Acceleration of vortex-particle simulations using a pseudo-particle method

Abstract

Vortex methods like vortex-lattice or vortex-panel methods are particularly promising to enhance the industrial aerodynamic design process of modern wind turbines. However, despite their advantages over low order methods, like the blade-element-momentum theory, vortex methods share an essential disadvantage. Their computational cost rapidly increases, which is due to their n-body problem characteristics. To overcome this issue, a method that neither relies on multipole expansions nor on a multi-grid approach is presented. Based on the aerodynamic simulation of the MEXICO rotor, it is shown that the proposed vortex pseudo-particle method (VPPM) is able to reduce the computational cost related to the n-body problem of vortex methods to O(n × log(n)). However, its application is not only advantageous in terms of the reduction of the computational cost. Since vortex-and pseudo-particles share the same properties, the VPPM's implementation is quite simple compared to that of fast multipole methods. Furthermore, no method specific boundary-conditions need to be imposed as in the case of multi-grid methods. Therefore, the presented pseudo-particle approach is an attractive alternative to fast multipole or multi-grid methods.