{"title":"A proposed methodology for diverterless supersonic inlet aerodynamic integration with a generic forebody","authors":"John J. Vaca-Rios, Hernán D. Cerón-Muñoz","doi":"10.1016/j.ast.2025.110135","DOIUrl":"10.1016/j.ast.2025.110135","url":null,"abstract":"<div><div>The Diverterless Supersonic Inlet (DSI) is implemented for both supersonic flow compression and boundary layer diversion using a three-dimensional surface known as a bump, along with an appropriately designed cowl lip. In the present work, the bump surface was designed using the Stream Tracing Technique and integrated into a generic forebody. First, simulations with a bump on a flat plate were conducted to determine the design Mach number for the specific bump. The cowl lip was modeled using the bump's shock wave angle at its design Mach number. At this stage, the bump was integrated into a generic forebody.</div><div>All numerical solutions of the Reynolds-Averaged Navier-Stokes (RANS) equations were performed using ANSYS Fluent. The inlet's performance parameters, including total pressure recovery, flow distortion, and mass flow, were evaluated. Both subcritical and critical operating conditions were simulated. The critical operating condition was achieved after some adjustments to the back pressure. Performance investigation involving the angle of attack was conducted under the critical operating condition. For all angles of attack examined here, the pressure distributions along the bump centerline exhibited relatively consistent behavior. However, changes were more pronounced for positive angles of attack than for negative ones. The results showed that the bump surface can maintain operational shock structures even at high supersonic angles of attack.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110135"},"PeriodicalIF":5.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636793","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}
Zixu Wang, Pan Li, Zhenhua Zhu, Renliang Chen, Junbiao Shen
{"title":"Control allocation design for equal control sensitivity of tiltrotor aircraft","authors":"Zixu Wang, Pan Li, Zhenhua Zhu, Renliang Chen, Junbiao Shen","doi":"10.1016/j.ast.2025.110134","DOIUrl":"10.1016/j.ast.2025.110134","url":null,"abstract":"<div><div>Control redundancy is a considerable challenge in tiltrotor aircraft, making an effective control allocation scheme critical for ensuring safe and smooth transitional flights. This study focuses on medium-to-large tiltrotor aircraft with fly-by-wire flight control systems and introduces an equal control sensitivity (ECS) allocation method based on ganging control (GC). This method aims to quantify and standardize the control allocation design process and accommodate various complex optimization objectives, including minimizing the control surface deflection angle, yaw-to-roll control coupling, and transient control loads on the nacelle tilt axis and rotor hub. The results show that the ECS allocation method specifically mitigates control coupling effects and transient peak responses in the nacelle tilt-axis and rotor hub moments while maintaining equal control sensitivity within the conversion corridor. In addition, the ECS allocation method has a significant advantage in reducing the variation range and dispersion of gain scheduling in feedback loops as it enables a smooth transition from helicopter mode to airplane mode using fixed control gains, while demonstrating good disturbance rejection capabilities. The ECS allocation method simplifies the workload of the feedback loop control gain design.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110134"},"PeriodicalIF":5.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685459","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}
Huanhuan Hu, Pan Wang, Haoqi Chang, Rong Yang, Weizhu Yang, Lei Li
{"title":"A hybrid single-loop approach combining the target beta-hypersphere sampling and active learning Kriging for reliability-based design optimization","authors":"Huanhuan Hu, Pan Wang, Haoqi Chang, Rong Yang, Weizhu Yang, Lei Li","doi":"10.1016/j.ast.2025.110136","DOIUrl":"10.1016/j.ast.2025.110136","url":null,"abstract":"<div><div>In engineering design, system-level requirements typically provide each subsystem with specific target reliability indexes. This makes reliability-based design optimization (RBDO) under the prescribed target reliability index particularly relevant for practical applications. However, solving complex nonlinear RBDO problems often involves nested double-loop optimization, leading to prohibitive computational costs and potential convergence issues. To address these challenges, this study proposes a minimum performance measure-based hybrid single-loop approach (TSPM-AK-HSLA) that integrates target beta-hypersphere sampling and active learning Kriging. First, a novel sampling strategy combining target beta-hypersphere and local enhancement is introduced to accurately identify the minimum performance target point (MPTP) without requiring gradient calculations or iterative search direction adjustments. Second, an identification criterion for the active constraint is incorporated to determine whether the Kriging model needs updating within the local region around the approximate MPTP, thereby focusing sampling efforts for improved efficiency. Finally, an adaptive strategy is employed to implement the hybrid single-loop approach, accelerating convergence while maintaining robustness for nonlinear problems. Comparative analyses with existing methods, along with two numerical MPTP search examples and two nonlinear RBDO examples demonstrate the superior efficiency and accuracy of the proposed approach. The RBDO application for an engineering clamping mechanism of the aircraft engine guides the design.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110136"},"PeriodicalIF":5.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628747","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":"Dynamic modeling of liquid-filled free-floating space robot and joint trajectory planning with considering liquid positioning","authors":"Yu Lu, Baozeng Yue","doi":"10.1016/j.ast.2025.110133","DOIUrl":"10.1016/j.ast.2025.110133","url":null,"abstract":"<div><div>The free-floating space robot mainly consists of three parts: the main rigid body, the robotic arm and the liquid fuel, where the movements in component parts interact with each other and generate complex coupled dynamic problems. This article establishes an efficient coupled dynamic model of a liquid-filled space robot based on the alternative and iterative algorithm. The moving pulsating ball model (MPBM) is used to describe the dynamic behavior of liquid with large sloshing, while the robotic arm module is modeled using the Newton-Euler method for recursive dynamics. To validate the MPBM, the rigid body motion obtained from the coupled dynamics model is used as the input condition for the Computational Fluid Dynamics (CFD) method. The calculated liquid motion, sloshing force and torque have a high degree of agreement with the simulation results of the equivalent model, thereby verifying the effectiveness of the model proposed in this paper. Finally, based on cosine series basis and Particle Swarm Optimization (PSO) algorithm, the joint trajectory planning problem considering liquid positioning are studied. This method can minimize the deviation of liquid fuel location from the initial position without introducing additional control force and torque after the robotic arm completes the specified action, which is of important significance for liquid management and overall design and dynamics analysis for space robot system in microgravity environments.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110133"},"PeriodicalIF":5.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628748","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}
Bo Zhang, Xi Chen, Xiangnan Fan, Guangming Ren, Xiaohua Gan
{"title":"Dynamic characteristics of a rotor system supported by squeeze film dampers during maneuvering flight: Simulation and experiment","authors":"Bo Zhang, Xi Chen, Xiangnan Fan, Guangming Ren, Xiaohua Gan","doi":"10.1016/j.ast.2025.110119","DOIUrl":"10.1016/j.ast.2025.110119","url":null,"abstract":"<div><div>With the improvement of maneuverability, the excessive vibration issue of rotor systems in aircraft engines has become increasingly prominent. The dynamic characteristics of a rotor system supported by squeeze film dampers (SFDs) during maneuvering flights were investigated. A comprehensive 6-degree-of-freedom (DOF) finite element model for simulating a gas generator rotor was developed by finite element method (FEM), incorporating the effects of inertial forces induced by maneuvers on the rotor system. The Newmark method combined with Newton-Raphson iteration and an adaptive time-stepping strategy were developed to calculate the transient responses of rotor-SFD-support system. The rotor-SFD-support system was assembled on an innovative experimental platform that simulated different maneuvering flights by imposing base motions on the rotor system. To analyze the simulated and experimental transient responses, time-domain waveforms, Bode diagrams, spectrum cascades, and whirl orbits were illustrated in the cases of various base motions, including rolling, pitching, and yawing. The results revealed that the responses of rotor system are significantly influenced by the gravity and inertial forces induced by base motions. The simulation results were compared with the experimental data to verify the accuracy of the proposed 6-DOF finite element model and the corresponding simulation algorithm. Overall, it provides flexible and efficient modeling, simulation, and experimental methods for analyzing the dynamic characteristics of engine rotor systems during aircraft maneuvers, which is beneficial for the optimization design of aircraft engines.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110119"},"PeriodicalIF":5.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621364","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":"Generalized Newton/Jacobian-free/Krylov iteration-based successive convexification for rapid trajectory optimization","authors":"Cong Zhou , Yutong Hu , Sai Chen , Chaoyong Li","doi":"10.1016/j.ast.2025.110121","DOIUrl":"10.1016/j.ast.2025.110121","url":null,"abstract":"<div><div>This paper presents generalized Newton/Jacobian-free/Krylov iteration-based successive convexification approaches for rapid trajectory optimization. To this end, a generalized Newton iteration technique is introduced to successively convexify the nonlinear dynamics, reducing the optimization scale while retaining the same convergence rate. In addition, the Krylov subspace method is employed to replace the matrix inverse operation that otherwise rooted in each generalized Newton iteration. Compared with existing sequential convex programming strategies, the proposed scheme not only reduces the computation complexity, but also evaporates the need of analytically computing the Jacobian matrix, and hence is more suitable for online application. Numerical simulations are conducted to verify performance of the proposed methods.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110121"},"PeriodicalIF":5.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578505","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":"Effect of wing sweep and asymmetry on flight dynamics of a sweep-morphing aircraft","authors":"Peng Si , Mingjian Wu , Yongqing Huo , Zhilin Wu","doi":"10.1016/j.ast.2025.110120","DOIUrl":"10.1016/j.ast.2025.110120","url":null,"abstract":"<div><div>Wing asymmetry plays a critical role in the flight dynamics of tube-launched sweep-morphing aircraft, particularly during missions requiring dynamic shape adaptations. Although previous studies on sweep-morphing wings primarily assumed symmetric left-right configurations, this research highlights the significant effects of inherent asymmetries on flight stability. Results indicate that wing asymmetry reduces lift due to a diminished fuselage upwash effect, with asymmetric wings generating lower lift than symmetric configurations. In longitudinal dynamics, asymmetric wings reduce both static and dynamic stability, with the phugoid mode being particularly sensitive to wing asymmetry. Conversely, in lateral-directional dynamics, wing asymmetry improves the stability of roll subsidence, Dutch roll, and spiral modes compared to symmetric configurations. This study systematically analyzes the impact of wing asymmetry on both aerodynamic performance and flight dynamics of sweep-morphing aircraft, providing new insights into stability characteristics and control requirements. The findings offer crucial guidance for designing agile and adaptive unmanned aerial vehicles (UAVs) with morphing wings, emphasizing the necessity of considering wing asymmetry in flight control strategies.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110120"},"PeriodicalIF":5.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621365","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}
Ziqi Dai , Riul Jung , Michael J. Kingan , Digby Symons
{"title":"Iterative BEMT analysis extended to model coaxial rotor aerodynamic performance in hover","authors":"Ziqi Dai , Riul Jung , Michael J. Kingan , Digby Symons","doi":"10.1016/j.ast.2025.110122","DOIUrl":"10.1016/j.ast.2025.110122","url":null,"abstract":"<div><div>This paper addresses the aerodynamic modelling of coaxial contra-rotating unmanned aerial vehicle (UAV) rotor blades in hover using a novel adapted blade element momentum theory (BEMT) model. The investigation incorporates numerical, computational, and experimental methods. The traditional BEMT approach is extended to iteratively solve for the axial velocities of both upper and lower rotors, accounting for mutual rotor-to-rotor interaction, rotor axial separation distance, and tip loss effects. Wake contraction is evaluated using a prescribed wake model. Computational fluid dynamics (CFD) simulations were implemented to conduct two-dimensional (2D) axisymmetric studies to validate the wake contraction model. Results from the new coaxial BEMT model were then compared to three-dimensional (3D) CFD results for a rotor pair. The BEMT predictions show strong alignment with CFD, accurately capturing both the wake contraction radius and the radial distributions of aerodynamic loads. The developed BEMT coaxial model was also validated against literature data published for different blade designs, showing strong agreement. Additionally, the BEMT results were compared with experimental measurements across various rotational speeds and showed good agreement. The study indicates that the developed coaxial BEMT model is effective in capturing the trends and magnitude of the performance of coaxial contra-rotating rotor blades at much lower set-up and computational costs than higher fidelity CFD calculations.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110122"},"PeriodicalIF":5.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xing Lv , Jiangong Zhao , Chenzhuo Hao , Zhan Wen , Peijin Liu , Wen Ao
{"title":"Molecular dynamics simulation of aluminum combustion in an oxygen environment under electric field","authors":"Xing Lv , Jiangong Zhao , Chenzhuo Hao , Zhan Wen , Peijin Liu , Wen Ao","doi":"10.1016/j.ast.2025.110123","DOIUrl":"10.1016/j.ast.2025.110123","url":null,"abstract":"<div><div>This study, for the first time, investigates the combustion behavior of aluminum(Al) in an oxygen environment under various electric fields using molecular dynamics simulations. The results indicate that the electric field enhances the mobility of Al atoms and reduces the activation energy, leading to a particle acceleration effect that boosts the burning rate and shortens the reaction time. As the electric field strength increases, the O/Al ratio of the final products approaches the theoretical value of 1.5 for complete combustion, and the number of intermediate species increases, indicating more thorough and intense Al combustion. Specifically, the electric field induces the generation of more free radicals during the reaction and reduces the average distance between Al and O atoms, thereby increasing atomic collision rates and contact frequency, further facilitating Al combustion. Under a strong electric field of 0.01V/Å, the electric field disrupts the original force equilibrium of Al atoms, leading to Al atoms escape and the gradual fragmentation of Al particles. Experimental studies on the electric field regulation of single Al particle combustion reveal that the reaction time is reduced by approximately 40 % under an electric field. Additionally, the combustion flame becomes larger and brighter, verifying that the electric field promotes the combustion of single Al particles. Under a high-voltage electric field of 5 kV, fragmentation of Al is observed during the combustion process. These experimental findings corroborate the molecular dynamics simulations, providing valuable insights for understanding and controlling Al combustion behavior under electric field.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110123"},"PeriodicalIF":5.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593791","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}
Shouzuo Li , Xiangyu Wang , Qiankun He , Songtao Wang , Le Cai
{"title":"Aerothermal performance of different relative positions of holes and ribs of a flat-plate film cooling hole with a straight-ribbed crossflow coolant channel","authors":"Shouzuo Li , Xiangyu Wang , Qiankun He , Songtao Wang , Le Cai","doi":"10.1016/j.ast.2025.110114","DOIUrl":"10.1016/j.ast.2025.110114","url":null,"abstract":"<div><div>The integration of internally ribbed cooling channels with external film cooling is a widely adopted cooling technique for gas turbines. This study numerically investigated the effects of different relative positions of holes/ribs on the flow and heat transfer characteristics of cylindrical film-cooling holes. Nine film-cooling hole position cases, two crossflow Reynolds numbers (<em>Re</em> = 200,000−600,000), and four blowing ratios (M = 0.5 − 2.0) were considered. All cases used the ribbed crossflow supply method with a rib height of 0.4 D. We analyzed the change rule in the cooling performance and discharge coefficients with the relative positions of holes/ribs. In addition, we analyzed the mechanism contributing to relevant changes from the perspectives of the structure of the flow field inside and outside the holes, as well as the aerodynamic and heat transfer characteristics. The relative positions of the holes/ribs exerted a more pronounced impact at high crossflow Reynolds numbers. Across the entire range of operating conditions, positions 6 and 9 demonstrated the highest film-cooling performance and discharge coefficient, respectively. When the crossflow Reynolds number was relatively high and the blowing ratio was 1.0, the difference in the film-cooling efficiency between positions 6 and 8 was 45.9 %, which increased to 88.1 % at a blowing ratio of 2.0. Hence, the relative positions of film-cooling holes affect the degree to which the holes are affected by the crossflow, which consequently affects the flow-field structure and aerothermal properties. This research aids in achieving refinement and integration in the design of turbine blade cooling structures.</div></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":"161 ","pages":"Article 110114"},"PeriodicalIF":5.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548341","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}