Fast multipole accelerated unsteady vortex lattice method based computations

Abstract

The authors present an accelerated aerodynamic computational model derived from the integration of the fast multipole method (FMM) with the unsteady vortex lattice method (UVLM) based aerodynamic model. It is determined that the performance of this computational model depends on the tuning of some FMM parameters and that there is a tradeoff between the computational speed and the accuracy of the computed loads. This tradeoff is examined by varying the truncation number, the order of the Gauss-Legendre quadrature, and the clustering parameter for the wake velocity calculations. Results of the computational cost reduction study achieved through the accelerated aerodynamic simulator are reported for a planar, rectangular lifting surface with a high aspect ratio. The computational approach presented in this paper is the first in the literature wherein the FMM has been implemented for an UVLM-based nonlinear, unsteady aerodynamic simulator. The approach has broad applicability for the study of aerodynamic and aeroelastic responses of aircraft systems and related decision support systems in dynamic data-driven application systems.