In-Situ Ablation and Thermal Sensing of a 3-Dimensionally Woven Carbon/Phenolic Composite for Computer Modeling and Simulation

摘要

Koo Research Group conducted an investigation to characterize the ablation behavior of an innovative ablative material provided by Airbus Safran Launchers. Ablation is a complex thermochemical process that is most simply described as erosion due to high-speed, high-temperature environments, such as those experienced by the nozzles of solid rocket motors (SRM) and by the leading edges of hypersonic vehicles. The material used in this investigation was a 3-dimensionally (3D) woven carbon/phenolic material in use on solid rocket motor nozzle cowl and aft portion of exit cones. These tests exposed material samples to heat fluxes of 350 W/cm~2 and 1,000 W/cm~2 which respectively are representing thermal fluxes commonly calculated in nozzle cowl or exit cones and leading edges of hypersonic vehicles. This test program generated data from two optical imaging techniques, previously unused by this research group, in addition to the group's proprietary In-Situ Ablation Sensor and an infrared laser pyrometer. In the first series of tests (heat flux of 350 W/cm~2), no material surface regression was measured as it is observed on the SRM nozzle parts where this material is used. Under heat flux of 1,000 W/cm~2, the material showed behavior in conformity with the ablative performance-versus-density law. In this paper, results of tests where samples were exposed to a heat flux of 1,000 W/cm~2 are presented and discussed.