物体穿越斜激波干扰特性的数值研究

Numerical simulation of interactive flowfields about an missile crossing a oblique shock wave

当物体以超声速穿越同向运动的斜激波时 ,它的飞行 Mach数和攻角都会发生较大的变化。穿越过程中斜激波与物体脱体激波发生相互作用 ,形成复杂的激波干扰波系结构 ,基本的干扰形式为复合 Mach反射结构。不同的穿越位置时 ,由于不同的来流条件 ,使物体上尾部凹坑内的流场和波系发生很大的变化。随着物体的穿越过程 ,当头部和凹坑下游壁面与翼面穿越激波时 ,阻力系数有两次剧烈的变化 ,法向力基本呈线性下降 ,压力中心先大幅度后移 ,物体逐渐穿过激波后又快速前移。因此穿越过程使物体加速 ,给物体的姿态带来很大的扰动。翼面穿过激波也造成阻力、法向力下降 ,压心后移。如果对有控制的飞行器 ,穿越激波时气动力特性和稳定性的急剧变化 。

When a missile crosses a oblique shock wave (OSW) moving in the same direction,its flying Mach number and angle of attack will change very much.In the crossing process,the OSW interacts with the detached shock wave of the missile,and the complex interaction wave system is formed.The basic interactive form is Mach reflection structure.The flowfields and wave system in cave on aft body also change very much with the different inflow condition and various locations of OSW.When the missile across the OSW,the drag changes rapidly in two locations,one is the location OSW over the head region of the missile,the other is over the cave and the tailor.The pressure center moves downstream a lot firstly,and then moves upstream rapidly.Therefore the crossing process makes the missile accelerate and produce a large disturbance to the attitude of the missile.For controllable vehicle,the rapid change of aerodynamic forces and stability from the crossing OSW will bring great difficulty for control system.