FLUENT中边界条件中湍流强度怎么设置：入口边界条件中的湍流强度和出口边界条件中的回流湍流强度怎么设置？是取默认值10%吗？

经典问题,这个要根据实验数据和经验以下作为参考:Low (Intensity = 1%)Medium (Intensity = 5%)High (Intensity = 10%)You should set reasonable values of either the turbulence intensity, or k and e at an inlet boundary. Several options exist for the specification of turbulence quantities at inlets. However, unless you have absolutely no idea of the turbulence levels in your simulation (in which case, you can use the Medium (Intensity = 5%) option), you should use well chosen values of turbulence intensities and length scales.Nominal turbulence intensities range from 1% to 5% but will depend on your specific application. The default turbulence intensity value of 0.037 (that is, 3.7%) is sufficient for nominal turbulence through a circular inlet, and is a good estimate in the absence of experimental data. The allowable range of turbulence intensity specification for an inlet boundary is from 0.001 to 0.1 (that is, 0.1% to 10%), corresponding to very low and very high levels of turbulence in the flow, respectively.For external flows, such as flow over an aerofoil, relationships based on the geometric scale of the inlet boundary may not be appropriate. Therefore, you should consider using a length scale that is based on the size of the object over which flow is moving.