Reusable high temperature thermal protection system

Abstract

A reusable phase change material (PCM) heat shield is disclosed. The heat shield comprises: a thermally conductive casing, PCM, thermally conductive open cell foam, and heat pipes. The heat flows through the casing and open cell foam into the PCM, heating it up. The PCM changes phase twice, from solid to liquid. During the solid liquid phase change, heat pipes begin to draw heat away from the PCM to a secondary location that re-radiates the heat away. The open cell foam serves to help channel hear into the PCM. In one embodiment, the PCM heat shield can be used for thermal protection of an atmospheric entry vehicle (ARV). In another, the PCM heat shield may be applied to an aircraft engine to transfer extracted heat to preheat incoming air. In another, the PCM heat shield is integrated into the structure of a spacecraft, and used to both carry loads and protect against high temperatures.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Under 35 USC 119(e), this application claims the benefit of U.S. Patent Application Ser. No. 61 / 347,759, entitled “REUSABLE HIGH TEMPERATURE THERMAL PROTECTION SYSTEM,” filed on May 24, 2010, which is incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates generally to heat shields and more particularly relates to a thermal protection method and system for heat shields.BACKGROUND OF THE INVENTION[0003]Heat shields are used in the aerospace industry for vehicles and engines that operate in high temperature environments. The state of the art in aerospace heat shields is radiative protection. Utilizing a material that has extreme high temperature resistance, high thermal conductivity, and high emissivity, this material is applied to the leading edge or nosecone of a vehicle. The heat that is generated there gets transferred into the material, and then conducted up the vehicle, before being radiated out at a...

AI Technical Summary

Benefits of technology

[0006]In one embodiment, the PCM heat shield can be used for thermal protection of an atmospheric entry vehicle (ARV). In another, the PCM heat shield may be applied to an aircraft engine to transfer extracted heat to preheat incoming air. In another, the PCM heat shield is integrated into the structure of a spacecraft, and used to both carry loads and protect against high temperatures.

Problems solved by technology

The state of the art has three main problems that have prevented its use on all vehicles and engines: weight, brittleness, and manufacturability.

Large coverage with a dense material forces the heat shield to be very heavy.

These materials are also very brittle, meaning that they cannot be used to help support the loads generated by the vehicle or engine.

Last, also due to the material brittleness, manufacturing smooth shapes out of the material is difficult.

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