The vortex wake and its induced velocity of a helicopter rotor operating near the ground at low forward speeds have been studied using a simplified free wake-groundvortex model.
Image method ideal vortex model is used for the analysis of how ground effect impacts wingtip vortex and airflow downwash angle.
采用镜像法理想涡模型分析了地面效应对翼尖涡位置和气流下洗角的影响；
3
The large eddy simulation methods can be used to analysis and calculate the decay and transport rules of wake vortex in near ground phases, but it′s too complex and difficult to use.