swirling number meaning in English

旋流数

When dealing with a low swirl number flow , the results by renormalization group ( rng ) k - ? model agree well enough with experiments , so we do not have to apply reynolds stress model ( rsm )
在计算弱旋气相流动时， rng ?模型可以满足工程上的精度需求，因而没有必要运用计算量很大的雷诺应力模型。
But when the swirl number is high , we have to resort to rsm , because of the obvious differences between experimental and numerical results by the models based on " effective viscosity "
但是，在强旋流动中，基于“有效粘性”的各个模型的计算结果和实验相差很远，只有采用雷诺应力模型才能得到较为满意的结果。