涡轮叶片内“冲击-气膜出流”局部换热特性数值模拟

Local Heat Transfer Characteristics in "Impingement-Film" Cooling Style About Inner Side of Gas Turbine Blade

用RSM模型对有、无冲击气膜出流冷气侧气膜孔局部换热特性进行了数值研究。取气膜孔前后3倍气膜孔径范围为研究对象。在无冲击射流时,通过改变来流雷诺数、气膜出流与横流密流比,对气膜孔的“溢流效应”进行了研究。研究发现,气膜孔局部的换热均随两者的增加而增强。将实验结果和计算结果进行了比较,趋势吻合。在有冲击射流时,着重研究了流动和几何参数对气膜孔局部换热特性的影响,分析了“冲击-气膜出流”局部换热特性规律。

Numerical investigation for local heat transfer characteristics of the inner side of turbine blade near film cooling holes, whether there is impingement or no has been carried out with an RSM turbulence model. The research object is focused on the area three diameter before and behind the film holes. When there is no impingement, the investigation about flow extravasation effect form film cooling holes is carried out with different cross flow Reynolds Numbers and different density flow ratios of the film outflow to cross flow. The research results indicate that the local heat transfer near the film cooling holes is enhanced with increasing cross flow Reynolds Numbers and density flow ratios of film outflow to cross flow. Experimental and computational data are compared, and their data curves fit well. When there is impingement, the effect of flow and geometrical parameters on the local heat transfer characteristics near film cooling holes is investigated, and the mechanism of local heat transfer characteristics is obtained.