摘要
Gamma-theta转捩模型是Menter及其合作者提出的一个基于经验关系的转捩模型,其经验关系式和模型参数是通过来流米雷诺数均在150万以下的T3系列平板实验在CFX程序中标定的。首先通过T3A平板修正了转捩经验关系式,然后对S&K平板实验进行了数值模拟,研究了较高雷诺数下模型控制方程扩散项系数以及与数值扩散相关的流向网格尺度对gamma-theta模型转捩预测结果的影响。模拟的结果表明,这些因素对转捩位置都有明显影响,并且gamma方程的扩散项系数还影响转捩完成后全湍区的摩阻值。三种因素对转捩预测影响的趋势分别为:gamma方程的扩散项系数越大,theta方程的扩散项系数越小,流向网格尺度越大,则转捩位置越靠前。
Gamma- theta model is correlation based transition prediction model developed by Menter et. al. Its empirical correlation and model parameters were calibrated for CFX solver by T3 series flat plate experiments which unite Reynolds number all below 1.5 million. In present work, empirical correlation was re-calibrated by T3A plate. Then ,influence of model equation diffusion term coefficients and numeri- cal diffusion effect related to stream-wise grid scale on transition prediction was investigated experiment on S ＆ K flat plate with a unite Reynolds number of 3.34 million. Result shows by numerical that diffusion term coefficients and stream- wise grid scale all have significant effect on transition prediction. Further- more, with larger gamma- equation diffusion term, smaller theta- equation diffusion term or larger stream- wise grid scale, transition position predicted by gamma- theta model will move forward.
出处
《航空计算技术》
2013年第5期78-81,共4页
Aeronautical Computing Technique
关键词
转捩预测
网格依赖
数值扩散
经验参数
transition prediction
grid sensitivity
numerical diffusion
empirical parameter
