COMPUTATIONAL INVESTIGATIONS OF THE EFFECTS OF WALL SURFACE TEMPERATURE ON A HYPERSONIC INLET ISOLATOR

Flow and shock train development in a hypersonic inlet isolator at various wall surface temperatures, Tw, w , and freestream static temperatures, T infinity, infinity , were studied through numerical simulations. A non-dimensional parameter, Tw w /T infinity, infinity , is used to characterize flow behaviors in hypersonic isolator. With the increase of Tw w /T infinity, infinity , boundary-layer thickness increases and boundary-layer momentum thickness decreases at the entrance of isolator. Inside the isolator without the presence of backpressure, skin friction decreases with the increase of Tw w /T infinity. infinity . The main cause is a lower velocity gradient near the wall at high temperature. A lower skin friction on high wall temperature results in a stronger separation with shock impingement. Under backpressure conditions, with the increase of Tw w /T infinity, infinity , an upstream movement of the starting position of the shock train inside the isolator, an increase in the length of the shock train, and an increase in pressure coefficient on the wall surface are observed.