Numerical model for rapid computatuon of the flow-field of a rotor in hover

In the present article, the authors are performing a comparison study between two vortex models for the rapid numerical computation of the static thrust of a helicopter rotor in hover. The aim of this study is to access the rapidity and accuracy of a vortex model, comprised of a series of vortex rings and a single semi-infinite vortex cylinder, compared to a helical wake model with straight-line segmentation. Studies are performed for the optimal number of vortex elements, as well as for their optimal positioning, in order to provide both fast computation and good agreement with the experimental data obtained from a wind tunnel test of a model rotor. The studied vortex model is shown to significantly reduce the amount of computational time required to evaluate the performance of the model rotor, when compared to the helical wake model, while offering a similar degree of accuracy.