet plume and the ambient gas. This study aims to identify the key parameters of and develop a thrust correction model for the facility pressure effect, grounded in a gas depletion framework. Direct simulation Monte Carlo simulation reveals that thrust decreases as the inverse nozzle pressure ratio increases, with this reduction varying significantly based on the throat Reynolds number. In terms of nozzle geometry, the divergence angle and expansion ratio had minimal effects, while the exit wall radius had a substantial impact on thrust reduction. Although gas species influenced specific impulse efficiency, the thrust reduction caused by the facility pressure remained nearly independent of gas species. Based on the simulation results, the correction factor in the gas depletion model was empirically formulated. The model accurately predicted thrust reductions of up to 50 %, with a maximum estimation error of 2.2 %. This approach allows for precise prediction of in-space nozzle performance from ground test data, supporting the operational reliability of small spacecraft.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 111016"},"PeriodicalIF":5.8,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265734","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":"Analysis and modelling of rotating detonation engine refill structures","authors":"Quentin Michalski ,&nbsp;John Grunenwald ,&nbsp;Venkat Athmanathan ,&nbsp;James Braun","doi":"10.1016/j.ast.2025.110970","DOIUrl":"10.1016/j.ast.2025.110970","url":null,"abstract":"<div><div>This study presents a novel low-order model for the fresh gas region in Rotating Detonation Engines (RDEs), developed and verified against high-fidelity 2D computational fluid dynamics (CFD) simulations. The fresh gas model provides direct closure for the refill mechanism and can be readily implemented in other 1D or 2D RDE models. The model captures the spatially varying pressure and thermodynamic structure of the refresh layer via a linearised Method of Characteristics (MOC), accounting for the expansion process in the slip line and incorporating mass flow conservation. For the first time, the model incorporates a fully analytical treatment of stagnation pressure losses within the fresh gas layer, primarily attributed to spatial gradients within the injection region. The influence of front lift and associated fresh gas recirculation is also analysed, demonstrating a significant impact on the detonation front height and pressure gain. The model exhibits strong agreement with CFD data across multiple operating conditions, providing a practical tool for predicting spatially resolved refill conditions and enabling a more accurate prediction of post-detonation flow behavior in canonical air-breathing and rocket RDE systems compared with existing models.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 110970"},"PeriodicalIF":5.8,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265737","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":"Online entry trajectory planning with simultaneous constraints on terminal full-states, flight time and no-fly zones","authors":"Changzhu Wei ,&nbsp;Yankun Zhang ,&nbsp;Jialun Pu ,&nbsp;Feng Zhang","doi":"10.1016/j.ast.2025.111019","DOIUrl":"10.1016/j.ast.2025.111019","url":null,"abstract":"<div><div>The integration of terminal full-state constraints, flight time constraints, and no-fly zone constraints makes the reentry trajectory planning a highly underactuated planning problem, where profile-based methods are inefficient and analytical methods struggle to satisfy multi-constraints. To achieve both high adaptability to complex constraints and low computation cost, this paper proposes a novel trajectory planning approach. The approach begins by generating an optimal no-fly-zone-avoiding path using a directed graph-based strategy. Subsequently, a dual-layer longitudinal profile is constructed upon the path, comprising a velocity-altitude sub-profile and an altitude versus range-to-go sub-profile. This dual-profile structure facilitates the analytical satisfaction of terminal constraints on altitude, velocity, and flight path angle. Furthermore, the flight time integral is transformed into a fast algebraic expression via Chebyshev polynomial approximation, enabling explicit and low-cost time control. For lateral trajectory generation, a method based on bank reversal timing optimization is developed with the use of the longitudinal profile, where terminal constraints on latitude, longitude, and heading angle are satisfied by adjusting bank reversal timing. Numerical simulations validate the feasibility and robustness of the proposed method for trajectory planning of hypersonic glide vehicles (HGVs) operating in complex environments.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 111019"},"PeriodicalIF":5.8,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265743","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":"Prediction of shock and boundary layer interaction in supersonic/hypersonic flow over a compression ramp using deep neural networks","authors":"Yuan Jia ,&nbsp;Zhengtong Li ,&nbsp;Chi Zhang ,&nbsp;Hao Ma ,&nbsp;Jiaao Hao ,&nbsp;Chih-Yung Wen","doi":"10.1016/j.ast.2025.110976","DOIUrl":"10.1016/j.ast.2025.110976","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study investigates the accurate prediction of supersonic and hypersonic flow fields over a compression ramp using deep neural networks. While deep learning methods have demonstrated effectiveness in flow field prediction, challenges remain in resolving fine-scale features characteristic of supersonic and hypersonic flows, such as &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;k&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;W&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;L&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (SWBLI). To address this, a flow field modeling method using &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (ViT) and U-Net &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;l&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;l&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;l&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;k&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (CNN) based on the coordinate transformation is employed. This strategy reduces information loss near the wall region and enhances the prediction accuracy of boundary layer flow fields. Meanwhile, a comparative analysis between the two surrogate models reveals that ViT outperforms U-Net CNN applied in this study, achieving reductions in errors of 72.6 % and 69.5 % for streamwise and normal velocities, respectively. Furthermore, physics-informed loss functions – including wavelet loss and pressure gradient-related loss – are introduced to improve prediction accuracy in shock-induced boundary layer separation and reattachment regions. The results demonstrate that models incorporating physics-informed losses capture more detailed flow features; however, discontinuities between adjacent patches still impose limitations on accuracy. To overcome this, the proposed patch prior method effectively addresses patch discontinuity issues, enabling accurate wall pressure predictions while maintaining a separation length error of approximately 6 % compared to &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;l&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;F&lt;/mi&gt;&lt;mi&gt;l&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mi&gt;y&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;s&lt;/","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 110976"},"PeriodicalIF":5.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265739","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":"Effects of the fluidization modes on conveying characteristics in the powder fueled ramjets via a multiple state model of the dense powder flows","authors":"Shilin Gao,&nbsp;Haibin Zhang,&nbsp;Bofeng Bai","doi":"10.1016/j.ast.2025.111024","DOIUrl":"10.1016/j.ast.2025.111024","url":null,"abstract":"<div><div>As the core component of powder fueled ramjets, accurately characterizing the dense powder conveying behaviors is crucial for the design of powder feeding system and for achieving the ramjet's energy control and multi-mode operations. Limited by the testing approaches for dense powders, a modified two-fluid model (TFM), integrating <em>μ</em>(<em>I</em>) rheology theory and Hooke’s law, has been constructed in this paper to depict the multiple states and nonlinear evolutions of dense granular flows within the powder feeding systems. And a piston dynamic mesh boundary, consistent with the actual process, was constructed. By using the modified TFM, the effects of fluidization modes on conveying characteristics were explored, revealing the nonlinear correlation between the powder rheological properties and the fluctuation of output flow rate. Furthermore, the impacts of fluidizing gas injection direction and the contraction angle of the storage tank on the conveying performance were investigated. The findings have indicated that the gas cavitation instability led to flow rate fluctuations, while reducing the contraction angle of the storage tank enhanced the output flow rate and solid-gas ratio. This study provides a novel approach and valuable insights for the designing propellant feeding systems, contributing significantly to the development of stable and controllable powdered fuel feeding technology for powder fueled ramjets.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 111024"},"PeriodicalIF":5.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265914","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":"NeRF-based simultaneous pose estimation and 3D reconstruction for non-cooperative space target","authors":"Dazhuang Yang ,&nbsp;Yizhai Zhang ,&nbsp;Ge Yu ,&nbsp;Jiafu Jiao ,&nbsp;Panfeng Huang ,&nbsp;Binglu Wang","doi":"10.1016/j.ast.2025.111010","DOIUrl":"10.1016/j.ast.2025.111010","url":null,"abstract":"<div><div>Accurate pose estimation and 3D reconstruction of Non-Cooperative Space Targets (NCSTs) are critical for proximity operations in active debris removal and on-orbit servicing. In this paper, we propose a novel NeRF-based Simultaneous Pose Estimation and 3D Reconstruction (SPAR) framework to address the challenges of efficiency and reliability in traditional point-based methods. Our framework contains three key components: a multi-resolution hash encoder to reduce computational cost, a 2D keyframe feature enhancement to guide view generalization, and a direct photometric constraint to stabilize pose estimation. Furthermore, the proposed framework is evaluated on a newly constructed Spacecraft Pose Estimation and 3D Reconstruction Dataset (SPARD), comprising both synthetic and real RGB-D images and the experimental results demonstrate its effectiveness. Our framework achieves real-time processing at 51 Hz with a pose estimation accuracy of 1.26 cm translation error and 0.97° rotation error. In 3D reconstruction, the framework updates at a frequency of 32 Hz, and attains a peak signal-to-noise ratio of at least 40 dB for RGB-D images. The results show improvements over traditional and NeRF-based baselines, validating its applicability to space missions with NCST. The source code and dataset are available at <span><span>https://dazhuang-yang.github.io/</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"168 ","pages":"Article 111010"},"PeriodicalIF":5.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266487","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}