Modified virtual blade method for propeller modelling

Abstract

The emergence of large, propeller-based aircraft has revived interest in propeller design and optimization with the use of numerical methods. The flow complexity and computational time necessary to solve complicated flow patterns trailing behind rotating blades, created a need for faster than fully resolved 3D CFD, yet comparably accurate methods for validating multiple design points in shorter time. Improved Virtual Blade Method (VBM) for 2-bladed propeller, including method implementation, analysis and validation against 3D numerical and experimental data is presented. The study introduces adjustments to the original method, accounting for differences between VBM and fully resolved numerical models. These modifications prove to increase the model accuracy for the propeller under consideration and could potentially be applied for different blade configurations as well. The modified Virtual Blade Method allows one to compute the propeller performance with comparable accuracy to 3D CFD computation using only 10% of time needed for one computational point.