Studies of Boundary Layer Transition and Surface Roughness Effects in Hypersonic Flow
Abstract
The first of the studies was a detailed experimental investigation of the effects of the shape and spacing of roughness elements on a maneuverable re- entry vehicle configuration on the roughness-enhanced heating and skin friction. Measurements were made on slender cones and control flaps to define the relationships between roughness-element shape and spacing and the incremental heating and skin friction induced by the surface roughness. It was demonstrated that similar measurements in subsonic flows cannot be directly extrapolated to predict trends in high-speed compressible flows. In the second study, the transition process in the stagnation region of a blunt body in hypersonic flows was examined in detail. The main focus was on determining what fluid-dynamic mechanics are responsible for enhanced heating in the stagnation region of high Reynolds number blunt-body flows. Investigated was whether upstream influence from transition, surface roughness in the stagnation region, minute dust particles interact with the shock layer ahead of a blunt body. The resulting considerable increases in stagnation heating were linked with the shear layers generated by particle-shock/bow-shock interactions and the tripping of the boundary layer in the stagnation region as each dust particle enters it. In the fourth study, microsecond photographs and high-frequency thin-film measurements on slender cones were used to examine breakdown of flow in and preceding the hypersonic boundary layer transition region. The results obtained provide insight into the mechanisms by which the laminar/turbulent boundary becomes unstable in high-speed boundary layers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1983
- Accession Number
- ADA140803
Entities
People
- M. S. Holden
Organizations
- Calspan