Computational and experimental study of intake ground vortices

The ground vortices generated by an intake under both headwind and crosswind configurations have been investigated using computational and experimental approaches. The flow field of a scale-model intake was experimentally studied using stereoscopic particle image velocimetry to measure the ground vortex in conjunction with induct total pressure measurements for the internal flow. The computational predictions were performed using an unsteady Reynolds averaged Navier-Stokes approach. The experimental results show that under crosswind conditions a single ground vortex forms which becomes stronger as the crossflow velocity is increased. Under headwind conditions the measured ground vortex strength initially increases with freestream velocity before it reaches a local maximum and then reduces thereafter. The computations also exhibit the same characteristics and show good agreement with the measurements for some configurations. Based on the predictions, the complex flow field topology is investigated and a detailed flow model of the vortex flow field under crosswind conditions is proposed.