SHOCK WAVE INTERACTION NEAR A CYLINDER ALIGNED NORMAL TO A BLUNTED PLATE—PART I: GAS FLOW AND HEAT TRANSFER ON A PLATE NEAR A CYLINDER

Abstract

The flow around a cylinder mounted on a sharp or blunted plate is experimentally studied. The experiments are performed in a shock tunnel at Mach number M∞ = 5 for a wide range of Reynolds numbers ReL (based on the plate length): from 0.6 to 3.4 × 107. The varied parameters are the distance between the leading edge of the plate and the cylinder X0 and the bluntness radius of the leading edge of the plate. A panoramic method is used to investigate heat transfer. The work consists of two parts. Part I describes the results on the flow structure and heat transfer on the plate surface ahead of the cylinder and in its vicinity. It is shown that the heat transfer coefficient near the cylinder is significantly greater than that on the plate in the undisturbed region and is close in terms of the order of magnitude to the heat transfer coefficient on the frontal surface of the cylinder in the undisturbed flow. An increase in the bluntness radius of the plate to a certain level considerably decreases the maximum Stanton number ahead of the cylinder. At the transitional and turbulent states of the undisturbed boundary layer on the plate ahead of the cylinder, the change in the Reynolds number in the examined range has a minor effect on heat transfer enhancement near the cylinder on both the sharp and blunted plates. Investigations of the state of the boundary layer on the plate, which is not disturbed by the cylinder, confirm the existence of a reverse laminar–turbulent transition, which occurs when the bluntness radius increases. It is shown that the laminar–turbulent transition and its reverse transition lead to nonmonotonic changes in the peak Stanton number on the plate as a function of the bluntness radius of the leading edge and the distance between the leading edge and the cylinder.