Research On Pneumatic Regulation Technology Of Hypersonic 2-D Curved Shock Inlet

In order to meet the normal flight demand of hypersonic vehicle working in the wide mach range,hypersonic inlet needs to minimize the starting mach number on the premise of guaranteeing working performance.Based on the hypersonic 2-D curved shock inlet,a pneumatic adjustment technology is developed to control the compression surface deformation by using the aerodynamic force of the elastic compression surface.Compared with the traditional regulation method of using motor and mechanical transmission mechanism for adjusting the geometry,the aerodynamic adjustment technology studied in this paper directly uses the aerodynamic force of the flow field as the driving force to make the surface deformed,greatly reducing the quantity and quality of the inlet adjusting device,worthy of further research into.There is a two-way coupling between the flow field and the elastic compression surface during the aerodynamic adjustment.This paper first gives a brief introduction to the solving method of two-way fluid solid coupling problem.The theoretical solution method needs the linear simplification of the model,the solution has the limitation,the test method cost is high,so this paper mainly uses the numerical simulation method to carry on the research.ANSYS workbench software has high reliability for solving solid and fluid problems,and data transfer between multiple physical fields is simple.Therefore,this software is used to do research on pneumatic control technology.According to the concept of aerodynamic adjustment technology,a pressure cavity scheme with uniform load under the surface of the elastic compression surface is designed based on the 2-D curved shock inlet with the design point of Ma=6.The numerical simulation of the two-way fluid solid coupling model is carried out and the results show that:The pressure cavity inlet can make inlet start at Ma=3,the deformation step phenomenon of the elastic compression plane and the starting hysteresis exist during the starting process;The variable thickness design of the elastic compression plane can effectively improve the mass flow rate and the outlet pressure ratio of the inlet in the starting state at Ma=3.The pressure cavity scheme keeps the performance of the inlet at the design point Ma=6,and also improves the mass flow rate and the outlet pressure ratio at the non-design point Ma=4.Finally,one other elastically deformable scheme of inlet's compression surface with concentrating force was researched on the basic of the single pressure cavity scheme.The numerical results show that:The concentrating force scheme can also make the inlet start at Ma=3;A scheme with only a single concentrated force acting on the lower surface of elastic compression surface is better than multiple concentrating forces in the performance of the Ma=3.By setting the displacement constraint in the external section of the inlet,we can more precisely control the compression face shape after deformation,further improve the mass flow rate and outlet pressure ratio.The numerical simulation under other flight conditions proves that the single concentrated force improvement scheme can also maintain the performance at the design point,and increase the mass flow rate and outlet pressure ratio at the non-design point.