Effect of Clearance between Two-Body on Heat Flux in Hypersonic Compression Ramp

다국어 초록 (Multilingual Abstract)

The hypersonic flow over a compression ramp is one of the most important problems, where various phenomena occur, such as shock/shock interaction, shock boundary layer interaction, and reattachment of separated boundary layer. Consequently, heat flux and pressure around the corner become high. Actually these phenomena appear in the body flap and wing root of space shuttle. Furthermore, a severe problem such as Columbia takes place when these interactions occur in a crack, as a result of thermal protection tiles damage. The objective of the present study is to experimentally investigate heat flux near the corner of a compression ramp at hypersonic speed. The present two-dimensional compression ramp is consisted of two flat plates. Hence the flow-field is assumed to be nearly two-dimensional. The deflection angle of the corner is fixed at 30 deg. All experiments were performed in the shock tunnel of Nagoya University. The diameter of the nozzle exit is 350㎜, which can produce a hypersonic flow with a Mach number of8.1, where the duration is 50msec. The unit Reynolds number is Re=6.5x10?m?¹. In addition, the effect of the clearance h between the two bodies on the flow-field is examined by measuring distributions of the heat flux. From shclieren images. the flow-field can be classified into two patterns. In the case of no clearance (h/L=0.00), the shear layer generated from upstream of the corner reattaches on the ramp, where heat flux rises in the downstream of the reattachment region. The heat flux is almost same as the stagnation heat flux. In the case of small clearance (h/L=0.025), the reattachment point moves upstream of the ramp, although the large separation region does not change. In the case of a large clearance (h/L=0.050). the separated boundary layer does not reattach on the ramp, and goes into the clearance.

목차 (Table of Contents)

• Abstract
• 1. Introduction
• 2. Experimental set up
• 3. Results and discussion
• 4. Summary
• REFERENCES