Laminar-turbulent flow around a wedge placed on sharp and blunted plates

Abstract

The §ow structure and heat transfer on sharp and blunted plates near a wedge have been studied experimentally at Mach number 6 and two Reynolds numbers corresponding to laminar and transitional boundary layers ahead of the wedge. Similarly to the two-dimensional (2D) §ow, the plate£s blunting causes a decrease of heat transfer at threedimensional (3D) interference between the boundary layer and the shock wave. However, there is a threshold bluntness value beyond which the in §uence is negligible. Heat transfer and pressure measurements as well as surface §ow visualization have been performed by means of panoramic (global) methods based on the use of luminescent coatings. They have been used in a short duration (pulse) wind tunnel for the ¦rst time.

Three-dimensional shock-wave/boundary-layer interaction at the presence of entropy layer

“…The measurement methods are described in details earlier [12,13]. In the present work, the technology of TSP and PSP application is modi¦ed to provide the observation of the entire plate surface.…”

“…It can be seen that at all the investigated ¦n angles, the plate blunting reduces the heat transfer near the ¦n in an equal degree. A signi¦cant reduction of the heat transfer occurs at the increase of the plate bluntness radius only up to r/X 0 ≈ 0.010 0.015, i. e., at the turbulent state of the undisturbed boundary layer, the stabilization of the ratio St m /St ms occurs at smaller relative bluntness radius than at the laminar and transient states of the boundary layer (0.02 0.03) [12,13].…”

“…The in §uence of slight blunting on the gas §ow and the heat transfer in the region of interaction between a single ¦n and the plate at Mach number í = 6 and Reynolds numbers Re ∞L up to 19.2 · 10 6 was investigated in [12]. The undisturbed boundary layer ahead of the ¦n was laminar or transitional.…”