Slipper Wear/Gouging Phenomena

The objective of this work is to develop analytical techniques to characterize wear and gouging phenomena of slippers at speeds up to hypersonic and demonstrate means to evaluate or reduce slipper wear/gouging. Specifically, we will develop analytical techniques that can be used to predict slipper wear patterns and gouging phenomena throughout the sled velocity regime to Mach 10. This will include characterizing bearing and aerodynamic pressure distributions, aerodynamic and friction heating and material wear resistance. The key to understanding the damage mechanism is the understanding of the aerodynamic loads and shock structure inthe slipper/rail system. These high speed shock environments are best defined using a compressible fluid dynamic code. We will use the Applied Research Associates, Inc. Second order Hydrodynamic Advanced Research code (SHARC) to define the full 3-dimensional aerodynamic forces on the slipper at several velocities from 5200 feet per second to Mach 10. The results of these calculations will provide insight into any shock structure in the region of the slipper and the changes in the shock structure with increasing velocity which may cause local heating or force imbalance within the slipper/rail geometry.