The Development Of Oblique Shock Wave In Confined Channel And Its Influence On The Flow Process

In recent years,with the rapid development of science and technology,hypersonic vehicles have got the attention of various countries.As a new scramjet engine,they are faced with many great problems in the development process.The phenomenon of oblique shock in the combustion chamber is one of the main problems.It is the main content of this paper to understand the development of the oblique shear wave and the influence on the combustion of the combustion chamber.In this paper,a simplified open cavity is used as the main model,and the three-dimensional oblique shock wave is simulated based on the two-dimensional oblique shock theory.In order to avoid the influence of the viscous surface layer on the flow,the simulation is mainly for the ideal situation,that is,the fluid flow process is not sticky,so the solid wall boundary conditions and periodic boundary conditions are similar,there is no velocity in the tangential direction of the combustion chamber.The following conclusions are obtained by numerical simulation: For the ?-shaped cavity,the three-dimensional oblique shock generated at the leading edge of the cavity and presents a three-dimensional twisted shock wave surface,and both sides of the wall and the cavity generated by the middle of the shock shape is not the same and irregular,but there is not much research at the moment.In order to explore the cause of this phenomenon,the effect of the gas flow in the cavity and the effect of the boundary layer on the oblique shock wave are neglected.It is found that in order to satisfy the boundary condition of the wall flow,when the three-dimensional shock wave surface intersects the wall surface,the shock wave intensity is weakened,and the normal direction of the shock wave surface is perpendicular to the normal direction of the wall surface.,and when the shock wave surface and the wall intersection into an acute angle,it will produce conventional reflection or Mach reflection.Then we explore the Mach reflection phenomenon in the three-dimensional oblique shock wave,and find that the Mach reflection is directly related to the airflow deflection angle,for Mach stem in the Mach reflection,the influence factors are more.The width of the model and the deflection Angle can affect the production of the Mach stem and the length of the Mach stem.In this paper,through the study of the restricted channel in the development of oblique waves and its impact on the flow process,we hope to guide the design of the combustion chamber so that the fuel will be effectively blended by the oblique shock effect.As a result,the combustion efficiency is improved.