Hydroxyl Tagging Velocimetry in a Mach 2 Flow With a Wall Cavity (Postprint)

摘要

Hydroxyl tagging velocimetry (HTV) measurements of velocity were made in a Mach 2 flow with a wall cavity. In the HTV method, ArF excimer laser (193 nm) beams pass through a humid gas and dissociate H2O into H + OH to form a tagging grid of OH molecules. In this study, a 7x7 grid of hydroxyl (OH) molecules is tracked by planar laser-induced fluorescence. The grid motion over a fixed time delay yields about 50 velocity vectors of the two-dimensional flow. Instantaneous, single-shot measurements of two-dimensional flow patterns were made in the non-reacting Mach 2 flow with a wall cavity under low and high pressure conditions. The single-shot profiles were analyzed to yield mean and rms velocity profiles in the Mach 2 non-reacting flow.