Unsteady Pressure-Sensitive Paint Measurement forOscillating Shock Wave in Supersonic Nozzle

摘要

Unsteady PSP measurement using fast-response anodized aluminum PSP was applied to an internal flow in a supersonic nozzle to evaluate the performance of unsteady PSP measurement system. This flow has unsteady pressure field caused by traveling shock wave system from downstream to upstream with oscillation. The principle hardware of unsteady PSP measurement system was a high-speed camera and a high-power laser as illumination light source. It was observed by shadow graph method first to understand the brief flow structure, then, the unsteady pressure field was measured as 2 kfps time-series data. PSP pressure sensitivity had nonuniformity so that the local on-site calibration was necessary to process quantitative pressure value. Unsteady PSP results acquired the time-series behavior of pressure field caused by the traveling shock waves system. 100 fps borescope measurement was also applied to same unsteady flow field to check the future extension of internal flow measurement. It was confirmed that the present unsteady PSP measurement system had good performance to apply it to unsteady internal flow field such as engine intake, duct flow, and so on.