Then basing on the free-vortexequation, potential equation and stream function of flow are achieved by mathematical analyze, and solving these equations gives flow fields.
从自由涡运动方程出发，推导出管内流场的势函数和流函数方程，获得了管内流场的数学分析解；
2
The vorticity equation was first established and the characteristics of vortex motion in two-dimensional shallow-water flows was analyzed, and then discrete vortex method (DVM) was briefly described.
Combining momentum theory and vortex theory, rotor circulation equation was deduced. The rotor down-wash flow field was calculated using generalized down-wash flow model.