Design And Analysis Of Graphite Foam Infiltrated With High Temperature Phase Change Energy Strorage Composite

Thermal protection technology is one of the most important basical research projects of aircraft flight safety. These thesis designs a "hot structure-phase change heat sink—heat insulation" compound thermal protection system for a planetary probe: the outside surface is C/C shell hot structure, the middle layer utilize a graphite foam infiltrated with NaCl energy strorage composite as the heat sink, a flexible insulation blanket is used for thermal insulation purpose in inner side.Employing the soft template method, taking the mesophase pitch as the carbon source and polyurethane foam as template,via processes such as suspension preparation?impregnation and drying?template replication?oxidative stabilization?carbonization and graphitization, the graphite foam is prepared. For each preparation process of the graphite foam, a series tests of density?micro morphology?infrared spectrum?elements content?XRD and Raman spectrum are taken. The ultimate density is 0.43g/cm3, graphite degree is 42%, thermal conductivity is 7.8 W/(m·K) and compressive strength is 7.40MPa.NaCl is selected as the high temperature phase change material, the energy strorage composite is prepared in immersion method, its phase change temperature is 793?, phase change enthalpy is 420.4J/g, the thermal conductivity is 12.92 W/(m-K). NaCl has full filled the pores on the outer surface and there is no new phase or element is produced in impregnation process.The heat transfer process of the compound phase change thermal protection system is designed and analyzed utilize FLUENT. Comparison indicate that the 3-10-8 thermal protection precept could satisfy the design requirements,and its mass is minimum.Comparing with the precept of C/C fins enhanced LiF heat transfer, this paper possesses a considerable weight reduction effect.