後燃器具有高溫燃燒特性，以數值模擬方法來分析其燃燒及熱傳特性具有其吸引力及必要性，是一值得研發的課題。因此，本研究以數值方法模擬分析後燃器含隔熱罩之共軛熱傳現象，並探討薄膜冷卻對隔熱罩溫度之影響。為分析後燃器含隔熱罩內外流道之流場及其與隔熱罩固體間之熱傳現象，本研究新發展一計算模式，利用紊流場在計算邊界區域所使用的邊牆函數，可以同時求解高速紊流場和固體之間的共軛熱傳問題，並成功的模擬出高低溫差達1000K以上的流場以及夾在其中的固體溫度分布。模擬結果則顯示，忽略軸向熱傳將會使隔熱罩出口端溫較高，而較高之冷卻流道入口速度，可提供較高之冷卻質量流率，並帶走較多之熱量，因而可降低隔熱罩之溫度，以效率的觀點來看，相同的冷卻流道入口邊界條件，有薄膜冷卻的散熱效率會比沒有薄膜冷卻來的高，而冷卻細縫大小的改變也會影響冷卻效率，在相同冷卻流道入口條件下，存在一最佳比例，這個比例會隨著冷卻流道流量改變，在冷卻細縫構造方面，藉由三種不同的排列方式使冷卻流體能以不同角度注入主流道，結果顯示，和軸向呈水平角度注入主流道為最佳方式。這個共軛熱傳分析方法，若結合噴霧燃燒模式，將可以應用至含隔熱罩之後燃器或衝壓引擎燃燒室高速紊流燃燒流場之模擬分析。

　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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