The Research On Modeling And Simulation Of Flow Field And Safety Spacing For Wake Vortex

Based on the concept of dynamic wake vortex spacing and foreign studies before, in this paper, the preferable models for wake vortex producing, decaying, movement are constructed to simulate the flow field of wake vortex induced by leading aircraft. And also the models for encountering and safety spacing are also constructed to simulate and analyse the safety spacing for aircraft paires.In the aspects of wake vortex decaing and movement, the field of wake vortex is divided by two parts in this paper, including the far field vortex and near field vortex. A near filed wake vortex model for decaying and movement is purposed to describe the coming into being of the wake vortex. In the near ground phases, the methord of imaging vortex is used to consider the ground effect for the forming, decaying and movement of wake voerx together. The influence of ground effect is estimited preferably by the amount of increasing lateral separation between the two inducing vortexs. In the aspect of safety spacing, the stall speed is proposed to calculate the ultimate bank angle for encounting the wake vortex, and then the maxmun acceptable bank angle can be determined by the safety factors dynamicly instead of the constant acceptable bank angle used before. Finaly, based on the calculating and simulating software, the influence factors, such as the turbulence, the stratification parameter, the density of atmosphere, the type parameters, the weight, the ground speed and the height for leading aircraft, the weight, the ground speed and the height for following aircraft, the resposing time fro pilots and so on, are all calculated and analysed separately for the forming, decaying, movement, encountering of the wake vortex and the dynamic safety spacing for wake vortex. Those factors should be taken into count together to cauculate the safety spacing.