Assessment of streamline-based pressure reconstruction for PIV data in supersonic flows with shock waves

In this paper, a streamline-based (SLB) pressure reconstruction method for particle image velocimetry (PIV) data, which has great potential to reduce the error propagation across relatively strong shock wave (compared with the conventional spatial integration method) and decrease computation cost and operation difficulty [compared with the MacCormack method (Liu et al. 2017, 2019)] in supersonic flows, is comprehensively analyzed and evaluated by numerical and experimental velocity fields. First, the theoretical error model caused by particle relaxation is built by an oblique shock wave. Then, the feasibility of this method in five typical kinds of shock flows is verified based on a simulated Mach interaction velocity field generated by two wedges of 17° and 22°. Besides, the effects of random velocity error, streamline resolution, velocity spatial resolution and out-of-plane component on the pressure reconstruction are also analyzed in detail. Finally, the PIV measurements of oblique and bow shock waves with a free stream Mach number of 2.91 are conducted for experimental validation. These results confirm the feasibility, robustness and good accuracy of the SLB method in supersonic flows with relatively strong shock waves.