Comprehensive Design And Mechanical Investigation Of Novel Impact Piston Of Gun Wind Tunnel

The gun wind tunnel can generate hypersonic flow field which is a very important aerodynamic ground test device for developing hypersonic weapon.As one of the important components of the gun wind tunnel,its comprehensive design quality not only directly affects the wind tunnel test data,but also decides the cost of the piston,and its service life is directly related to the wind tunnel operation cost.Due to the complicated working conditions of the gun tunnel piston,the theoretical analysis of the piston structure brings great difficulties.Therefore,under the given dimensions,quality and working conditions,it is of great research value and engineering significance to study the static mechanical properties of the piston,analyze the impact dynamics of the piston and to develop a new type of piston structure.Firstly,according to the topology optimization method,the structure type of the main bearing part of the structure is preliminarily determined,and the conceptual design scheme of the piston structure is put forward based on the constraint conditions.Through analysis and comparison of conceptual design scheme,the detailed design and calculation of the main bearing part and the skirt part of the piston structure are carried out,and the integrated design concept of the piston structure skirt part and the main body pressure part is put forward.Then,based on the configuration design scheme of the new piston structure,a new finite element model of static load analysis of piston structure is established.The bearing capacity of the main bearing part of the piston and the radial lateral pressure resistance of the skirt are analyzed to verify the static bearing characteristics of a new piston structure.Finally,the natural frequency,modal and other vibration characteristics of the new piston structure were studied,the harmonic response law of the structure was analyzed,and the nonlinear dynamic model of the piston structure was established.,and the dynamic response law of the new piston structure impacting the rigid wall forward is emphatically studied,especially the change process of the structure stress,strain and energy with time.Compared with the original piston,the rationality and validity of the existing piston structure design are verified.Meanwhile,by establishing the mechanical model with the buffer device,it is found that the damping device can effectively protect the piston structure,and the influence law of the damping device parameters on the dynamic response of the piston structure has been discussed.The research shows that the new piston structure,on the one hand,improves the comprehensive structural strength of the piston structure and is expected to reduce the cost of the gun wind tunnel,on the other hand,this paper provides an important theoretical basis and reference for the subsequent optimization design of the piston structure of the gun wind tunnel.