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Model for Asymmetry of Shock/Boundary Layer Interactions in Nozzle Flows 认领 引用 被引量：4
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作者 Wang Chengpeng Zhuo Changfei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第1期146-153,共8页
The reason for the asymmetry phenomenon of shock/boundary layer interactions(SBLI)in a completely symmetric nozzle with symmetric flow conditions is still an open question.A model for the asymmetry of nozzle flows was... The reason for the asymmetry phenomenon of shock/boundary layer interactions(SBLI)in a completely symmetric nozzle with symmetric flow conditions is still an open question.A model for the asymmetry of nozzle flows was proposed based on the properties of fluid entrainment in the mixing layer and momentum conservation.The asymmetry model is deduced based on the nozzle flow with restricted shock separation,and is still applicable for free shock separation.Flow deflection angle at nozzle exit is deduced from this model.Steady numerical simulations are conducted to model the asymmetry of the SBLIs in a planar convergent-divergent nozzle tested by previous researchers.The obtained values of deflection angle based on the numerical results of forced symmetric nozzle flows can judge the asymmetry of flows in a nozzle at some operations.It shows that the entrainment of shear layer on the separation induced by SBLTs is one of the reasons for the asymmetry in the confined SBLIs. 展开更多
关键词 asymmetry shock/boundary layer interactions nozzle flow entrainment
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Numerical Simulation of Two-Dimensional Shock/Boundary-Layer Interaction between a Rocket and Booster 认领 引用 被引量：1
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作者 孙为民 夏南 谭发生 《Advances in Manufacturing》 EI CAS 2000年第S1期25-28,共4页
A two-dimensional Reynolds-averaged Navier-Stokes solver is applied to analyze the aerodynamic behavior of the Shock/Boundary-Layer interaction of rocket with a boosted The K-ε turbulence model and a finite volume me... A two-dimensional Reynolds-averaged Navier-Stokes solver is applied to analyze the aerodynamic behavior of the Shock/Boundary-Layer interaction of rocket with a boosted The K-ε turbulence model and a finite volume method in a unstructured body-fitted curvilinear coordinates have been used. The results indicate that the separation and the reattachment occur in the Boundary-Layer of the main rocket because of the shock interaction. The shape of the booster nose effects the flow field obviously. In the case of the hemisphere booster nose the pressure has complicate distributions and the separation is very clear. The distance between the booster and main rocket has the evident effect on the flow field. If the distance is smaller the pressure coefficient is bigger the separation zone even the separation bubble occurs. 展开更多
关键词 numerical simulation shock/boundary-layer interaction aerodynamics
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A survey of panel aeroelasticity in shock-dominated flow:Perspectives from fluid-structure interactions and shock wave-boundary layer interactions 认领 引用 被引量：1
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作者 Aiming SHI Yiwen HE 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第1期210-229,共20页
As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises s... As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles. 展开更多
关键词 Aeroelasticity Fluid structure interaction Modal decomposition Shock boundary layer interactions Shock waves
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Modulation of a ramp-induced shock wave/boundary layer interaction through extended frequency range pulsed discharge 认领 引用
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作者 Hongyu WANG Hongxun LI +1 位作者 Gang WANG Tao LI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第5期216-234,共19页
Our experimental study explored the impact of pulse discharge energy deposition,across a wider frequencies ranging from 5 kHz to 20 kHz,on a Shock Wave/Boundary Layer Interaction(SWBLI)at a Mach number of 2.47.Using h... Our experimental study explored the impact of pulse discharge energy deposition,across a wider frequencies ranging from 5 kHz to 20 kHz,on a Shock Wave/Boundary Layer Interaction(SWBLI)at a Mach number of 2.47.Using high-speed schlieren imaging,Planar Laser Scattering(PLS)and Focused Laser Differential Interferometry(FLDI),we analyzed the characteristics of discharge-induced energetic eddies and their impact on SWBLI.The Spectral Proper Orthogonal Decomposition(SPOD)was employed to scrutinize the structural transformations of the flow field under the influence of pulse discharge.Our findings indicate that pulsed discharge significantly alters the flow field by propelling the separation shock upstream,with this effect intensifying as the discharge frequency increases.Additionally,the discharge diminishes the fluctuation intensity of the separation shock and the shear layer,and it reduces the low-frequency spectral energy of the separation shock.SPOD analysis revealed that at high discharge frequencies,the flow field dynamics shift from the low-frequency oscillations of the separation shock to the motion of vortices along the boundary layer,which interact with the shock waves.The control efficacy of pulsed discharge on SWBLI demonstrates remarkable consistency and intensity at frequencies of 10 kHz or higher,whereas a notable attenuation in effectiveness is observed at 5 kHz.This reveals a critical frequency threshold beyond which flow characteristics change markedly,primarily seen in the progressive weakening of the separation shock.However,further frequency increases beyond this point yield diminishing returns in SWBLI control effectiveness. 展开更多
关键词 Flow visualization Plasma flow control Shock wave/boundary layer interaction Supersonic flow Wind tunnel experiments
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BOUNDARY EFFECT ON A STATIONARY VISCOUS SHOCK PROFILES FOR A HYPERBOLIC SYSTEM WITH CATTANEO'S LAW IN A 1D HALF SPACE 认领 引用
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作者 Lili FAN Yinsong BAI 《Acta Mathematica Scientia》 SCIE CSCD 2026年第4期1862-1884,共23页
In this paper,we investigate asymptotic behavior of global solution to the initialboundary value problem of a hyperbolic system with Cattaneo's law on negative half line.Our aim is to prove that the asymptotic pro... In this paper,we investigate asymptotic behavior of global solution to the initialboundary value problem of a hyperbolic system with Cattaneo's law on negative half line.Our aim is to prove that the asymptotic profile of the global solution is exactly the stationary viscous shock wave under suitable smallness condition on initial perturbations and shock strength.The proofs are given by applying an weighted L2-energy method. 展开更多
关键词 Cattaneo's law stationary viscous shock wave initial-boundary value problem weighted L2-energy method boundary effect
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Study of an adaptive bump control mechanism for shock wave/boundary layer interactions in supersonic flows 认领 引用 被引量：2
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作者 Shan-Shan Tian Liang Jin +2 位作者 Wei Huang Yang Shen Kai An 《Theoretical & Applied Mechanics Letters》 EI CAS CSCD 2025年第4期319-330,共12页
The stability of supersonic inlets faces challenges due to various changes in flight conditions,and flow control methods that address shock wave/boundary layer interactions under only one set of conditions cannot meet... The stability of supersonic inlets faces challenges due to various changes in flight conditions,and flow control methods that address shock wave/boundary layer interactions under only one set of conditions cannot meet developmental requirements.This paper proposes an adaptive bump control scheme and employs dynamic mesh technology for numerical simulation to investigate the unsteady control effects of adaptive bumps.The obtained results indicate that the use of moving bumps to control shock wave/boundary layer interactions is feasible.The adaptive control effects of five different bump speeds are evaluated.Within the range of bump speeds studied,the analysis of the flow field structure reveals the patterns of change in the separation zone area during the control process,as well as the relationship between the bump motion speed and the control effect on the separation zone.It is concluded that the moving bump endows the boundary layer with additional energy. 展开更多
关键词 Shock wave/boundary layer interaction Adaptive Flow control Bump Supersonic flow
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Rarefaction effect on non-equilibrium characteristics of laminar shock wave/boundary layer interaction 认领 引用 被引量：1
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作者 Jiahui SONG Long MIAO +4 位作者 Aiguo XU Yanbiao GAN Feng CHEN Yugan LIAO Xiao HOU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2025年第10期311-326,共16页
A Discrete Boltzmann Method(DBM)with a Maxwell-type boundary condition is constructed to investigate the influence of rarefaction on laminar Shock Wave/Boundary Layer Interaction(SWBLI).Due to the complexity of compre... A Discrete Boltzmann Method(DBM)with a Maxwell-type boundary condition is constructed to investigate the influence of rarefaction on laminar Shock Wave/Boundary Layer Interaction(SWBLI).Due to the complexity of compressible flow,a Knudsen number vector Kn,whose components include the local Knudsen numbers such as Knρand KnU,is introduced to characterize the local structures,where Knρand KnUare Knudsen numbers defined in terms of the density and velocity interfaces,respectively.Since first focusing on the steady state of SWBLI,the DBM considers up to the second-order Knρ(rarefactionon-equilibrium)effects.The model is validated using Mach number 2 SWBLI and the necessity of using DBM with sufficient physical accuracy is confirmed by the shock collision problem.Key findings include the following:the leading-edge shock wave increases the local density Knudsen number Knρand eventually leads to the failure of linear constitutive relations in the Navier-Stokes(N-S)model and surely also in the lower-order DBM;the non-equilibrium effect differences in regions behind the leading-edge shock wave are primarily correlated with Knρ,while in the separation region are primarily correlated with KnU;the non-equilibrium quantities D2and D4,2,as well as the viscous entropy production rate SNOMFcan be used to identify the separation zone.The findings clarify various effects and main mechanisms in different regions associated with SWBLI,which are concealed in N-S model. 展开更多
关键词 Rarefaction effects Discrete Boltzmann method Shock wave/boundary layer interaction Thermodynamic non-equilibrium Kinetic theory
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Formation and solute segregation for an asymmetric tilt boundary on{1012}twin boundaries 认领 引用 被引量：6
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作者 Qiang Yang Shuhui Lv +3 位作者 Peng Chen Zefeng Xie Shuo Zhou Xin Qiu 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2025年第2期583-591,共9页
Asymmetric tilt boundaries on conventional twin boundaries(TBs)are significant for understanding the role of twins on coordinating plastic deformation in many metallic alloys.However,the formation modes of many asymme... Asymmetric tilt boundaries on conventional twin boundaries(TBs)are significant for understanding the role of twins on coordinating plastic deformation in many metallic alloys.However,the formation modes of many asymmetric tilt boundaries are hard to be accounted for based on traditional theoretical models,and the corresponding solute segregation is complex.Herein,atomic structures of a specific asymmetric boundary on{1012}TBs were reveled using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM),molecular dynamics(MD)and density functional theory(DFT)simulations.Reaction betweenM dislocations and the{1012}TB can generate a~61°/25°asymmetric tilt boundary.The segregation of Gd and Zn atoms is closely related to the aggregateddislocations and the interfacial interstices of the asymmetric tilt boundary,which is energetically favorable in reducing the total system energy. 展开更多
关键词 Magnesium alloy Transmission electron microscopy Twin boundary Dislocation Segregation
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Scaling analysis and experimental validation for incident shock wave/boundary layer interactions under the influence of gradual expansion waves 认领 引用
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作者 Yunjie GUO Ziyun WANG +5 位作者 Huijun TAN Yue ZHANG Yufeng HUANG Hongchao XUE Hang YU Hao ZHANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2025年第3期207-221,共15页
Cowl-induced incident Shock Wave/Boundary Layer Interactions (SWBLI) under the influence of gradual expansion waves are frequently observed in supersonic inlets. However, the analysis and prediction of interaction len... Cowl-induced incident Shock Wave/Boundary Layer Interactions (SWBLI) under the influence of gradual expansion waves are frequently observed in supersonic inlets. However, the analysis and prediction of interaction lengths have not been sufficiently investigated. First, this study presents a theoretical scaling analysis and validates it through wind tunnel experiments. It conducts detailed control volume analysis of mass conservation, considering the differences between inviscid and viscous cases. Then, three models for analysing interaction length under gradual expansion waves are derived. Related experiments using schlieren photography are conducted to validate the models in a Mach 2.73 flow. The interaction scales are captured at various relative distances between the shock impingement location and the expansion regions with wedge angles ranging from 12° to 15° and expansion angles of 9°, 12°, and 15°. Three trend lines are plotted based on different expansion angles to depict the relationship between normalised interaction length and normalised interaction strength metric. In addition, the relationship between the coefficients of the trend line and the expansion angles is introduced to predict the interaction length influenced by gradual expansion waves. Finally, the estimation of normalised interaction length is derived for various coefficients within a unified form. 展开更多
关键词 Supersonic flow Shock wave/boundary layer interactions Boundary layer separation Scaling analysis Prediction of interaction length
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Three-dimensional curved conical shock wave/plate boundary layer interactions 认领 引用
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作者 Jianrui CHENG Tao ZHANG +3 位作者 Zhenqi SUN Chongguang SHI Chengxiang ZHU Yancheng YOU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2025年第12期32-45,共14页
Three-dimensional curved shock wave/boundary layer interaction with streamwise and spanwise curvatures widely exists in practical aerodynamic design.To explore the effects of composite shock curvatures on boundary lay... Three-dimensional curved shock wave/boundary layer interaction with streamwise and spanwise curvatures widely exists in practical aerodynamic design.To explore the effects of composite shock curvatures on boundary layer separation,a canonical model with a cone placed above plate was utilized as a reference.Configurations of straight,convex,and concave conical shock waves inducing the curved conical shock wave/boundary layer interactions were studied,using CFD based on Reynolds-averaged numerical simulation method.The flow structure and separation region of each case were discussed quantitively on the symmetry plane,flat plate,and plane perpendicular to flow direction,respectively.The focus of the analysis was on the characteristic patterns of separation scale variation in the streamwise and spanwise directions,which were observed to consistently change with respect to both directions with alterations in the incident shock wave shape.A simplified control volume model was established to qualitatively discuss the influence source of curved shock waves on separation scales,based on mass conservation equations.The results suggest that the curved shock wave has a holistic effect on separation,which is not solely dependent on the shock foot strength. 展开更多
关键词 Flow separation Reynolds-averaged Shock waves Shock wave/boundary layer interaction Three-dimensional flow
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High-amplitude wall heat flux events in an impinging shock wave/turbulent boundary layer interaction 认领 引用
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作者 Xianxu YUAN Fulin TONG +2 位作者 Junjie LIMEI Xiangxin JI Xinliang LI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2025年第6期336-348,共13页
This study focuses on High-Amplitude Wall Heat Flux events(HAWHFs) occurring during the interaction between a supersonic flat-plate Turbulent Boundary Layer(TBL) at a Mach number of2.25 and an oblique shock wave impin... This study focuses on High-Amplitude Wall Heat Flux events(HAWHFs) occurring during the interaction between a supersonic flat-plate Turbulent Boundary Layer(TBL) at a Mach number of2.25 and an oblique shock wave impinging at 33.2.. A database from a validated direct numerical simulation is analyzed using conditional averaging and a two-dimensional clustering methodology to elucidate the statistical characteristics of both positive and negative HAWHFs within the interaction region. The results reveal that the interaction considerably affects the temporal attributes of the HAWHFs, leading to an extended lifespan for the positive HAWHFs and an increased interval between the occurrences of negative HAWHFs. The structural characteristics of the identified HAWHFs are delineated based on the evolution of population density, aspect ratio, and both absolute and relative distances throughout the interaction. The joint probability density functions of the relative positioning of two adjacent structures indicate that, away from the reattachment point, the positive HAWHFs align in the spanwise direction, displaying similarities with the negative HAWHFs. Moreover, a conditional analysis of flow structures associated with HAWHFs is conducted. This analysis of the conditionally averaged three-dimensional fields reveals that the interaction fosters larger-scale organizational patterns in the downstream region. However, the formation of positive and negative HAWHFs remains largely unaffected by the interaction, with the former predominantly linked to a two-layer temperature structure and the latter primarily associated with a pair of oblique vortices. 展开更多
关键词 Shock wave Turbulent boundary layer Wall heat flux Extremeevents Direct numerical simulation
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Achieving serrated grain boundaries within gradient microstructures of nickel-based superalloys for dual-property turbine disks in aeroengines 认领 引用 被引量：1
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作者 Bingchao XIE Yongquan NING +4 位作者 Youwei LUO Zhaotian WANG Bowen SHI Mei ZHAN Mingwang FU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第2期641-660,共20页
Gradient microstructures strengthened by serrated Grain Boundaries(GBs)were achieved through a combination of Gradient Strain Deformation(GSD)and Serration Heat Treatment(SHT),with particular focus on microstructural ... Gradient microstructures strengthened by serrated Grain Boundaries(GBs)were achieved through a combination of Gradient Strain Deformation(GSD)and Serration Heat Treatment(SHT),with particular focus on microstructural evolution,underlying mechanisms,and the critical influencing factors.Dynamic recrystallization governed the microstructural evolution in the fine-grained and transition regions during GSD,where multiple nucleation mechanisms were active.Plastic deformation facilitated the dissolution ofγ'phase in fine-grained regions,ultimately resulting in its morphological transformation.During the subsequent SHT,serrated GBs formed within the gradient microstructures produced by prior GSD without disrupting the grain size gradient,thereby enhancing creep resistance.Two distinct mechanisms associated withγ'gbparticles governed the formation of the serrations at GBs.Owing to the stronger dragging effect of grain boundary junctions in fine-grained regions,the amplitude and wavelength of serrations in these regions were smaller than those in coarse-grained regions.Moreover,the formation of serrations exhibited a strong dependence on the inherent properties of the GBs.The random high-angle grain boundaries(HAGBs)with misorientation angles in the range of 30-59°tended to become serrated more easily during SHT due to their high mobility and the accelerated precipitation ofγ'gbparticles at them.Low-ΣHAGBs and low-angle GBs were not prone to form serrations.In particular,serration formation was completely inhibited atΣ3 twin boundaries due to their extremely low mobility and the absence ofγ'gbparticles. 展开更多
关键词 Gradient microstructures Grain boundary migration Grain boundary properties Serrated grain boundaries Serration formation mechanisms Superalloys
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Aerodynamics-informed parametric method for rapid waverider design based on the second-order curved shock theory 认领 引用 被引量：1
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作者 Yiqi TANG Xiaogang ZHENG +2 位作者 Chongguang SHI Chengxiang ZHU Yancheng YOU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第3期1-23,共23页
Waverider design based on osculating theory presents two critical issues:robust specification of design curves and accurate solution of the basic flowfield.Although the existing parametric approaches have advanced rap... Waverider design based on osculating theory presents two critical issues:robust specification of design curves and accurate solution of the basic flowfield.Although the existing parametric approaches have advanced rapid configuration generation through geometric parameterization frameworks,they critically neglect the inherent coupling between aerodynamic constraints and geometric design parameters.To overcome this limitation,an Aerodynamics-Informed Parametric(AIP)method is developed by analytically deriving three waverider design curves and integrating them with the second-order curved shock theory.This method enables rapid waverider surface design while accounting for inflow conditions and shock wave geometry.Three typical waveriders,each featuring distinct combinations of design curves as inputs,are constructed and evaluated through inviscid and viscous numerical simulations to validate the applicability and accuracy of the AIP method.The results indicate that waveriders derived using the AIP method successfully reproduce the preassigned shock waves and original flowfields.Compared to traditional waverider design techniques based on the method of characteristics,the AIP method reduces computation time by approximately 94%,while maintaining errors in the inviscid lift-to-drag ratio,viscous lift-to-drag ratio,and volumetric efficiency below 0.1%,4.0%,and 0.1%,respectively.Additionally,a specially designed model is fabricated for the wind-tunnel tests to analyze the hypersonic aerodynamic performance of the waverider.Both numerical and experimental results confirm the feasibility of the AIP method,making it a promising candidate for waverider design and optimization. 展开更多
关键词 Analytical expressions Curved shock theory Hypersonic vehicles Rapid waverider design
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Prediction method for stationary crossflow instability transition in supersonic boundary layers based on multi-layer perceptron 认领 引用 被引量：2
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作者 Lei Qiao Xi Jiang +5 位作者 Jiakun Fan Yutian Wang Lu Xie Ningjuan Dong Jiakuan Xu Junqiang Bai 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第7期36-51,共16页
Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory ... Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory predictive capabilities for this kind of transition,its practical implementation faces inherent limitations:the requirement of first-and second-order wallnormal derivatives of boundary layer velocityemperature profiles,the need for initial eigenvalue guesses,and the computational burden of solving eigenvalue problems.To address these challenges,this study develops a multi-layer perceptron(MLP)model tailored for linear stability analysis of three-dimensional compressible boundary layers based on the artificially defined quasi-three-dimensional non-similar boundary layer solutions.The boundary layer edge flow parameters and perturbation characteristics are mapped to eigenvalues or local growth rates of the envelop curves through fully connected layers.This architecture eliminates the need for computing wall-normal derivatives of velocityemperature profiles,initial eigenvalue estimation,and direct eigenvalue problem solving.Extensive validation across varying operational conditions and geometries(airfoils and swept wings)demonstrates exceptional agreement between the MLP’s predictions(eigenvalues and disturbance amplification factors)and traditional LST results.Furthermore,the model’s transition prediction capability is rigorously verified using National Aeronautics and Space Administration’s supersonic swept-wing crossflow-dominated transition benchmark,incorporating both stability analysis and flight test data.Results confirm the model is an efficient and reliable computational framework for transition prediction in three-dimensional finite-span wings. 展开更多
关键词 Supersonic swept wing Boundary layer transition Crossflow instability Linear stability theory eN method Multi-layer perceptron
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Achieving strength-ductility synergy of an additively manufactured metastable high-entropy alloy via deep cryogenic treatment followed by laser shock peening 认领 引用 被引量：1
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作者 Zhaopeng Tong Yuze Zhang +4 位作者 Yichen Wang YunXia Ye Jie Yin Yucheng Bao Xudong Ren 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2026年第1期554-572,共19页
Laser powder bed fusion(LPBF)is an attractive additive manufacturing technology for preparing high-performance high-entropy alloys(HEAs)engineering components.Unfortunately,the existence of inherent thermal residual s... Laser powder bed fusion(LPBF)is an attractive additive manufacturing technology for preparing high-performance high-entropy alloys(HEAs)engineering components.Unfortunately,the existence of inherent thermal residual stress and non-equilibrium microstructures in the additively manufactured components results in unsatisfactory mechanical properties.Herein,we propose a novel strengthening strategy,namely deep cryogenic treatment(DCT)followed by laser shock peening(LSP),to tailor the microstructures and enhance performances of an LPBF additively manufactured metastable HEA.The post-treatment effects of DCT+LSP on the LPBF-fabricated Fe50Mn30Co10Cr10HEA are evaluated in terms of microstructural modifications,residual stress,and microhardness redistribution,as well as tensile properties.Results indicate that a gradient heterogeneous structure is formed on the as-built sample surface,featuring gradient variations in grain size,martensitic phase content,and dislocation density,due to the grain refinement and martensitic phase transformation under DCT+LSP.The initial tensile residual stress on the surface is fully transformed into compressive stress,achieving a peak of-289 MPa,and the surface microhardness attains a maximum of 380.8 HV.The various strengthening mechanisms of gradient heterogeneous structures,as well as the multiple effects of heterodeformation-induced(HDI)hardening,transformation-induced plasticity(TRIP),and twinning-induced plasticity(TWIP),are responsible for achieving strength-ductility synergy.This work provides a practical pathway and valuable scientific insights for enhancing the mechanical behaviors of additively manufactured metastable HEAs via microstructural engineering. 展开更多
关键词 metastable high-entropy alloys laser shock peening deep cryogenic treatment gradient heterogeneous structure strengthening mechanisms
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Physics-informed neural networks for hidden boundary detection and flow field reconstruction 认领 引用 被引量：1
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作者 Yongzheng Zhu Weizheng Chen +1 位作者 Jian Deng Xin Bian 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第7期131-149,共19页
Simultaneously detecting hidden solid boundaries and reconstructing flow fields from sparse observations poses a significant inverse challenge in fluid mechanics.This study presents a physics-informed neural network f... Simultaneously detecting hidden solid boundaries and reconstructing flow fields from sparse observations poses a significant inverse challenge in fluid mechanics.This study presents a physics-informed neural network framework designed to infer the presence,shape,and motion of static or moving solid boundaries within a flow field.By integrating a body fraction parameter into the governing equations,the model enforces no-slipo-penetration boundary conditions in solid regions while preserving conservation laws of fluid dynamics.Using partial flow field data,the method simultaneously reconstructs the unknown flow field and infers the body fraction distribution,thereby revealing solid boundaries.The framework is validated across diverse scenarios,including incompressible Navier-Stokes and compressible Euler flows,such as steady flow past a fixed cylinder,an inline oscillating cylinder,and subsonic flow over an airfoil.The results demonstrate accurate detection of hidden boundaries,reconstruction of missing flow data,and estimation of trajectories and velocities of a moving body.Further analysis examines the effects of data sparsity,velocity-only measurements,and noise on inference accuracy.The proposed method exhibits robustness and versatility,highlighting its potential for applications when only limited experimental or numerical data are available. 展开更多
关键词 Hidden moving boundary Flow reconstruction Inverse problem Physics-informed neural networks
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On shock evolution and thrust variation of a rocket permeable nozzle in an ascent-descent operation 认领 引用
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作者 Yuqin Xue Ge Wang +2 位作者 Ben Guan Yuqi Jin Lei Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第3期517-529,共13页
The unique shock pattern evolution and its corresponding thrust variation of a recently proposed rocket permeable nozzle during an ascent-descent operation are investigated using numerical methods.In the present perme... The unique shock pattern evolution and its corresponding thrust variation of a recently proposed rocket permeable nozzle during an ascent-descent operation are investigated using numerical methods.In the present permeable nozzle flow,the flow pattern and shock system evolution are discussed to demonstrate the flow and hysteresis phenomenon.The formation mechanisms of two featured shocks,permeable shock(PS)and detached shock(DS)are interpreted in two typical scenarios.Accordingly,the interconnection between the nozzle thrust coefficient variation and the shock evolution is clarified.New flow characteristics emerge because of the nozzle permeable section.First,the hysteresis phenomenon manifests through the existence-absence of both the Mach disk and PS/DS.Second,the formation mechanisms of PS and DS differ in low nozzle pressure ratio(NPR,38.49-134.19)and high NPR(134.19-322.00)scenarios.In the low NPR scenario,PS is formed by the core flow deflection due to ambient air inflow,and the DS detachment is formed by a mild pressure gradient between inflow and backflow.In the high NPR scenario,the PS is formed by the boundary layer re-development after the outflow-induced expansion wave,and the DS detachment is formed by the outflow-induced pressure gradient reduction.Third,the hysteresis of thrust coefficient variation is essentially manifested in a low NPR range.Notably,the hysteresis of PS/DS existence resides well in that of the thrust coefficient,suggesting that their existence plays a vital role in varying the nozzle thrust coefficient. 展开更多
关键词 Over-expansion Permeable nozzle Shock evolution Detached shock
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Synthesis of gunfire shock signals with controllable SRS and temporal features 认领 引用
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作者 Yinzhong YAN Jianbin RUAN Yulong LI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第3期447-462,共16页
Aircraft-mounted weapons systems generate intense shock and vibration during combat missions,creating a highly complex,repetitive,and nonstationary environment.Avionic devices and components are susceptible to damage ... Aircraft-mounted weapons systems generate intense shock and vibration during combat missions,creating a highly complex,repetitive,and nonstationary environment.Avionic devices and components are susceptible to damage in severe gunfire shock environments and must undergo shock testing.In the absence of measured data,gunfire shock signals synthesized from Shock Response Spectrum(SRS) should serve as input excitation.However,the synthesis of gunfire shock signals presents several challenges,primarily due to the transient and repetitive nature of gunfire shock itself,as well as the inherent non-linearity in the SRS method.This paper presents a novel method for synthesizing gunfire shock signals that match SRS specifications while maintaining realistic temporal characteristics.The proposed method utilizes a shock-waveform dictionary technique to generate single-shot shock signals with controllable features including initial rise time,effective duration,and repetition intervals.These single-shot signals are then duplicated and concatenated to create multi-shot sequences,with low-frequency compensation applied to meet SRS requirements.The method's effectiveness is demonstrated through a case study simulating the M61A1 aircraft cannon firing at 4 000 rounds per minute,achieving an average error of only 0.35 d B compared to SRS specifications.Further validation across two additional cases with varied single-shot durations and repetition intervals underscores the method's generalizability.The proposed synthesis method provides a practical solution for laboratory testing of avionic equipment under gunfire shock conditions when measured data is unavailable. 展开更多
关键词 Gunfire shock environment Shock response spectrum Shock testing Shock-waveform Temporal features
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Progress in shock wave diagnostic technology based on velocity interferometers for laser inertial confinement fusion 认领 引用
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作者 Feng Wang Yulong Li +5 位作者 Zanyang Guan Xiaoshi Peng Xiangming Liu Dong Yang Jiamin Yang Zongqing Zhao 《Matter and Radiation at Extremes》 SCIE EI CAS CSCD 2026年第2期1-13,共13页
Laser-driven inertial confinement fusion(ICF)is an important experimental platform for high-energy-density physics research under extreme conditions.In ICF research,high-quality shock waves are key to fusion energy re... Laser-driven inertial confinement fusion(ICF)is an important experimental platform for high-energy-density physics research under extreme conditions.In ICF research,high-quality shock waves are key to fusion energy release.The velocity interferometer system for any reflector(VISAR)is the most important diagnostic technique for measuring quantities such as shock wave and particle velocities with high precision and high spatiotemporal resolution.This paper provides a detailed introduction to the various configurations of VISAR on 10 and 100 kJ-level laser facilities in China,including Line VISAR,Dual-Axis VISAR,Wide-Angle VISAR,and Compressed Ultrafast Photography-VISAR.Recent advances and applications of VISAR diagnostics at these laser facilities are presented,and the future trend of development of high-spatiotemporal-resolution velocity diagnostic technology is described. 展开更多
关键词 laser inertial confinement fusion high energy density physics velocity interferometer system particle velocities velocity interferometer diagnostic technique shock wave diagnostic technology shock waves
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Characteristics and mechanisms for a new damage region near the loading side of polycrystalline aluminum with helium bubbles under strongly decaying shock waves 认领 引用
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作者 Tingting Zhou Fuqi Zhao +1 位作者 Anmin He Pei Wang 《Matter and Radiation at Extremes》 SCIE EI CAS CSCD 2026年第1期81-92,共12页
The damage evolution of polycrystalline Al with helium(He)bubbles under strongly decaying shock waves is studied by molecular dynamics simulations.A new damage region is observed near the loading side of the sample,an... The damage evolution of polycrystalline Al with helium(He)bubbles under strongly decaying shock waves is studied by molecular dynamics simulations.A new damage region is observed near the loading side of the sample,and the evolution characteristics and underlying mechanisms are elucidated.The development of damage in the new damage region begins after complete unloading of the incident shock wave and is further enhanced when the tensile stress arrives later.The damage evolution is completely controlled by the expansion-merging of He bubbles,without nucleation–growth of voids.This new damage region can be divided into two sections,each of which exhibits a unique dominant mechanism.The damage in the section closer to the loading side is due to the reverse velocity gradient formed after complete unloading of the incident shock wave,depending on the rate of decrease and the amplitude of the initial peak pressure.A high initial peak pressure that can lead to melting of material near the loading side is a necessary condition for the formation of the new damage region,since a significant reverse velocity gradient can only be established if melting occurs.The dominant mechanism in the section distant from the loading side is the action of tensile stress,associated with the profile of the incident shock wave upon reaching the free surface,which determines the material phase near the free surface.Moreover,the presence of He bubbles is another critical factor for formation of the new damage region,which does not occur in pure Al samples. 展开更多
关键词 shock wave polycrystalline aluminum strongly decaying shock waves helium bubbles molecular dynamics simulationsa molecular dynamics simulations tensile stress damage evolution
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