The voluminous stratospheric non-rigid airship is very sensitive to the external thermal environment.The temperature change of internal gas caused by the variation in the external ther-mal environment and wind speed w...The voluminous stratospheric non-rigid airship is very sensitive to the external thermal environment.The temperature change of internal gas caused by the variation in the external ther-mal environment and wind speed will lead to a change in the shape and buoyancy of the airship,thereby affecting its flight control.The traditional static analysis method is difficult to accurately reflect this fuid-thermal-structural coupling process.In this paper,the iterative analysis method was established for the fluid-thermal-structural coupling effect of stratospheric non-rigid airship based on the models of fluid,thermal,and structural deformation.Considering the load such as the internal thermal effect and external flow field of the airship,the simulation of the thermo-induced structural deformation effect was conducted using Fluent and Abaqus software.The influ-ence of local time and external wind speed on the structural deformation,volume,and equilibrium altitude of the airship was analyzed.The results demonstrate that,at low wind speed,the influence of aerodynamic pressure on the deformation of the airship is negligible.However,a great amount of heat is carried away by the wind,then the structural deformation caused by internal and external pressure difference is alleviated and the equilibrium altitude of the airship change obviously.This can serve as a guideline for the design and flight test of the long-endurance stratospheric non-rigid airship.展开更多
The quenching of a metal component with a channel section in a water tank is numerically simulated.Computational fluid dynamics (CFD) is used to model the multiphase flow and the heat transfer in film boiling,nucleate...The quenching of a metal component with a channel section in a water tank is numerically simulated.Computational fluid dynamics (CFD) is used to model the multiphase flow and the heat transfer in film boiling,nucleate boiling and convective cooling processes to calculate the difference in heat transfer rate around the component and then combining with the thermal simulation and structure analysis of the component to study the effect of heat transfer rate on the distortion of the U-channel component.A model is also established to calculate the residual stress produced by quenching.The coupling fluid-thermal-structural simulation provides an insight into the deformation of the component and can be used to perform parameter analysis to reduce the distortion of the component.展开更多
Characterized by the quasi-conically symmetric flow field,κshock wave system,and highly three-dimensional separation structures,the swept shock-wave/boundarylayer interaction(SBLI)induced by sharp fins is one of the ...Characterized by the quasi-conically symmetric flow field,κshock wave system,and highly three-dimensional separation structures,the swept shock-wave/boundarylayer interaction(SBLI)induced by sharp fins is one of the most important phenomena in supersonic flights.An aerothermoelastic analysis is conducted on the interactions between thin-walled panels and swept SBLIs.The results of rigid wall condition,aeroelastic analysis and aerothermoelastic analysis are compared to highlight the significant influence of fluid-thermal-structural interactions on the structure and the flow field of swept SBLIs.The results show that in the aeroelastic analysis,for the material applied to the panel,although a dynamic structural response is observed,the deformation is minor and has a limited influence on the flow field.However,in the aerothermoelastic analysis,the consideration of aerodynamic heating has a significant impact on the structural response and the flow field.The deformation is an order of magnitude larger than that in the aeroelastic analysis with high vibration frequency and various main frequencies at different locations.As a result,the flow field is no longer quasi-conically symmetric.Theλshock wave system and separation structures are completely disrupted by multiple shock and expansion waves induced by the large structural deformation and become much more complex with highly three-dimensional features.This research highlights the significance of investigations on complex three-dimensional aerothermoelastic problems for supersonic flight vehicles.展开更多
基金the National Natural Science Foundation of China (Nos.52302511,52202454,52202513).
文摘The voluminous stratospheric non-rigid airship is very sensitive to the external thermal environment.The temperature change of internal gas caused by the variation in the external ther-mal environment and wind speed will lead to a change in the shape and buoyancy of the airship,thereby affecting its flight control.The traditional static analysis method is difficult to accurately reflect this fuid-thermal-structural coupling process.In this paper,the iterative analysis method was established for the fluid-thermal-structural coupling effect of stratospheric non-rigid airship based on the models of fluid,thermal,and structural deformation.Considering the load such as the internal thermal effect and external flow field of the airship,the simulation of the thermo-induced structural deformation effect was conducted using Fluent and Abaqus software.The influ-ence of local time and external wind speed on the structural deformation,volume,and equilibrium altitude of the airship was analyzed.The results demonstrate that,at low wind speed,the influence of aerodynamic pressure on the deformation of the airship is negligible.However,a great amount of heat is carried away by the wind,then the structural deformation caused by internal and external pressure difference is alleviated and the equilibrium altitude of the airship change obviously.This can serve as a guideline for the design and flight test of the long-endurance stratospheric non-rigid airship.
文摘The quenching of a metal component with a channel section in a water tank is numerically simulated.Computational fluid dynamics (CFD) is used to model the multiphase flow and the heat transfer in film boiling,nucleate boiling and convective cooling processes to calculate the difference in heat transfer rate around the component and then combining with the thermal simulation and structure analysis of the component to study the effect of heat transfer rate on the distortion of the U-channel component.A model is also established to calculate the residual stress produced by quenching.The coupling fluid-thermal-structural simulation provides an insight into the deformation of the component and can be used to perform parameter analysis to reduce the distortion of the component.
基金supported by the National Natural Science Foundation of China(Grant No.12302229,and No.12272354)the Youth Talent Support Program of Henan Province(Grant No.2025HYTP025)+1 种基金the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20232400)the Key Research Project Plan of Higher Education Institutions in Henan Province(Grant No.25A590004)。
文摘Characterized by the quasi-conically symmetric flow field,κshock wave system,and highly three-dimensional separation structures,the swept shock-wave/boundarylayer interaction(SBLI)induced by sharp fins is one of the most important phenomena in supersonic flights.An aerothermoelastic analysis is conducted on the interactions between thin-walled panels and swept SBLIs.The results of rigid wall condition,aeroelastic analysis and aerothermoelastic analysis are compared to highlight the significant influence of fluid-thermal-structural interactions on the structure and the flow field of swept SBLIs.The results show that in the aeroelastic analysis,for the material applied to the panel,although a dynamic structural response is observed,the deformation is minor and has a limited influence on the flow field.However,in the aerothermoelastic analysis,the consideration of aerodynamic heating has a significant impact on the structural response and the flow field.The deformation is an order of magnitude larger than that in the aeroelastic analysis with high vibration frequency and various main frequencies at different locations.As a result,the flow field is no longer quasi-conically symmetric.Theλshock wave system and separation structures are completely disrupted by multiple shock and expansion waves induced by the large structural deformation and become much more complex with highly three-dimensional features.This research highlights the significance of investigations on complex three-dimensional aerothermoelastic problems for supersonic flight vehicles.
