复杂边界条件下的多层多孔壁温度场的计算模型

CALCULATING MODEL FOR TEMPERATURE FIELD OF MULTI LAYER AND MULTI HOLE WALL UNDER COMPLEX BOUNDARY CONDITIONS

经过推导给出了具有孔内和内外表面对流换热及外表面热辐射复杂边界条件下的多层多孔壁温度场的计算模型，并以具有陶瓷隔热涂层的全气膜覆盖气冷叶片为例进行了温度场计算。计算结果表明：陶瓷涂层具有明显的隔热效果，并可明显地减小冷却空气用量；燃气温度对壁温影响较大；考虑热辐射将更加符合实际物理过程；对于涡轮叶片若不考虑热辐射将低估壁温 １．５％ ～３．５％ 。该模型可用于多层多孔壁冷却结构形式的发动机高温部件的优化设计。

This paper provides a calculating model for the temperature field of a multi layer and multi hole wall with complex boundary conditions. The factors, such as convective heat transfer on the inner and outer surfaces, convective heat transfer within the small holes and thermal radiation from combustion gas to the outer surface, are considered. As an example, the temperature field of a full coverage film cooled turbine vane with ceramic coating is calculated. The calculated results show that: (a) ceramic coating has obvious effect of heat insulation and can reduce coolant air flow significantly; (b) the temperature of combustion gas has a large effect on wall temperature; (c) considering thermal radiation will more closely fit the practical physical process; (d) the wall temperature may be underestimated 1.5%～3.5% to turbine vane without considering thermal radiation. The model of this paper could be used for optimum design of high temperature components of engines with the cooling construction of multi layer and multi hole walls.