Simplified Approach to Predicting Rough Surface Transition
Simplified Approach to Predicting Rough Surface Transition
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DOI：
10.1115/1.3072521
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发表时间：
2009-10
影响因子：
1.7
通讯作者：
R. Boyle;M. Stripf
中科院分区：
文献类型：
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作者：
R. Boyle;M. Stripf
涡轮机叶片传热预测光滑和粗糙叶片的实验数据表明，随着表面粗糙度物理高度的增加，过渡向前移动的叶片。与光滑的叶片传热一致，随着雷诺数的增加，对于固定的粗糙度高度，过渡向前移动。比较发表的实验数据。一些数据是一个规则的粗糙度几何形状的粗糙度高度，雷诺数和进口湍流强度的范围。本分析中采用的方法是从统计学意义上处理粗糙度，与暴露于实际发动机环境后测量的叶片所获得的结果一致。给出了一种由规则几何统计量确定等效砂粒粗糙度的方法。这种方法是由实验数据指导的。粗糙度过渡标准的开发，并与实验数据在整个范围内的实验测试条件进行比较。额外的比较与实验的传热数据，其中的粗糙度的几何形状是经常和统计。利用所发展的分析，在假设的发动机条件下，对高压涡轮机的第二级叶片进行了传热计算。
Turbine vane heat transfer predictions are given for smooth and rough vanes where the experimental data show transition moving forward on the vane as the surface roughness physical height increases. Consistent with smooth vane heat transfer, the transition moves forward for a fixed roughness height as the Reynolds number increases. Comparisons are presented with published experimental data. Some of the data are for a regular roughness geometry with a range of roughness heights, Reynolds numbers, and inlet turbulence intensities. The approach taken in this analysis is to treat the roughness in a statistical sense, consistent with what would be obtained from blades measured after exposure to actual engine environments. An approach is given to determine the equivalent sand grain roughness from the statistics of the regular geometry. This approach is guided by the experimental data. A roughness transition criterion is developed, and comparisons are made with experimental data over the entire range of experimental test conditions. Additional comparisons are made with experimental heat transfer data, where the roughness geometries are both regular and statistical. Using the developed analysis, heat transfer calculations are presented for the second stage vane of a high pressure turbine at hypothetical engine conditions.