说明：  如何UDF计算轴向，切向，径向的速度分量 计算内部面上的质量流量及最大温度 计算每次喷射的平均路径长度 非定常求解器的自动迭代
(How to calculate UDF axial, tangential and radial component of the calculation speed of the internal surface of the mass flow rate and maximum temperature calculated for each injection, the average path length of unsteady automatic iterative solver)