Aerospace Science and Technology最新文献

{"title":"Design and aerodynamic stability improvement study of a non-axisymmetric stator fan in a distorted insertion plate configuration","authors":"","doi":"10.1016/j.ast.2024.109537","DOIUrl":"10.1016/j.ast.2024.109537","url":null,"abstract":"<div><p>The design of anti-distortion fans must ensure the reliable operation and flight safety of propulsion systems under inlet distortion conditions. This research uses an insertion plate to obtain the inlet distortion flow field for a specific type of turbofan engine. Based on the characteristics of distortion effects, a novel strategy is proposed to rapidly implement a non-axisymmetric stator (NAS) quasi-three-dimensional design to create anti-distortion fan designs and improve the performance and stability of the fan in distortion environments. Numerical studies show that under three rotational speed operating conditions, the NAS effectively improves the total pressure ratio and efficiency characteristics of the fan under inlet distortion conditions. Compared to the prototype, the NAS can significantly increase the stability margins by 10.31 %, 8.31 %, and 7.39 % under the three different speed operating conditions, which effectively expands the stability boundaries. The NAS design directly affects the distortion region, effectively improves the incidence angle of stator vanes in the distortion region, suppresses the development and migration of vortices inside the stator passage, and significantly reduces the stator vane diffusion factor. Because it effectively eliminates corner separations and makes the incidence angle distribution of stator vanes relatively circumferentially uniform, the internal flow field of the fan's stator vanes and overall aerodynamic performance of the fan improve. Furthermore, the NAS design can improve the internal flow field downstream of the fan, direct the nonuniform flow field at the inner bypass outlet toward circumferential uniformity, and effectively improve flow field uniformity.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144113","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":"Event-triggered lifted robust MPC stabilization control for space telescope on dual-rate actuated rigid spacecraft systems","authors":"","doi":"10.1016/j.ast.2024.109553","DOIUrl":"10.1016/j.ast.2024.109553","url":null,"abstract":"<div><p>This study addresses the pose stabilization control problem for enhancing a space telescope mounted on a spacecraft system under a dual-rate actuated setup. An input-lifting approach is utilized to manage the dual rates in the control components, specifically the orbital space telescope and its loading platform. To counteract external spatial perturbations and spacecraft system uncertainties, an integrated control scheme is proposed, combining real-time model parameter estimation, active compensation control, and event-triggered lifted robust model predictive control (ET-LRMPC). The event-triggered mechanism in the proposed algorithm minimizes computational resource consumption while maintaining effective spacecraft control. Numerical simulations demonstrate that the proposed control scheme achieves favorable results under persistent external perturbations and model uncertainties. In terms of the overshoot, the algorithm proposed reduces the control effect by up to 87.1% in the spatial displacement of the payload and 98.6% in the Euler attitude angle compared to the conventional control algorithm. For the control of the base, the amount of overshoots with respect to the conventional control in spatial displacement and Euler attitude angle is reduced by 49% and 97.1%.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143985","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":"Adaptive pseudospectral successive convex optimization for six-degree-of-freedom powered descent guidance","authors":"","doi":"10.1016/j.ast.2024.109544","DOIUrl":"10.1016/j.ast.2024.109544","url":null,"abstract":"<div><p>Guidance for six-degrees-of-freedom powered descent is more challenging due to its stronger nonlinearity compared to three-degrees-of-freedom. The standard convex programming algorithm has been difficult to effectively address this problem. To enhance the performance of successive convex programming in terms of both optimality and accuracy, an adaptive pseudospectral successive convex optimization algorithm is proposed in this paper. First, it transforms the nonlinear optimal control problem into a convex subproblem by integrating global pseudospectral discretization with local linearization. Second, a parameter-adaptive successive convexification algorithm is proposed, which adaptively adjusts the trust region size based on the update rate of the optimal trajectory. Last, the global error and local error are accurately calculated based on the pseudospectral method. To tackle the issue of excessively large local errors caused by nonlinearity, an adaptive grid method is proposed to refine the mesh grid. Simulation results demonstrate the efficacy of the proposed pseudospectral convex optimization method and adaptive mesh grid method in reducing local errors and improving solution accuracy. Furthermore, the proposed parameter-adaptive successive convex optimization algorithm exhibits adaptability and optimality across different initial conditions, while also improving solution accuracy.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143986","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":"Configuration optimization of PV array for stratospheric airship under nonuniform radiation condition","authors":"","doi":"10.1016/j.ast.2024.109550","DOIUrl":"10.1016/j.ast.2024.109550","url":null,"abstract":"<div><p>The nonuniform solar irradiation on the stratospheric airship surface leads to overlooked mismatch losses in photovoltaic (PV) array. Proper configuration for PV array is crucial but frequently neglected in airship energy system research. In this paper, a mathematical model coupled with the layout of PV array on airship surface, radiation model, electrical model and energy balance model is established. The deployment of PV pack based on the distribution characteristics of solar radiation on airships surface is analyzed. Three maximum power point tracking configurations for the PV array are investigated in detail. The results indicate that mounting PV pack in axial series on stratospheric airships leads to higher power output compared to parallel-connected deployment, PV packs on stratospheric airships exhibit significant output power differences along the circumferential direction and minor differences along the axial direction, the peak of daily maximum output difference ratio is merely 0.4 % between the PV array under the distributed maximum power point tracking (DMPPT) and the partial distributed global maximum point tracking (PDMPPT) configuration, and PDMPPT configuration needs much fewer module, it emerges as the optimal choice for stratospheric airship PV array. This investigation can provide references for the further PV array configuration optimization under nonuniform radiation condition.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144010","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":"Numerical investigation of aerodynamic characteristics in tandem cascades with various curving strategies","authors":"","doi":"10.1016/j.ast.2024.109548","DOIUrl":"10.1016/j.ast.2024.109548","url":null,"abstract":"<div><p>Tandem configurations with curved blades can improve the flow field in compressor cascades. This study conducts a numerical investigation into the impact of various curving strategies on the losses and flow structures within tandem cascades. Curving strategies of three distinct configurations (curving both blades, solely the rear blade, and solely the front blade) along with three curved angles (5°, 10°, and 15°) are compared. Four primary vortex structures are causing losses in the tandem cascades. Loss weight coefficients, derived from each vortex, are adopted to quantify the proportion of losses. All curving strategies mitigate the accumulation of low-energy fluid near the endwalls, weakening the passage vortex. Various curving strategies have different effects on losses of the endwall spanwise vortex and trailing edge shedding vortices. The influence of curved angles on the three configurations indicates that curving both blades at 5° and curving the front blade at 5° or 10° can mitigate losses. An increasing loss is observed when the rear blade curves at any angle alone. Curving both blades or only the front blade mitigates the corner separation while the curved rear blade exacerbates it. The novelty of this study lies in applying topology analysis to establish correlations between losses, vortices, and topological configurations. This approach is a pivotal research methodology for elucidating the underlying mechanisms of loss generation and vortex dynamics within curved tandem cascades.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144112","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 circular impact time guidance","authors":"","doi":"10.1016/j.ast.2024.109543","DOIUrl":"10.1016/j.ast.2024.109543","url":null,"abstract":"<div><p>To effectively control impact time and ensure terminal acceleration converges to zero under the look angle constraint, this paper proposes a generalized circular impact time guidance law, providing a deeper insight into circular guidance. The proposed guidance law is formulated based on a generalized circular guidance equation that offers an explicit solution for the time to go. The convergence of both miss-distance and terminal acceleration to zero is proven using Bernoulli number theory. Impact time control is achieved by employing a fixed-time convergent controller that guides the look angle to track desired values. Additionally, the look angle constraint is addressed by incorporating a well-designed function into the acceleration. The proposed guidance law does not require estimated time to go and small-angle assumptions for its implementation. By predicting the mean speed, the proposed guidance law remains valid for missiles with varying speeds. Furthermore, the planar results are extended to three-dimensional scenarios by adopting the concept of the engagement plane. Nonlinear simulations demonstrate the effectiveness, advantages, and robustness of the proposed guidance law in the presence of disturbances and autopilot lag.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150414","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":"Numerical design of a flow restrictor for tanked liquid nitrogen undergoing reduced-gravity flights","authors":"","doi":"10.1016/j.ast.2024.109539","DOIUrl":"10.1016/j.ast.2024.109539","url":null,"abstract":"<div><p>NASA and the United States are designing multiple reduced-gravity cryogenic payloads to study various two-phase flow phenomena that will be ground-tested and subsequently flight-tested onboard parabolic flights. The setup will undergo 25+ parabolas per flight, during which liquid nitrogen will be cyclically or continuously demanded from a supply Dewar. The minimum gravity level during a parabolic maneuver is 0 ± 0.05 g, which can last around 20 seconds, and the maximum expected gravity is 2 g, which lasts for 40-50 seconds. This Computational Fluid Dynamics (CFD) study focuses on the design and optimization of a bi-directional perforated plate and a ring baffle to help ensure single-phase liquid nitrogen outflow during all flight phases, regardless of supply tank liquid level or gravity level. CFD analyses carried out using ANSYS FLUENT indicate that a double perforated plate with an open area percent equal or less than 0.63% can achieve high values of expulsion efficiency. Structural analyses performed using the ANSYS Static Structural solver determined the minimum plate thickness needed to withstand gravitational and hydrodynamic forces experienced during the flight.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142128803","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 characteristics and vibration control of composite laminate wall panels in electric aircraft using NiTi shape memory alloys","authors":"","doi":"10.1016/j.ast.2024.109517","DOIUrl":"10.1016/j.ast.2024.109517","url":null,"abstract":"<div><p>This paper investigates the dynamic characteristics and vibration control of a new-energy electric aircraft cockpit wall panel. An innovative boundary-splitting Rayleigh-Ritz method is introduced for modal analyses of wall panel structures in thermal environments, verified with the hammering and finite element methods, showing a maximum error of 5.42 %. NiTi shape memory alloy (SMA) wires are embedded in composite structures for vibration control, with the first theoretical-experimental validation performed. A parametric fitting-computational model for NiTi-SMA is developed to extract mechanical parameters from hysteresis data. Theoretical models are decoupled into dynamical equations using the Galerkin truncation method. The damping capability of NiTi-SMA is demonstrated by solving the amplitude using the harmonic balance and Runge-Kutta methods. Room-temperature and variable-temperature vibration tests show over 30 % vibration control capability with optimized embedding methods. These experimental results confirm the theoretical findings, providing support for the analysis and vibration control of new-energy aircraft.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142150412","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":"Surrogate based design space exploration and exploitation for an efficient airfoil optimization under uncertainties using transition models","authors":"","doi":"10.1016/j.ast.2024.109532","DOIUrl":"10.1016/j.ast.2024.109532","url":null,"abstract":"<div><p>The pursuit of sustainable, zero-emission air travel is heavily dependent on the creation of energy-efficient aircraft. Key strategies for achieving this sustainability in aviation include reducing fuel consumption through low-drag designs harnessing laminar flow. However, designing aircraft with laminar flow characteristics is complex due to their sensitivity to environmental and operational factors. This study tackles the challenge of developing energy-efficient aircraft by using computational fluid dynamics models and sophisticated optimization techniques that account for uncertainty. Our approach demonstrates the effectiveness of surrogate-based optimization and uncertainty quantification in optimizing airfoil drag for a natural laminar airfoil (NLF) design. We use surrogate models, trained with data from detailed airfoil simulations, which include a boundary layer code coupled with a linear stability method and a newly developed transition transport model. Transition location predicted using transition models facilitate an accurate drag prediction used in the optimization process. The accuracy of these surrogate models is enhanced through active sampling strategies. Our robust optimization method considers uncertainties in environmental and operational conditions, offering a deeper insight into their effects on crucial design parameters. Unlike traditional deterministic aerodynamic design optimization, our findings highlight the efficacy and precision of uncertainty-based optimization in achieving robust NLF airfoil designs over large (exploration mode) and small (exploitation mode) design spaces. Investigating design space parameterization based on the size of design variables reveals significant differences in optimal airfoil configurations. The optimized designs we propose favor delayed transition, in contrast to deterministic designs which often result in significant loss of laminarity when facing uncertainties. This study represents a significant advancement in aerospace engineering, providing a practical and effective methodology for creating energy-efficient airfoil designs. The application of these advanced optimization and uncertainty quantification techniques shows great potential for the wider field of aerospace engineering, paving the way for more resilient and robust aircraft designs.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S127096382400662X/pdfft?md5=836c01bd1ef478d7085453006cca31d5&pid=1-s2.0-S127096382400662X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122465","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}

{"title":"Mechanical modeling and parameter analysis of the docking process for probe-drogue docking mechanisms","authors":"","doi":"10.1016/j.ast.2024.109536","DOIUrl":"10.1016/j.ast.2024.109536","url":null,"abstract":"<div><p>The on-orbit probe-drogue berthing docking of two spacecraft can effectively reduce impact force and adjust for initial deviations. However, its dynamic response and influence behaviors of design parameters are extremely concerning but difficult to obtain because of its complicated structure. In this paper, a fast mechanical modeling (FMM) method is proposed to obtain the dynamic response of probe-drogue docking mechanisms during spacecraft berthing missions. Regarding the quasi-static docking process, complex dynamic docking behaviors are simplified and decoupled. The FMM method divides docking into three contact processes based on the scene of contact; it analyzes the deviation adaptive docking principle of this type of docking mechanism by establishing the kinematics and mechanics models of active and passive parts. The finite element simulations and experiments of probe-drogue berthing docking were used to compare with the proposed FMM. The comparison results of different initial deviation conditions indicate that the FMM method guarantees computation accuracy and increases computation speed by two orders of magnitude, which greatly reduces computation costs. Then this efficient FMM method was utilized to analyze the influence of key parameters, such as friction coefficient and cone angle, on the contact force and driving force of the docking mechanism. The conclusions of the parameter analysis of probe-drogue berthing docking can be used to reduce contact force and accelerate iterative design as a reference for the design of this kind of docking mechanisms, making the docking process optimized and reliable.</p></div>","PeriodicalId":50955,"journal":{"name":"Aerospace Science and Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142147942","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}