Conjugate heat transfer analysis is carried out in a cascade domain for a nozzle guide vane. The nozzle guide vane is internally cooled by jet impingement cooling, and the external surface is cooled by film cooling. A computational study was carried out with three different materials, having conductivity values of 0.0048, 0.2 and 1.1 W/m.K. Distribution of local surface temperature along the leading edge, pressure and suction surface is reported. The leading edge region showed the maximum increase in internal surface temperature as the conductivity increased among the different regions of the vane internal surface. However, the pressure and suction surfaces showed relatively less increase in the surface temperature distribution. In order to validate the computational result, the obtained temperature data were compared with experimentally obtained surface temperature data. The flow phenomena like jet lift-off and self-induced cross-flow affect the local temperature distribution differently in the three materials. For a constant mainstream and coolant flow, the surface temperature gradient is higher for the lower conductivity material, and the gradient decreases as conductivity increases. Hence, a material with higher conductivity is desired in a combined impingement and film cooled nozzle guide vane, to increase the durability of the vane.

中文翻译：

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导热系数对喷嘴导叶内表面温度分布的影响

共轭传热分析是在喷嘴导叶的级联域中进行的。喷嘴导向叶片通过射流冷却在内部进行冷却，外表面通过薄膜冷却进行冷却。用三种不同的材料进行了计算研究，电导率值分别为0.0048、0.2和1.1 W / mK，报告了沿前缘，压力和吸力面的局部表面温度分布。当叶片内表面的不同区域之间的电导率增加时，前缘区域显示出内表面温度的最大增加。然而，压力表面和吸力表面显示出相对较小的表面温度分布增加。为了验证计算结果，将获得的温度数据与实验获得的表面温度数据进行比较。射流剥离和自感应横流等流动现象在三种材料中对局部温度分布的影响不同。对于恒定的主流和冷却剂流量，电导率较低的材料的表面温度梯度较高，并且随着电导率的增加，梯度减小。因此，在冲击和薄膜冷却的喷嘴导向叶片的组合中需要具有更高电导率的材料，以增加叶片的耐用性。对于较低电导率的材料，表面温度梯度较高，并且随着电导率的增加，梯度减小。因此，在冲击和薄膜冷却的喷嘴导向叶片的组合中需要具有更高电导率的材料，以增加叶片的耐用性。对于较低电导率的材料，表面温度梯度较高，并且随着电导率的增加，梯度减小。因此，在冲击和薄膜冷却的喷嘴导向叶片的组合中需要具有更高电导率的材料，以增加叶片的耐用性。