| Summary: | 碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 94 === It is of practical importance for the development of a numerical method for the combustion and heat-transfer analyses of afterburners, since they are characterized by the high-temperature combustion which is hard to measure. In the present study, numerical analyses of the three-dimensional conjugate heat transfer of an afterburner installed with a heat shield have been conducted. A new computational model for the conjugate flow and heat-transfer, characterized by the simultaneous solution of both flow and conduction in the solid, has been developed for the highly turbulent flow and applied to the film-cooling analysis of the heat shield with a temperature difference between both sides of the heat shield above 1000K. Numerical results obtained from the present study reveal that a higher shield temperature at outlet is predicted if the axial conduction in solid is neglected. A higher mass flow rate in the coolant flow, generated by a higher inlet velocity, makes the temperature drop of the heat shield more significant. For the best cooling effectiveness, the shield with film-cooling is batter than that without film-cooling at the same coolant inlet boundary condition. There exists an optimal slot width for the best film cooling effect. For various injection angles, the case with a horizontal slot makes the biggest temperature drop in the shield. The present model can be applied to the afterburner and ramjet analyses with high-speed turbulent combustion flow, if the conjugate heat transfer model is coupled with the spray combustion model.
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