Aerospace

20 pages, 5673 KiB

Open AccessArticle

Unsteady Numerical Investigation into the Impact of Isolator Motion on High-Mach-Number Inlet Restart via Throat Adjustment

by Hongyu Tang, Yuan Liu, Yongfei Cao, Liangjie Gao and Zhansen Qian

Aerospace 2025, 12(5), 450; https://doi.org/10.3390/aerospace12050450 - 21 May 2025

Viewed by 147

Abstract

This paper focuses on exploring the variable throat-assisted restart method for high-Mach-number inlets. A two-dimensional adjustable throat hypersonic inlet was designed, and unsteady numerical simulations were carried out on its restart process, which was triggered by unstart induced by excessive back pressure and [...] Read more.

This paper focuses on exploring the variable throat-assisted restart method for high-Mach-number inlets. A two-dimensional adjustable throat hypersonic inlet was designed, and unsteady numerical simulations were carried out on its restart process, which was triggered by unstart induced by excessive back pressure and assisted by throat adjustment. The Chimera grid technique was used for grid generation, and the simulations were performed on the ARI_CFD platform. Results show that during the throat adjustment restart process, different flow states emerged with an increase in adjustment height. Specifically, when the adjustment height was too low, an unstarted flow state existed; within a specific height range (with lower and upper critical heights of 1.190 and 1.196, respectively, in this study), a fully restarted flow state occurred; and when the height was too high, an off-design flow state induced by the separation region in the internal contraction section occurred. The geometric adjustment time and throat adjustment angle also had a significant impact on the restart process. Shorter adjustment times and larger adjustment angles expanded the adjustment interval for full restart, as the rotation of the isolator helps reduce the resistance of the separation bubble’s downstream movement on the compression surface, thereby facilitating the full restart of the inlet. Full article

(This article belongs to the Special Issue Innovation and Challenges in Hypersonic Propulsion)

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34 pages, 155018 KiB

Open AccessArticle

ACCORD: A Formal Model for the Digitalization and Automation of Drone Coordination Processes

by Enric Pastor, Miquel Macias, Yeray Martin, Albert Sanchez and Cristina Barrado

Aerospace 2025, 12(5), 449; https://doi.org/10.3390/aerospace12050449 - 20 May 2025

Viewed by 194

Abstract

This paper introduces ACCORD, a support platform designed to digitalize and automate the coordination processes required by the current drone regulatory framework. Drone operators must complete several coordination actions with both aeronautical and non-aeronautical entities. Traditional aeronautical coordination actions relate to the need [...] Read more.

This paper introduces ACCORD, a support platform designed to digitalize and automate the coordination processes required by the current drone regulatory framework. Drone operators must complete several coordination actions with both aeronautical and non-aeronautical entities. Traditional aeronautical coordination actions relate to the need to access protected airspace volumes around airports. Additional coordination should be established with smaller aeronautical infrastructures, like small aerodromes and heliports, which are not surrounded by any type of pre-defined airspace. Therefore, drone-specific protection volumes have been created. ACCORD enables a single entry point for all the necessary coordination processes for drone operators and infrastructure managers. The objective is to minimize the number of required actions, guarantee full traceability of the process, maximize access to the relevant information, automate the processes as much as possible, and maintain a high level of flexibility to support all coordination processes. After coordination is established, it moves from the strategic/planning phase to the actual execution phase. ACCORD also enables a communication mechanism between the drone operators and the aeronautical infrastructures to extend the coordination to the actual mission execution. ACCORD is currently being tested by some of the most relevant actors in the Catalan drone ecosystem. The current version of the system provides support for all types of aeronautical infrastructures (heliports, aerodromes, and airports) and management duality for situations in which the infrastructure manager and the aeronautical service provider coexist. Full article

(This article belongs to the Special Issue Advances in Air Traffic and Airspace Control and Management (2nd Edition))

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17 pages, 2913 KiB

Open AccessArticle

On-Orbit Functional Verification of Combustion Science Experimental System in China Space Station

by Pingping Zhao, Xiaowu Zhang, Yu Fang, Hailong Wu, Xiaofang Yang and Huilong Zheng

Aerospace 2025, 12(5), 448; https://doi.org/10.3390/aerospace12050448 - 20 May 2025

Viewed by 183

Abstract

We demonstrated the development, implementation, and functional verification of the combustion science payload deployed on the China Space Station. The Combustion Science Experiment System (CSES) integrated seven subsystems and modular plugins to address the major challenges facing microgravity combustion research, including the lack [...] Read more.

We demonstrated the development, implementation, and functional verification of the combustion science payload deployed on the China Space Station. The Combustion Science Experiment System (CSES) integrated seven subsystems and modular plugins to address the major challenges facing microgravity combustion research, including the lack of long-duration experimental platforms, spatial constraints, and safety risks. Through on-orbit testing, the core functions of the CSES under microgravity conditions were validated, including gas supply, ignition, combustion diagnostic, exhaust purification, and emission. The system achieved autonomous experiment execution by ground-injected commands. Data from on-orbit methane combustion experiments demonstrated that the CSES was capable of stably supplying oxygen and fuel gas at a preset flow rate, real-time combustion diagnosis, and provided high-resolution flame image. Effectively exhaust gas purification and emission control of the CSES have also been tested and verified. It provides a safe, reliable, and stable microgravity environment of long-duration research for the combustion science and the development of spacecraft fire safety technology. Full article

(This article belongs to the Section Astronautics & Space Science)

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30 pages, 4946 KiB

Open AccessArticle

Frequency Assignment for Aviation Navigation Stations Based on an Improved Multi-Objective Genetic Local Search Algorithm

by Boyang Hao, Yajun Xu, Ke Gong, Tianlu Gao, Yiling Gui, Minghui Liu and Qiang Zhang

Aerospace 2025, 12(5), 447; https://doi.org/10.3390/aerospace12050447 - 20 May 2025

Viewed by 283

Abstract

With the rapid development of both commercial and general aviation, the frequency assignment problem for aviation navigation stations has become increasingly important. This paper presents a general algorithm for frequency assignment at individual aviation navigation stations. Subsequently, a frequency assignment model for multiple [...] Read more.

With the rapid development of both commercial and general aviation, the frequency assignment problem for aviation navigation stations has become increasingly important. This paper presents a general algorithm for frequency assignment at individual aviation navigation stations. Subsequently, a frequency assignment model for multiple civil aviation navigation stations is established to address large-scale frequency allocation challenges. To overcome the limitations of traditional multi-objective genetic algorithms, such as slow convergence speed and susceptibility to local optima, this study proposes several improved algorithms, including the multi-objective genetic algorithm with randomly assigned weights, the multi-objective genetic local search algorithm, and an improved multi-objective genetic local search algorithm, while optimizing key algorithm parameters. The problem involves multiple objectives, including minimizing interference in frequency assignment and reducing the total number of assigned frequencies. Experimental results demonstrate that the proposed improved multi-objective genetic algorithms—especially IMOGLSA-II—effectively address the frequency assignment problem for aviation navigation stations, achieving notable improvements in solution quality, convergence speed, and stability compared with other multi-objective genetic algorithms. In particular, although the time complexity of the proposed algorithm is slightly higher due to the incorporation of local search mechanisms, it exhibits clear advantages in reducing parameter sensitivity, simplifying algorithm structure, and enhancing engineering applicability. These characteristics make the proposed method not only well-suited to the static and constrained nature of aviation frequency assignment, but also more practical and effective than other mainstream multi-objective optimization algorithms in similar engineering scenarios. Furthermore, the proposed method offers a reliable approach that can be extended to other static frequency assignment problems and broader classes of multi-objective optimization tasks. Full article

(This article belongs to the Section Air Traffic and Transportation)

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23 pages, 8506 KiB

Open AccessArticle

Destructive and Non-Destructive Analysis of Lightning-Induced Damage in Protected and Painted Composite Aircraft Laminates

by Audrey Bigand, Christine Espinosa and Jean-Marc Bauchire

Aerospace 2025, 12(5), 446; https://doi.org/10.3390/aerospace12050446 - 19 May 2025

Viewed by 242

Abstract

The use of CFRP composite increased significantly since the last 40 years for aircraft structure. Unfortunately, such structures are subjected to significant damages if struck by lightning compared to metallic structure. This is mainly due to the low conductivity of this material, which [...] Read more.

The use of CFRP composite increased significantly since the last 40 years for aircraft structure. Unfortunately, such structures are subjected to significant damages if struck by lightning compared to metallic structure. This is mainly due to the low conductivity of this material, which cannot evacuate the current without high Joule heating. Lightning strike-induced damage in a composite laminate is composed of in-depth delamination, fibre breakage, and resin deterioration due to the surface explosion and the core current flow linked to interaction of the arc with the surface. But very rare previous studies dedicated to the analysis of damage as a direct effect of lightning have considered the spurious effect of the paint that always covers real aeronautic structures neither on the thermal nor the mechanical loads that are the root cause of these damages. We present in this paper a coupled non-destructive and destructive damage analysis to support the proposition of damage scenarios depending on the presence and thickness of the paint. The mechanical and thermal sources contribution in the global loading on the core damage is discussed, which confirms previous studies’ analysis and modelling and is in accordance with existing works in the literature. Full article

(This article belongs to the Section Astronautics & Space Science)

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17 pages, 8134 KiB

Open AccessArticle

Simulations and Analyses of the Influence of a Vacuum Back-Pressure Environment on Laser Ablation Thrusters

by Ming Wen, Baosheng Du, Haichao Cui and Jianhui Han

Aerospace 2025, 12(5), 445; https://doi.org/10.3390/aerospace12050445 - 19 May 2025

Viewed by 203

Abstract

The study of thruster plume flow fields can yield a series of thruster performance parameters such as thrust effect, spacecraft plume contamination, etc., which is of great significance for thruster development. The paper presents a physical simulation model of a laser thruster under [...] Read more.

The study of thruster plume flow fields can yield a series of thruster performance parameters such as thrust effect, spacecraft plume contamination, etc., which is of great significance for thruster development. The paper presents a physical simulation model of a laser thruster under a vacuum back-pressure environment. Through the finite difference method and the Direct Simulation Monte Carlo (DSMC) calculation method, based on the actual laser ablation thruster structure and working mode, the changes in the flow-field distribution in the laser thruster plume under different vacuum back-pressure conditions are obtained. The influence of different vacuum back-pressure conditions on the plume density, pressure, temperature, and velocity field of the thruster was verified through physical experiments, and the evolution of the plume flow field during the laser ablation of a polyamide glycidyl ether (GAP) solid target material was analyzed in detail. The simulation results are in good agreement with the test results, and the deviation between the simulated data and the test data from 0 to 3000 ns is less than 10.4%. This study presents a foundation for a prediction model of laser ablation thrusters under vacuum environments and provides an important reference for ground tests and in-orbit applications of satellite laser propulsion systems. Full article

(This article belongs to the Special Issue Laser Propulsion Science and Technology (2nd Edition))

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33 pages, 2191 KiB

Open AccessArticle

Aircraft Routing and Crew Pairing Solutions: Robust Integrated Model Based on Multi-Agent Reinforcement Learning

by Chengjin Ding, Yuzhen Guo, Jianlin Jiang, Wenbin Wei and Weiwei Wu

Aerospace 2025, 12(5), 444; https://doi.org/10.3390/aerospace12050444 - 16 May 2025

Viewed by 226

Abstract

Every year, airlines invest considerable resources in recovering from irregular operations caused by delays and disruptions to aircraft and crew. Consequently, the need to reschedule aircraft and crew to better address these problems has become pressing. The airline scheduling problem comprises two stages—that [...] Read more.

Every year, airlines invest considerable resources in recovering from irregular operations caused by delays and disruptions to aircraft and crew. Consequently, the need to reschedule aircraft and crew to better address these problems has become pressing. The airline scheduling problem comprises two stages—that is, the Aircraft-Routing Problem (ARP) and the Crew-Pairing Problem (CPP). While the ARP and CPP have traditionally been solved sequentially, such an approach fails to capture their interdependencies, often compromising the robustness of aircraft and crew schedules in the face of disruptions. However, existing integrated ARP and CPP models often apply static rules for buffer time allocation, which may result in excessive and ineffective long-buffer connections. To bridge these gaps, we propose a robust integrated ARP and CPP model with two key innovations: (1) the definition of new critical connections (NCCs), which combine structural feasibility with data-driven delay risk; and (2) a spatiotemporal delay-prediction module that quantifies connection vulnerability. The problem is formulated as a sequential decision-making process and solved via a novel multi-agent reinforcement learning algorithm. Numerical results demonstrate that the novel method outperforms prior methods in the literature in terms of solving speed and can also enhance planning robustness. This, in turn, can enhance both operational profitability and passenger satisfaction. Full article

(This article belongs to the Section Air Traffic and Transportation)

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11 pages, 2474 KiB

Open AccessArticle

Aerodynamic Optimization of Airfoil in Wide Range of Operating Conditions Based on Reinforcement Learning

by Yiting Zhang, Jiaqi Luo, Yao Zheng and Yaolong Liu

Aerospace 2025, 12(5), 443; https://doi.org/10.3390/aerospace12050443 - 16 May 2025

Viewed by 235

Abstract

Airfoil aerodynamic design represents an essential domain in aircraft development, where the pursuit of advanced and intelligent optimization strategies is important for achieving significant advancements. In this paper, we demonstrate the effectiveness and versatility of reinforcement learning (RL)-based optimization methods in enhancing aerodynamic [...] Read more.

Airfoil aerodynamic design represents an essential domain in aircraft development, where the pursuit of advanced and intelligent optimization strategies is important for achieving significant advancements. In this paper, we demonstrate the effectiveness and versatility of reinforcement learning (RL)-based optimization methods in enhancing aerodynamic performance for both transonic and supersonic airfoils. We introduced a novel methodology using RL to optimize airfoil designs, leveraging ADflow as the aerodynamic solver and constructing an RL environment where Class-Shape Transformation (CST) parameters describe the airfoil geometry, transforming it into a finite state variable. Key flow field features, especially shock waves, were incorporated to guide the optimization process, enabling the RL model to iteratively improve designs based on real-time feedback from simulations. Applied to transonic airfoils, this method yielded remarkable results, including a 70.20% increase in the lift-to-drag ratio for one airfoil, with consistent improvements across various initial geometries and flight conditions. Extending to the NASA SC(2)-0404 supersonic airfoil, the optimized design achieved significant geometric changes that resulted in a 6.25% increase in the lift-to-drag ratio, with improvements ranging from 4.90% to 25.46% across different lift coefficients. These findings highlight the robustness and adaptability of RL techniques in addressing the unique challenges of both transonic and supersonic aerodynamics while maintaining structural integrity. Full article

(This article belongs to the Special Issue Overall Aircraft Design for New Airframe Technologies, New Energy Systems and New Operations)

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28 pages, 1810 KiB

Open AccessArticle

Airborne Network Information Security Risk Assessment Method Based on Improved STPA-TOPSIS

by Kenian Wang, Mingluan Zhang, Yuan Hong, Jie Bai and Lizhe Zhang

Aerospace 2025, 12(5), 442; https://doi.org/10.3390/aerospace12050442 - 16 May 2025

Viewed by 150

Abstract

This study addresses threat scenario identification and quantitative evaluation in the context of the information security risk assessment process for airborne networks. A method integrating an improved system-theoretic process analysis (STPA) and the technique for order preference by similarity to an ideal solution [...] Read more.

This study addresses threat scenario identification and quantitative evaluation in the context of the information security risk assessment process for airborne networks. A method integrating an improved system-theoretic process analysis (STPA) and the technique for order preference by similarity to an ideal solution (TOPSIS) is proposed. A safety control interaction structure is first established based on the system-level loss definition to identify unsafe control actions and derive STPA-Sec threat conditions. Then, the opinion aggregation method based on the weakest t-norm is introduced to address the uncertainty from insufficient expert consensus and opinion deviation. To address the intrinsic correlations among evaluation indicators, the criteria importance through intercriteria correlation (CRITIC) method is applied to determine indicator weights. These weights are subsequently incorporated into the TOPSIS framework to assess the identified threat scenarios. Comparative analysis confirms the effectiveness of the proposed approach. The results show that the improved STPA-TOPSIS method enables the reliable identification of security threats in airborne networks and supports the prioritization of threat scenarios by severity, facilitating the implementation of targeted mitigation strategies. Full article

(This article belongs to the Collection Avionic Systems)

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19 pages, 4310 KiB

Open AccessArticle

The Calculation and Optimization Methodology of Repairable Elements of a UAV Structure

by Wojciech Skarka, Sergiy Kurennov, Kostiantyn Barakhov, Fedir Gagauz, Olesia Maksymovych and Oleksii Vambol

Aerospace 2025, 12(5), 441; https://doi.org/10.3390/aerospace12050441 - 16 May 2025

Viewed by 166

Abstract

A novel approach to the calculation and optimization methodology of repairable elements of unmanned aerial vehicle (UAV) structures using pre-cured composite patches is proposed. These patches are glued to the damaged structure with adhesives filled with short fibers or particulate fillers. Compared with [...] Read more.

A novel approach to the calculation and optimization methodology of repairable elements of unmanned aerial vehicle (UAV) structures using pre-cured composite patches is proposed. These patches are glued to the damaged structure with adhesives filled with short fibers or particulate fillers. Compared with conventional repair procedures (in which composite prepregs or wet lay-up are used), the suggested method allows damaged UAV structures to be repaired relatively quickly in field conditions without the need for a vacuum or special equipment. In most scientific studies on this problem, significant attention is devoted to the investigation of rectangular patches used for reinforcing plates that have defects such as cracks and damage. This study focuses on the potential application of circular patches for reinforcing plates with defects or damage and includes further parametric optimization of the geometric parameters of the patch. A fundamental approach to the topological and structural optimization of adhesive bonding, along with an experimental study of adhesive properties, has been combined into a single model. This model includes the optimization of the shape and structure of patches for bonded repair, allowing for changes in adhesive thickness to restore the load-carrying capacity of the structure. The simulation and analysis of the results of the renovation of damaged structures for double-sided and single-sided repaired elements of the UAV structure were performed. Full article

(This article belongs to the Section Aeronautics)

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14 pages, 2013 KiB

Open AccessArticle

Lab-Scale Thermal Decomposition of Hydrogen Peroxide as Green Propellant over Low-Cost Catalysts Based on Copper Deposited on Different Supports

by Imane Remissa, Ahmed E. S. Nosseir, Amit Tiwari, Ahmed Bachar, Assia Mabrouk and Rachid Amrousse

Aerospace 2025, 12(5), 440; https://doi.org/10.3390/aerospace12050440 - 15 May 2025

Viewed by 274

Abstract

The thermal decomposition of hydrogen peroxide (H₂O₂) as a promising green propellant was performed over free-noble metallic-based catalysts deposited on abundant supports. A 30% (w/w) H₂O₂ liquid was decomposed over 1 wt.% [...] Read more.

The thermal decomposition of hydrogen peroxide (H₂O₂) as a promising green propellant was performed over free-noble metallic-based catalysts deposited on abundant supports. A 30% (w/w) H₂O₂ liquid was decomposed over 1 wt.% of copper-based catalysts deposited on three different supports: γ-alumina, graphite and monocrystal clay. In this research work, the catalytic performance of the thermal decomposition of H₂O₂ was carried out by measuring the differential pressure (ΔP) versus time at initial constant temperatures and, for the first time, by the DTA-TG technique and by the DIP-MS technique at atmospheric pressure. The obtained preliminary results showed that copper deposited on alumina and on graphite are promising catalysts for the decomposition of the H₂O₂ liquid propellant. Moreover, the natural clay can be valorized on the thermal decomposition of H₂O₂ due to its high resistivity and high surface area. The N₂-physisorption technique and scanning electron microscopy technique were used to characterize the effect of the texture properties on the decomposition and to understand the morphological characteristics of the catalyst. Full article

(This article belongs to the Special Issue Green Propulsion: Present Solutions and Perspectives for Powering Environmentally Friendly Space Missions (2nd Edition))

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18 pages, 3838 KiB

Open AccessArticle

Wind Tunnel Process Mach Number Prediction Based on Modal, Stage, and Intra-Stages Three-Layer Partitioning

by Haixuan Yuan, Jin Guo, Wenshan Yu and Luping Zhao

Aerospace 2025, 12(5), 439; https://doi.org/10.3390/aerospace12050439 - 15 May 2025

Viewed by 181

Abstract

The wind tunnel experiment process is a nonlinear process with complex process characteristics. It is the primary task to master the key physical parameters and performance evaluation criteria during its operation. Aiming at the characteristics of multi-mode, multi-stage and intra-stage changes in the [...] Read more.

The wind tunnel experiment process is a nonlinear process with complex process characteristics. It is the primary task to master the key physical parameters and performance evaluation criteria during its operation. Aiming at the characteristics of multi-mode, multi-stage and intra-stage changes in the wind tunnel process, this paper proposes a Mach number prediction method based on mode, stage and intra-stage division. Firstly, mode division is carried out. The K-means clustering method is mainly used to cluster process data. The elbow rule is used to determine the cluster number K. The Mach number is used as the index variable to divide the process into phases, and divide the phases into stable parts and transitional parts according to different process characteristics. Considering the nonlinearity of the data, a kernel partial least squares prediction model is constructed for the stable process. Considering the dynamic characteristics of data, a dynamic partial least squares prediction model is constructed for the transitional process. The proposed method has been applied to multi-stage nonlinear wind tunnel experiments, and satisfactory results have been obtained. Full article

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26 pages, 4222 KiB

Open AccessArticle

Imitation-Reinforcement Learning Penetration Strategy for Hypersonic Vehicle in Gliding Phase

by Lei Xu, Yingzi Guan, Jialun Pu and Changzhu Wei

Aerospace 2025, 12(5), 438; https://doi.org/10.3390/aerospace12050438 - 15 May 2025

Viewed by 213

Abstract

To enhance the penetration capability of hypersonic vehicles in the gliding phase, an intelligent maneuvering penetration strategy combining imitation learning and reinforcement learning is proposed. Firstly, a reinforcement learning penetration model for hypersonic vehicles is established based on the Markov Decision Process (MDP), [...] Read more.

To enhance the penetration capability of hypersonic vehicles in the gliding phase, an intelligent maneuvering penetration strategy combining imitation learning and reinforcement learning is proposed. Firstly, a reinforcement learning penetration model for hypersonic vehicles is established based on the Markov Decision Process (MDP), with the design of state, action spaces, and composite reward function based on Zero-Effort Miss (ZEM). Furthermore, to overcome the difficulties in training reinforcement learning models, a truncated horizon method is employed to integrate reinforcement learning with imitation learning at the level of the optimization target. This results in the construction of a Truncated Horizon Imitation Learning Soft Actor–Critic (THIL-SAC) intelligent penetration strategy learning model, enabling a smooth transition from imitation to exploration. Finally, reward shaping and expert policies are introduced to enhance the training process. Simulation results demonstrate that the THIL-SAC strategy achieves faster convergence compared to the standard SAC method and outperforms expert strategies. Additionally, the THIL-SAC strategy meets real-time requirements for high-speed penetration scenarios, offering improved adaptability and penetration performance. Full article

(This article belongs to the Section Aeronautics)

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23 pages, 2135 KiB

Open AccessArticle

Lessons Learned from Official Airline Reports of Onboard Fumes and Smoke

by Judith T. L. Anderson

Aerospace 2025, 12(5), 437; https://doi.org/10.3390/aerospace12050437 - 14 May 2025

Viewed by 554

Abstract

The author reviewed and classified maintenance reports that cited smoke, odor, or fumes (SOFs) that US airlines sent to the FAA over four years between 2018 and 2023. The US fleet composition was also calculated to put the number of SOF reports on [...] Read more.

The author reviewed and classified maintenance reports that cited smoke, odor, or fumes (SOFs) that US airlines sent to the FAA over four years between 2018 and 2023. The US fleet composition was also calculated to put the number of SOF reports on each aircraft type in perspective. “Fume events” (engine oil or hydraulic fluid) were the most common type of onboard SOFs reported by US airlines (43%), followed by electrical (20%), and fans (6.1%). During these years, A320fam aircraft made up 20% of the US fleet but 80% of the reported fume events. Conversely, B737fam aircraft made up 27% of the US fleet but only 3.0% of the reported fume events. Aircraft design features, airline reporting practices, and maintenance procedures that may contribute to these differences were reviewed. Pilots were most likely to document a fume event during descent (47%) and takeoff/climb (19%). The A320fam, MD80fam, A330, and ERJ140-145 aircraft were over-represented in other types of SOFs reports. Airline narratives show that the APU can be the primary source of oil/hydraulic fumes, even when it is not operating. Additionally, failure to find the source of fumes, rectify it, and clean any secondary sources of fumes can cause repeat events. Full article

(This article belongs to the Special Issue Aircraft Design (SI-7/2025))

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18 pages, 28516 KiB

Open AccessArticle

Aircraft Wing Design Against Bird Strike Using Metaheuristics

by Vanessa Timhede, Silvia Timhede, Seksan Winyangkul and Suwin Sleesongsom

Aerospace 2025, 12(5), 436; https://doi.org/10.3390/aerospace12050436 - 13 May 2025

Viewed by 358

Abstract

Bird strikes pose a significant threat to aviation safety, particularly affecting the wing structures of aircraft. This research aims to design and analyze the impact of bird strikes on wing structures using response surface method and metaheuristics (MHs), which are used to explore [...] Read more.

Bird strikes pose a significant threat to aviation safety, particularly affecting the wing structures of aircraft. This research aims to design and analyze the impact of bird strikes on wing structures using response surface method and metaheuristics (MHs), which are used to explore various risk minimization and damage mitigation techniques. The optimization problem is the minimization of the maximum von Mises stress of aircraft wing structure against bird strike that is subject to displacement and stress constraints. The design variables include skin and rib thickness, as well as sweep angle. Difficulty due to embedded bird strike simulation and optimization design can be alleviated using a response surface method (RSM). The regression technique in the RSM of the data can reach our goal of model fitting with a higher R² until 0.9951 and 0.9919 are obtained for the displacement and von Mises stress model, respectively. The response surface function of the displacement and von Mises stress are related to skin thickness, while sweep angles rather than rib thickness have a greater impact on both design variables. The optimized design of the design variables is performed using MHs, which are TLBO, JADE, and PBIL. The comparative result of MHs can conclude that the PBIL outperformed others in all descriptive statistics. The optimized design results revealed that the optimum solution can release better energy due to bird strike with the highest limit of skin thickness, moderate rib thickness, and less than half of the sweep angle. The results are in accordance with the response surface function analysis. In conclusion, the optimized design of the aircraft wing structure against bird strike can be accomplished with our proposed technique. Full article

(This article belongs to the Special Issue Environmental Influences on Aircraft Aerodynamics)

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21 pages, 9421 KiB

Open AccessArticle

Temporal-Sequence Offline Reinforcement Learning for Transition Control of a Novel Tilt-Wing Unmanned Aerial Vehicle

by Shiji Jin and Wenjie Zhao

Aerospace 2025, 12(5), 435; https://doi.org/10.3390/aerospace12050435 - 13 May 2025

Viewed by 332

Abstract

A newly designed tilt-wing unmanned aerial vehicle (Tilt-wing UAV) requires a unified control strategy across rotary-wing, fixed-wing, and transition modes, introducing significant challenges. Existing control strategies typically rely on accurate modeling or extensive parameter tuning, which limits their adaptability to dynamically changing flight [...] Read more.

A newly designed tilt-wing unmanned aerial vehicle (Tilt-wing UAV) requires a unified control strategy across rotary-wing, fixed-wing, and transition modes, introducing significant challenges. Existing control strategies typically rely on accurate modeling or extensive parameter tuning, which limits their adaptability to dynamically changing flight configurations. Although online reinforcement learning algorithms offer adaptability, they depend on real-world exploration, posing considerable safety and cost risks for safety-critical UAV applications. To address this challenge, we propose Temporal Sequence Constrained Q-learning (TSCQ), an offline RL framework that integrates an encoder–decoder with recurrent networks to capture temporal dependencies. The policy is further constrained within an offline dataset collected via hardware-in-the-loop simulation using a variational autoencoder, and a sequence-level prediction mechanism is introduced to ensure temporal consistency across action trajectories, thereby mitigating extrapolation error while preserving data fidelity. Experimental results demonstrate that TSCQ significantly outperforms gain scheduling, Model Predictive Control (MPC), and Batch-Constrained Q-learning (BCQ), reducing the RMSE of pitch angle by up to 53.3% and vertical velocity RMSE by approximately 33%. These findings underscore the potential of data-driven, safety-aware offline RL paradigms to enable robust and generalizable control strategies for tilt-wing UAVs. Full article

(This article belongs to the Section Aeronautics)

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26 pages, 5234 KiB

Open AccessArticle

An Image and State Information-Based PINN with Attention Mechanisms for the Rapid Prediction of Aircraft Aerodynamic Characteristics

by Yiduo Kan, Xiangdong Liu and Haikuo Liu

Aerospace 2025, 12(5), 434; https://doi.org/10.3390/aerospace12050434 - 13 May 2025

Viewed by 217

Abstract

Prediction of aircraft aerodynamic parameters is crucial for aircraft design, yet traditional computational fluid dynamics methods remain time-consuming and labor-intensive. This work presents a novel model, the image and state information-based attention-enhanced physics-informed neural network (ISA-PINN), which significantly improves prediction accuracy. Our model [...] Read more.

Prediction of aircraft aerodynamic parameters is crucial for aircraft design, yet traditional computational fluid dynamics methods remain time-consuming and labor-intensive. This work presents a novel model, the image and state information-based attention-enhanced physics-informed neural network (ISA-PINN), which significantly improves prediction accuracy. Our model incorporates the following innovations: the designed attention module dynamically extracts hidden features from pattern data while selectively focusing on relevant dimensions of target information. Meanwhile, the image-information fusion module combines multi-scale geometric features derived from aircraft images to enhance the overall prediction accuracy. By embedding aerodynamic equations, the model maintains physical consistency while enhancing interpretability. Extensive experiments validate the effectiveness of our model for rapid aircraft aerodynamic parameter prediction, achieving a significant reduction in prediction error that improves performance by 29.25% in RMSE and 37.99% in MRE compared to existing methods. A 6.12% error increase on the test set confirms the model’s robust generalization ability. Full article

(This article belongs to the Special Issue Aerodynamics, Flight Dynamics and Control of Advanced Air Mobility Vehicles)

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16 pages, 4097 KiB

Open AccessArticle

Study on Plasma-Chemical Mode of Pulsed Coaxial Dielectric Barrier Discharge Plasma Based on Mass Spectrometry

by Diankai Wang, Yongzan Zheng, Baosheng Du, Jianhui Han, Ming Wen and Tengfei Zhang

Aerospace 2025, 12(5), 433; https://doi.org/10.3390/aerospace12050433 - 13 May 2025

Viewed by 248

Abstract

This study systematically investigates the dynamic evolution of chemical regimes in pulsed coaxial dielectric barrier discharge (DBD) plasma under atmospheric pressure using mass spectrometry. An innovative real-time mass spectrometric monitoring methodology was established, enabling the dynamic tracking of the formation and consumption processes [...] Read more.

This study systematically investigates the dynamic evolution of chemical regimes in pulsed coaxial dielectric barrier discharge (DBD) plasma under atmospheric pressure using mass spectrometry. An innovative real-time mass spectrometric monitoring methodology was established, enabling the dynamic tracking of the formation and consumption processes of key reactive species such as ozone (O₃) and nitrogen oxides (NO_x). Energy density was the critical parameter governing the evolution of gaseous chemical components, with a quantitative elucidation of the regulatory mechanisms of air flow rate and control voltage on plasma chemical regime transition kinetics. Experimental results revealed significant parametric correlations: Under a constant control voltage of 140 V, increasing the gas flow rate from 0.5 to 5.5 L/min prolonged the transition duration from O₃-NO_x coexistence regime to a NO_x-dominant regime from 408 s to 1210 s. Conversely, at a fixed flow rate of 3.5 L/min, elevating the control voltage from 120 V to 140 V accelerated this transition, reducing the required time from 2367 s to 718 s. Parametric sensitivity analysis demonstrated that control voltage exerts approximately 3.3 times greater influence on transition kinetics than flow rate variation. Through comprehensive analysis of the formation and consumption mechanisms of N, O, O₃, and NO_x species, we established a complete plasma chemical reaction network. This scheme provides fundamental insights into reaction pathways while offering practical optimization strategies for DBD systems. For aerospace applications, this work holds particular significance by demonstrating that the identified control parameters can be directly applied to plasma-assisted treatment of propellant wastewater at launch sites, where the efficient removal of nitrogen-containing pollutants is crucial. These findings advance both the fundamental understanding of atmospheric-pressure plasma chemistry and the engineering applications of plasma-based environmental remediation technologies in aerospace operations. Full article

(This article belongs to the Section Astronautics & Space Science)

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21 pages, 2865 KiB

Open AccessPerspective

Toward Sustainable Mars Exploration: A Perspective on Collaborative Intelligent Systems

by Thomas Janssen, Ritesh Kumar Singh, Phil Reiter, Anuj Justus Rajappa, Priyesh Pappinisseri Puluckul, Mohmmadsadegh Mokhtari, Mohammad Hasan Rahmani, Erik Mannens, Jeroen Famaey and Maarten Weyn

Aerospace 2025, 12(5), 432; https://doi.org/10.3390/aerospace12050432 - 13 May 2025

Viewed by 465

Abstract

Mars has long captivated the human imagination as a potential destination for settlement and scientific exploration. After deploying individual rovers, the next step in our journey to Mars is the autonomous exploration of the Red Planet using a collaborative swarm of rovers, drones, [...] Read more.

Mars has long captivated the human imagination as a potential destination for settlement and scientific exploration. After deploying individual rovers, the next step in our journey to Mars is the autonomous exploration of the Red Planet using a collaborative swarm of rovers, drones, and satellites. This concept paper envisions a sustainable Mars exploration scenario featuring energy-aware, collaborative, and autonomous vehicles, including rovers, drones, and satellites, operating around Mars. The proposed framework is designed to address key challenges in energy management, edge intelligence, communication, sensing, resource-aware task scheduling, and radiation hardening. This work not only identifies these critical areas of research but also proposes novel technological solutions drawn from terrestrial advancements to extend their application to extraterrestrial exploration. Full article

(This article belongs to the Special Issue Space Robotics and Embodied Intelligence: Advancing Autonomous Exploration)

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21 pages, 2937 KiB

Open AccessArticle

SatGuard: Satellite Networks Penetration Testing and Vulnerability Risk Assessment Methods

by Jin Xiao, Buhong Wang, Ruochen Dong, Zhengyang Zhao and Bofu Zhao

Aerospace 2025, 12(5), 431; https://doi.org/10.3390/aerospace12050431 - 12 May 2025

Viewed by 485

Abstract

Satellite networks face escalating cybersecurity threats from evolving attack vectors and systemic complexities. This paper proposes SatGuard, a novel framework integrating a three-dimensional penetration testing methodology and a nonlinear risk assessment mechanism tailored for satellite security. To address limitations of conventional tools in [...] Read more.

Satellite networks face escalating cybersecurity threats from evolving attack vectors and systemic complexities. This paper proposes SatGuard, a novel framework integrating a three-dimensional penetration testing methodology and a nonlinear risk assessment mechanism tailored for satellite security. To address limitations of conventional tools in handling satellite-specific vulnerabilities, SatGuard employs large language models (LLMs) like GPT-4 and DeepSeek-R1. By leveraging their contextual reasoning and code-generation abilities, SatGuard enables semi-automated vulnerability analysis and exploitation. Validated in a simulated ground station environment, the framework achieved a 73.3% success rate (22/30 attempts) across critical ports, with an average of 5.5 human interactions per test. By bridging AI-driven automation with satellite-specific risk modeling, SatGuard advances cybersecurity for next-generation space infrastructure through scalable, ethically aligned solutions. Full article

(This article belongs to the Section Astronautics & Space Science)

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58 pages, 3865 KiB

Open AccessReview

Flow and Flame Mechanisms for Swirl-Stabilized Combustors

by Paul Palies

Aerospace 2025, 12(5), 430; https://doi.org/10.3390/aerospace12050430 - 12 May 2025

Viewed by 590

Abstract

This article reviews the physical and chemical mechanisms associated with unsteady swirl-stabilized partially or fully lean premixed combustion. The processes of flame stabilization, mode conversion, swirl number oscillation, equivalence ratio oscillation, and vortex rollup are described. The key challenges associated with flow-flame dynamics [...] Read more.

This article reviews the physical and chemical mechanisms associated with unsteady swirl-stabilized partially or fully lean premixed combustion. The processes of flame stabilization, mode conversion, swirl number oscillation, equivalence ratio oscillation, and vortex rollup are described. The key challenges associated with flow-flame dynamics for several sources of perturbations are presented and discussed. The Rayleigh criterion is discussed. This article summarizes the scientific knowledge gained on swirling flames dynamics in terms of modeling, theoretical analysis, and transient measurements with advanced diagnostics. The following are specifically documented: (i) the effect of the swirler on swirling flames; (ii) the analytical results, computational modeling, and experimental measurements of swirling flame dynamics; (iii) the influence of flow features on flame response of swirling flames for combustion instabilities studies; and (iv) the identification and description of the combustion dynamics mechanisms responsible for swirl-stabilized combustion instabilities. Relevant elements from the literature in this context for hydrogen fuel are included. Full article

(This article belongs to the Special Issue Scientific and Technological Advances in Hydrogen Combustion Aircraft)

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17 pages, 13331 KiB

Open AccessArticle

The Three-Dimensional Transient Simulation of Cross-Shaped Grains in Hybrid Rocket Motors

by Xiangyu Meng, Huihuang Huang, Yifei Chen, Mingsen Yao, Jianyuan Wang and Hui Tian

Aerospace 2025, 12(5), 429; https://doi.org/10.3390/aerospace12050429 - 12 May 2025

Viewed by 270

Abstract

The process of spacecraft entry, deceleration, landing, and ascent requires high specific impulse, high reliability, and high-precision thrust adjustments for the power system. The new hybrid rocket motor adopts a complex-shaped grain and high-energy propellant, offering high-energy characteristics, continuously adjustable thrust, a relatively [...] Read more.

The process of spacecraft entry, deceleration, landing, and ascent requires high specific impulse, high reliability, and high-precision thrust adjustments for the power system. The new hybrid rocket motor adopts a complex-shaped grain and high-energy propellant, offering high-energy characteristics, continuously adjustable thrust, a relatively simple oxidant delivery system, and high reliability, making it an ideal power choice for the above systems. However, due to changes in the characteristic structure of the three-dimensional complex flame surface degradation process, it is difficult to accurately predict the motor performance. In this study, changes in the flow field structure and performance parameters during the operation of the cross-shaped grain hybrid rocket motor are presented using fuel surface reconstruction technology based on a dynamic mesh. The spatial distribution of the fuel surface is analyzed, and the accuracy of the model is verified via firing tests. The results show that the deviations of combustion chamber pressure and thrust are less than 0.6% and 1.7%, respectively. After the test, the deviation between the simulated port area and the CT-scanned port area is less than 3.5%. The accuracy of this model is verified in terms of the above two aspects, establishing a solid foundation for predicting the performance of future hybrid rocket motors with more complex-shaped grains. Full article

(This article belongs to the Section Astronautics & Space Science)

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40 pages, 2224 KiB

Open AccessArticle

Pursuit-Interception Strategy in Differential Games Based on Q-Learning-Cover Algorithm

by Yu Bai, Di Zhou and Zhen He

Aerospace 2025, 12(5), 428; https://doi.org/10.3390/aerospace12050428 - 12 May 2025

Viewed by 240

Abstract

Due to the limited difference in maneuverability between the pursuer and the evader in three-dimensional space, it is difficult for a single pursuer to capture the evader. To address this, this paper proposes a strategy where three pursuers intercept one evader and introduces [...] Read more.

Due to the limited difference in maneuverability between the pursuer and the evader in three-dimensional space, it is difficult for a single pursuer to capture the evader. To address this, this paper proposes a strategy where three pursuers intercept one evader and introduces a Q-learning-cover algorithm. Based on the motion models of the pursuers and the evader in three-dimensional space, this paper presents a region coverage scheme based on the Ahlswede ball and analyzes the convergence upper bound of the Q-learning-cover algorithm by designing an appropriate Lyapunov function. Through extensive model training, the successful capture of the evader by the pursuers in a three-on-one scenario was achieved. Finally, numerical simulation experiments and hardware-in-the-loop simulation experiments are presented, both of which demonstrate that the proposed Q-learning-cover algorithm can effectively realize the three-on-one encirclement and interception of the evading target. Full article

(This article belongs to the Section Aeronautics)

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13 pages, 2363 KiB

Open AccessArticle

Spectroscopic Quantification of Metallic Element Concentrations in Liquid-Propellant Rocket Exhaust Plumes

by Siyang Tan, Song Yan, Xiang Li, Tong Su, Qingchun Lei and Wei Fan

Aerospace 2025, 12(5), 427; https://doi.org/10.3390/aerospace12050427 - 11 May 2025

Viewed by 313

Abstract

Accurate quantification of metallic contaminants in rocket exhaust plumes serves as a critical diagnostic indicator for engine wear monitoring. This paper develops a hybrid method combining atomic emission spectroscopy (AES) theory with a genetic algorithm (GA) optimized backpropagation (BP) network to quantify the [...] Read more.

Accurate quantification of metallic contaminants in rocket exhaust plumes serves as a critical diagnostic indicator for engine wear monitoring. This paper develops a hybrid method combining atomic emission spectroscopy (AES) theory with a genetic algorithm (GA) optimized backpropagation (BP) network to quantify the metallic element concentrations in liquid-propellant rocket exhaust plumes. The proposed method establishes linearized intensity–concentration mapping through the introduction of a photon transmission factor, which is derived from radiative transfer theory and experimentally calibrated via AES measurement. This critical innovation decouples the inherent nonlinearities arising from self-absorption artifacts. Through the use of the transmission factor, the training dataset for the BP network is systematically constructed by performing spectral simulations of atomic emissions. Finally, the trained network is employed to predict the concentration of metallic elements from the measured atomic emission spectra. These spectra are generated by introducing a solution containing metallic elements into a CH₄-air premixed jet flame. The predictive accuracy of the method is rigorously evaluated through 32 independent experimental trials. Results show that the quantification error of metallic elements remains within 6%, and the method exhibits robust performance under conditions of spectral self-absorption, demonstrating its reliability for rocket engine health monitoring applications. Full article

(This article belongs to the Section Astronautics & Space Science)

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24 pages, 1678 KiB

Open AccessArticle

An Adaptation of Nonlinear Aerodynamic Models for Non-Traditional Control Effectors

by Christian R. Bolander and Douglas F. Hunsaker

Aerospace 2025, 12(5), 426; https://doi.org/10.3390/aerospace12050426 - 10 May 2025

Viewed by 234

Abstract

This paper presents the development of a novel aerodynamic model tailored for the Bio-Inspired Rotating Empennage (BIRE), a non-traditional fixed-wing aircraft empennage inspired by avian flight. The BIRE replaces the conventional vertical stabilizer with an extra degree of freedom for the horizontal stabilizer, [...] Read more.

This paper presents the development of a novel aerodynamic model tailored for the Bio-Inspired Rotating Empennage (BIRE), a non-traditional fixed-wing aircraft empennage inspired by avian flight. The BIRE replaces the conventional vertical stabilizer with an extra degree of freedom for the horizontal stabilizer, which is allowed to rotate about the body-fixed x axis. This empennage is similar to the tail of a bird, and allows control of both longitudinal and lateral moments. However, such a design introduces complex nonlinear longitudinal and lateral aerodynamic interactions, not typically accounted for in most fixed-wing aircraft aerodynamic models below stall. This work presents a nonlinear sinusoidal aerodynamic model that can be used for fixed-wing aircraft with this type of empennage. Although the aerodynamic model is constructed to accurately capture the degrees of freedom of this particular empennage design, similar methods could be used to develop other aerodynamic models for non-traditional control effectors. A large dataset of low-fidelity aerodynamic data was generated using a modern numerical lifting-line algorithm, and these data were fit to the nonlinear sinusoidal aerodynamic model. A method for fitting the data is demonstrated, and the results show that the nonlinear sinusoidal aerodynamic model can be fit to the data with an accuracy of less than 10% of the maximum deviation of the aerodynamic coefficients in root-mean-square error. The underlying physics of many of the longitudinal and lateral nonlinear sinusoidal aerodynamic properties of the aircraft are discussed in detail. The methodology presented here can be extended to other non-traditional control effectors, encouraging innovative approaches in aerodynamic modeling and aircraft design. In contrast, choosing to model control effectors using the traditional, linear approach can obscure key aerodynamic behaviors key for trim and control analyses. The study’s findings underscore the importance of developing adaptable aerodynamic models to support the advancement of next-generation aircraft designs and control systems. Full article

(This article belongs to the Section Aeronautics)

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30 pages, 4618 KiB

Open AccessArticle

Relative Pose Estimation of an Uncooperative Target with Camera Marker Detection

by Batu Candan and Simone Servadio

Aerospace 2025, 12(5), 425; https://doi.org/10.3390/aerospace12050425 - 10 May 2025

Viewed by 347

Abstract

Accurate and robust relative pose estimation is the first step in ensuring the success of an active debris removal mission. This paper introduces a novel method to detect structural markers on the European Space Agency’s Environmental Satellite (ENVISAT) for safe de-orbiting using image [...] Read more.

Accurate and robust relative pose estimation is the first step in ensuring the success of an active debris removal mission. This paper introduces a novel method to detect structural markers on the European Space Agency’s Environmental Satellite (ENVISAT) for safe de-orbiting using image processing and Convolutional Neural Networks (CNNs). Advanced image preprocessing techniques, including noise addition and blurring, are employed to improve marker detection accuracy and robustness from a chaser spacecraft. Additionally, we address the challenges posed by eclipse periods, during which the satellite’s corners are not visible, preventing measurement updates in the Unscented Kalman Filter (UKF). To maintain estimation quality in these periods of data loss, we propose a covariance-inflating approach in which the process noise covariance matrix is adjusted, reflecting the increased uncertainty in state predictions during the eclipse. This adaptation ensures more accurate state estimation and system stability in the absence of measurements. The initial results show promising potential for autonomous removal of space debris, supporting proactive strategies for space sustainability. The effectiveness of our approach suggests that our estimation method, combined with robust noise adaptation, could significantly enhance the safety and efficiency of debris removal operations by implementing more resilient and autonomous systems in actual space missions. Full article

(This article belongs to the Special Issue New Concepts in Spacecraft Guidance Navigation and Control)

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22 pages, 4144 KiB

Open AccessArticle

Wide-Range Variable Cycle Engine Control Based on Deep Reinforcement Learning

by Yaoyao Ding, Fengming Wang, Yuanwei Mu and Hongfei Sun

Aerospace 2025, 12(5), 424; https://doi.org/10.3390/aerospace12050424 - 10 May 2025

Viewed by 243

Abstract

In this paper, a controller design method based on deep reinforcement learning is proposed for a wide-range variable cycle engine with a turbine interstage mixed architecture. The PID controller is subject to limitations, including single-input single-output limitations, low regulation efficiency, and poor adaptability [...] Read more.

In this paper, a controller design method based on deep reinforcement learning is proposed for a wide-range variable cycle engine with a turbine interstage mixed architecture. The PID controller is subject to limitations, including single-input single-output limitations, low regulation efficiency, and poor adaptability when confronted with contemporary variable cycle engines that exhibit complex and multi-variable operating conditions. To solve this problem, this paper adopts a deep reinforcement learning method based on a deep deterministic policy gradient algorithm, and it applies an action space pruning technique to optimize the controller, which significantly improves the convergence speed of network training. In order to verify the control performance, two typical flight conditions are selected for simulation experiments as follows: in the first scenario, H = 0 km and Ma = 0, while in the second scenario, H = 10 km and Ma = 0.9. A comparison of the simulation results shows that the proposed deep reinforcement learning controller effectively addresses the engine’s multi-variable coupling control problem. In addition, it reduces response time by an average of 44.5%, while maintaining a similar overshoot level to that of the PID controller. Full article

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22 pages, 14643 KiB

Open AccessArticle

A Method for the Life Assessment of Aero-Engine Turbine Disks Based on a Time-Varying Load Spectrum

by Shunyu Yao, Xuming Niu, Zhigang Sun and Yingdong Song

Aerospace 2025, 12(5), 423; https://doi.org/10.3390/aerospace12050423 - 9 May 2025

Viewed by 348

Abstract

The load spectrum serves as the foundation for the life analysis of aero-engine turbine disks. To enhance the accuracy of life assessments for turbine disks, this study compiles a time-varying load spectrum for turbine disks. Firstly, a surrogate model for transient processes at [...] Read more.

The load spectrum serves as the foundation for the life analysis of aero-engine turbine disks. To enhance the accuracy of life assessments for turbine disks, this study compiles a time-varying load spectrum for turbine disks. Firstly, a surrogate model for transient processes at the critical points of turbine disks is established, enabling the rapid evaluation of the transient temperature and thermal stress at these points under complex loading histories. Secondly, a performance degradation model is established based on real engine test data, explicitly describing the general trend of performance degradation characteristics with respect to the cycle number and engine power. Finally, a time-varying load spectrum for turbine disks is compiled, considering both short-term transient processes and long-term performance degradation. The life of turbine disks at the fir-tree slot root and disk bore is assessed using the Manson–Coffin equation, Wilshire equation, and linear damage accumulation rule. The results indicate that neglecting transient processes leads to conservative life assessment results while neglecting performance degradation leads to dangerous life assessment results. Compared with traditional methods, the time-varying load spectrum significantly improves the accuracy and scientific nature of turbine disk life assessment. Full article

(This article belongs to the Section Aeronautics)

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20 pages, 4137 KiB

Open AccessArticle

GPU-Accelerated Eclipse-Aware Routing for SpaceWire-Based OBC in Low-Earth-Orbit Satellite Networks

by Hyeonwoo Kim, Heoncheol Lee and Myonghun Han

Aerospace 2025, 12(5), 422; https://doi.org/10.3390/aerospace12050422 - 9 May 2025

Viewed by 318

Abstract

Low-Earth-Orbit (LEO) satellite networks offer a promising avenue for achieving global connectivity, despite certain technical and economic challenges such as high implementation costs and the complexity of network management. Nonetheless, real-time routing remains challenging because of rapid topology changes and strict energy constraints. [...] Read more.

Low-Earth-Orbit (LEO) satellite networks offer a promising avenue for achieving global connectivity, despite certain technical and economic challenges such as high implementation costs and the complexity of network management. Nonetheless, real-time routing remains challenging because of rapid topology changes and strict energy constraints. This paper proposes a GPU-accelerated Eclipse-Aware Routing (EAR) method that simultaneously minimizes hop count and balances energy consumption for real-time routing on an onboard computer (OBC). The approach first employs a Breadth-First Search (BFS)–based K-Shortest Paths (KSP) algorithm to generate candidate routes and then evaluates battery usage to select the most efficient path. In large-scale networks, the computational load of the KSP search increases substantially. Therefore, CUDA-based parallel processing was integrated to enhance performance, resulting in a speedup of approximately 3.081 times over the conventional CPU-based method. The practical applicability of the proposed method is further validated by successfully updating routing tables in a SpaceWire network. Full article

(This article belongs to the Section Astronautics & Space Science)

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21 pages, 16482 KiB

Open AccessArticle

Evaluation of Aerodynamic and Sonic Boom Performance of Supersonic Transport Aircrafts with Multiple Wing Configurations

by Wataru Yamazaki and Shu Ishida

Aerospace 2025, 12(5), 421; https://doi.org/10.3390/aerospace12050421 - 9 May 2025

Viewed by 230

Abstract

In this study, two-dimensional airfoil shapes obtained in aerodynamic optimizations are converted to three-dimensional wing models and then their aerodynamic and sonic boom performance are evaluated. The airfoil shapes analyzed are the diamond, Busemann, new supersonic biplane (NSB), and triplane airfoil configurations. The [...] Read more.

In this study, two-dimensional airfoil shapes obtained in aerodynamic optimizations are converted to three-dimensional wing models and then their aerodynamic and sonic boom performance are evaluated. The airfoil shapes analyzed are the diamond, Busemann, new supersonic biplane (NSB), and triplane airfoil configurations. The NSB is a modified version of the Busemann biplane airfoil proposed in previous studies. The triplane airfoil configuration is obtained in this study by maximizing the lift-to-drag ratio using an aerodynamic topology optimization method. Based on the obtained two-dimensional airfoil shapes, three-dimensional multiple (biplane/triplane) wing configurations are designed. The aerodynamic and sonic boom performance of these configurations is evaluated in detail through three-dimensional flow analyses as well as acoustic propagation analyses. The aerodynamic superiority of the multiple wing configurations is confirmed in this study. Full article

(This article belongs to the Special Issue Research and Development of Supersonic Aircraft)

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Aerospace, Volume 12, Issue 5 (May 2025) – 90 articles

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