Energy spectrum analysis of compressible flow based on MHz-PIV

High-speed flows have consistently presented significant challenges to experimental research due to their complex and unsteady characteristics. This study investigates the use of the megahertz-frequency particle image velocimetry (MHz-PIV) technique to enhance time resolution under high-speed flow conditions. In our experiments, five high-speed cameras were utilized in rapid succession to capture images of the same measurement area, achieving ultra-high time resolution particle image data. Through advanced image processing techniques, we corrected optical distortions and identified common areas among the captured images. The implementation of a sliding average algorithm, along with spectral analysis of the compressible turbulent flow field based on velocity data, facilitated a comprehensive analysis. The results confirm the capability of MHz-PIV for high-frequency sampling, significantly reducing reliance on individual camera performance. This approach offers a refined measurement method with superior spatiotemporal resolution for high-speed flow experiments.