Influence of Surface Roughness on the Shock Transition in Quasi-Stationary and Truly Non-Stationary Flows,

Abstract : The effect of surface roughness on the shock transition over flat wedges in quasi-stationary flows is examined experimentally. For flat wedges saw-toothed roughnesses a mesh No. 40 sand paper and a mesh No. 320 sand paper were used. Experiments were conducted on the Institute of High Speed Mechanics 40 mm x 80 mm shock tube equipped with a double exposure holographic interferometer. The incident shock Mach number range was 1.04 to 4.0 for nitrogen or dry air. In the case of curved wedges, the shock transition angles were determined by means of streak camera technique with curved slits.