Adaptive Grid Sequencing and Interpolation Schemes for Accelerated Rotor Free-Wake Analyses

Numerical acceleration schemes have been developed to improve the computational efficiency of rotor free-wake analyses. Two general methodologies were formulated: an adaptive grid sequencing scheme, and a velocity field interpolation scheme. Both approaches reduce considerably the number of induced velocity evaluations in the free-wake scheme, but without significant loss in predictive accuracy. The methods have been implemented and evaluated for the Maryland Free-Wake (MFW) Analysis, which is based on a pseudo-implicit, predictor-corrector relaxation algorithm. The acceleration schemes were found to produce up to an order of magnitude decrease in execution time. Both methods are generic in formulation and application, and may be adapted for use in other free-wake methodologies. A third method, which specifically exploits the pseudo-implicitness of the MFW, has also been implemented. This method results in further increases in computational efficiency.