Thermal and Melt Wear Characterization of Materials in Sliding Contact at High Speed.

摘要

The Holloman High Speed Test Track is used to evaluate hypersonic aircraft materiel in a near-operational environment. The four-stage pusher rocket sled is capable of accelerating a test apparatus to hypersonic speeds in a matter of seconds. The sled must contend with tremendous thermal, mechanical, and aerodynamic loading during each run. The effects of the combination of forces acting on the sled are most acute at the interface between the rail and the wraparound slipper that holds the sled to the rail. Frictional heating due to sliding contact between the slipper and the rail coupled with mechanical wear can lead to significant material degradation in the slipper. Aerodynamic heating can exacerbate deleterious wear effects. This work considers the application of thermal and aerodynamic loading on the slipper. A two-dimensional finite element model is employed to depict temperature distribution and estimate melt wear over the course of a test run. The thermal load cases considered allow a new perspective on the slipper wear phenomena and should serve as a building block in future research endeavors.