AERODYNAMICS OF THE HYPERSONIC SLIPPER BEARING,
Abstract
With rocket-boosted sleds on test tracks accelerated to several thousand feet per second, their rail-guided supporting slippers are exposed to severe aerodynamic heating and friction. The slippers are usually wrapped around the rail for support in lateral directions with allowance for a small gap between the two. Air flowing through the gap is shock-compressed to high pressures and temperatures resulting in high heat rates to the inner surface of the slipper. Although the motion of sled and slipper is complex, as a first approximation the slipper flow is studied for a steady state configuration assuming locally two-dimensional flow as the gap height is small compared with lateral dimensions. The flow model consists of a laminar stagnation region at the leading edge of the slipper followed by separate turbulent boundary layers on slipper and rail (shock-tube type) eventually merging into a full shear layer which tends toward a Couette flow asymptote. Heat rates and pressure distributions along the gap are estimated for atmospheric conditions in the speed range from Mach number 4 to 10. It is found that heat rates on the inner surface of the slipper are of the same order as those at the stagnation point for practical leading edge radii, and these are as high as any encountered on actual re-entry vehicles. Furthermore, the configuration is found to be statically unstable causing the gap to collapse or widen when perturbed from equilibrium. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1968
- Accession Number
- AD0675186
Entities
People
- Robert H. Korkegi
- Ronald A. Briggs
Organizations
- Air Force Research Laboratory