SHOCK TUNNEL FLOW VISUALIZATION USING PLANAR LASER-INDUCED FLUORESCENCE IMAGING OF NO AND OH

Temporal sequences of planar laser-induced fluorescence (PLIF) images of several high-speed, transient flowfields created in a reflection-ty pe shock tunnel facility were acquired. In each case, the test gas con tained either nitric oxide or the hydroxyl radical, the fluorescent sp ecies. The processes of shack reflection from an endwall with a conver ging nozzle and of underexpanded free jet formation were examined. A c omparison was also made between PLIF imaging and shadow photography. T he investigation demonstrated some of the capabilities of PLIF imaging diagnostics in complex, transient, hypersonic flowfields, including t hose with combustion.