Evaluation of Cooling Performance by Rocket Combustor of C/C Composite andC/C-SiC Composite Cooled Structures Using Metallic Cooling Tubes

摘要

In this study, the cooling performance of a carbon/carbon (C/C) composite structure and a silicon-infiltrated C/C (C/C-SiC) composite structurewith metallic cooling tubes that are fixed by an elastic force without chemical bonding in a rocket combustor was evaluated experimentally using combustion gas. Gaseous hydrogen was used as a fuel and gaseous oxygen was used as an oxidizer in the heating test. The temperature of the surfaces of these composites was maintained below 1500 K when the temperature of thecombustion gas was approximately 2800 K and the heat flux to the combustion chamber wall was approximately 9 MW/m2. The stainless steel tubes that were in contact with the composite structure were not thermally damaged after the heating test. Results of the heating test showed that such a metallic tube-cooled composite structure could be used as a cooling structure (also as a heat exchanger) to control the surface temperature of the composites. It is important to cool the surface of the composite structure to 1800 K or less, because the life of a ceramic coating that is used to protect the surface can be increased. Therefore, it is expected that these metallic tube-cooled C/C composite and C/C-SiC composite structures can be applied to reusable engines such as a rocket-ramjet combined-cycle engine.