Transpiration Cooling Control And Numerical Simulation In Porous Media

Transpiration cooling in porous media is a high effective method to turn down the temperature of workpiece which works at high temperature condition (such as the surface of rocket, missile, airship and other high-speed aircraft). To defend the surface of the workpiece from burn down, and to make the workpiece could work longer, but not change it's shape, it is necessarily to adopt the method of transpiration cooling in porous media. Therefore, with the development of global industry, the technique of transpiration cooling in porous media arrest more and more people's attention.The structure inside the porous material is very complex, and it's the most important factor of the complicated flow, heat and mass transfer in porous media. Not only the turbulent is considered during the study, but also considered heat and mass transfer even chemic reaction. Complicated inside structure cause the inter resistance asymmetrical. Therefore, it's very hard to research the law of flow, heat and mass transfer inside the porous material. Presently, most research of transpire cooling in porous media aimed at the breakage that refrigerant to borderland of high temperature fluid and the slack effect of the convection. Research in heat and mass transfer and temperature distribution inside the porous media is rarely. The totally description of transpiration cooling in porous media should consist of fluid and heat exchange both inside porous media and in mainstream area.In this dissertation, the main job is to research the law of heat exchange inside the porous media. Because of the complicacy and the abnormity of the structure inside porous media, it's hardly to research the law of heat exchange. So it's necessarily to do something to predigest the model. We assumed that the porous material is well-proportioned first, then we reason out the energy control equation of heat exchange between fluid and material inside the porous with no chemic reaction and imcompress refrigerant. After that a computational fluid dynamics code was used to simulate the two-dimensional steady flow and heat exchange in the porous media. Both the condition of different porosity and different mass flux were simulated in this dissertation. To recognize the law of transpiration cooling in porous media clearly, the result of the simulation was analyzed at last. The effective simulation result also can be used as reference for the actual application of transpiration cooling in porous media.