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
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.
