Design And Research Of Heat Flow Test Mechanism In Hypersonic Wind Tunnel

When the hypersonic wind tunnel performs the heat flow test,in order to avoid the measurement error caused by heating before the model is put into specific location,the test-modle is required to quickly send into the middle of the flow field and stably stop at the designated position.Therefore,a set of heat flow measurement is designed and its performance was studied.The heat flow measurement test mechanism is designed as a layered series mechanism mainly composed of an X-axis motion mechanism,a Y-direction motion mechanism,a yaw angle adjustment mechanism and a pitch angle adjustment mechanism.The motion performance of the Y-direction mechanism is the key and difficult point in the heat flow measurement test of the hypersonic wind tunnel to obtain reliable experimental data.In this paper,according to the design index of the hypersonic tunnel heat flow measurement experiment institution,the structure and the movement of the heat flow measurement test mechanism in the hypersonic wind tunnel at domestic and overseas are studied and referred to at the same time.The structure of the hypersonic wind tunnel model heat flow measurement test mechanism is proposed.Also,the realization methods and techniques for their respective degrees of motion functions were determined.Aiming at the time requirement and the motion characteristics of the Y-direction motion,an innovative drive sczeme for the linear motor was proposed.The improved trigonometric acceleration/deceleration control algorithm and S-type acceleration/deceleration control algorithm are respectively used to plan and design the Y-direction motion trajectory.The advantages and disadvantages of the two algorithms are compared and analyzed.The S-type acceleration/deceleration control algorithm for the subject is selected for fast feed motion trajectory planning of the Y direction.The three-dimensional parametric modeling of the heat flow measurement mechanism was performed,and the workbench software was used to analyze the static and dynamic characteristics of the mechanism.The static and dynamic performance of the mechanism is obtained to meet the design requirements.The parameters of the weakest link in the heat flow measurement mechanism stiffness were identified,and then the weak link was optimized based on the sensitivity.The heat flow measurement test instrument was lightweight,and the static and dynamic performance of the mechanism that after optimization was compared with the original performance.The heat flow measurement test facility developed in this project meet the requirements of a hypersonic wind tunnel experiment.In the structural design,the spatial reuse principle and the CAE optimization design method were used to light weight,aslo improve the rigidity and sports performance of the measurement facility.The trajectory planning for the Y-direction movement is reasonable and practical,which provides a reference for the wind tunnel heat flow measurement test institution.