Abstract
Temperature Sensitive Paint was used in a Mach 4 Ludwieg tube to detect streamwise vortices shedding from a roughness element. The TSP used in this experiment was Tris(2,2'-bipyridyl) dichloro-Ruthenium(II) hexahydrate, Ru(bpy) in clear cote. The TSP was calibrated using a 4 th order polynomial fit. The camera shutter was opened prior to the start of the tunnel run, and the TSP was excited using a blue LED. The test model was an axisymmetric scramjet inlet model with two compression corners, although the second corner was completely neglected. Two locations for the roughness elements were tried; one close to the nose, and another just upstream of the first compression corner. The effect of each roughness was investigated one at a time. The first roughness created a wake region behind the roughness, which did not give a clear image of streamwise vortices. The second roughness created a pair of well-defined vortices shedding from the roughness element. Neither of the roughness caused transition to occur within the region captured by the camera. © 2002 by the author(s).