基于局部粒子投放的压缩拐角激波/边界层干扰流动控制研究

Compression Corner Shock Wave/Boundary Layer Interaction Flow Control Based on Local Particles Injection

关键词:  局部粒子投放  激波/边界层干扰  流动分离  流动控制  数值模拟

Key words:  Local particles injection  Shock wave/boundary layer interaction  Flow separation  Flow control  Numerical simulation

摘要:

为探究局部粒子投放这种新型流动控制方法在控制激波/边界层干扰（SWBLI）诱导分离上的可行性，针对二维压缩拐角模型，利用数值模拟的方法探究了局部粒子投放对于SWBLI诱导分离的控制机理与控制规律。结果表明：在分离区上游壁面注入的固体粒子会给近壁低速流体注入动量，使分离区上游边界层形状因子减小；同时，由于波后粒子的弛豫效应，粒子也会进一步给流体注入动量。在以上两个因素的共同作用下，SWBLI诱导分离的尺寸得到了显著减小。研究结果还表明：投入的粒子无量纲流量S_L越大（以基准流场边界层流量为参考），粒径D_P越小，所获得的分离控制效果越好。在使用S_L=0.12，D_P=0.5μm的TiO₂粒子进行流动控制时，分离点和再附点间的无量纲流向距离由未控制时的4.85缩减为控制后的1.77，后者仅为前者的36.5%，控制效果良好。

Abstract:

In order to explore the feasibility of the new flow control method of local particle injection in controlling the separation induced by shock wave/boundary layer interaction （SWBLI）， in this paper， aiming at the 2D compression corner model， the numerical simulation method was used to explore the mechanism of controlling SWBLI-induced separation by local particle injection. The results show that the solid particles injected upstream of the separation zone will inject momentum into the low-velocity fluid near the wall， making the shape factor of the boundary layer smaller. At the same time， due to the relaxation effect of the particles behind the shock wave， the particles will also inject momentum to the fluid. Under the combined effect of the above two factors， the separation region’s size was significantly reduced. The current study also shows that the larger non-dimensional mass flow S_L of the input particles （taking the boundary layer mass flow of the baseline case as a reference） and the smaller particle size D_p， the better control effect will be obtained. When using TiO₂ particles with S_L=0.12 and D_p=0.5μm for flow control， the non-dimensional streamwise distance between the separation point and the reattachment point reduces from 4.85 to 1.77， the latter is only 36.5% of the former， which shows the effectiveness of this method.