An Algorithm for the Aerodynamic Analysis of Rotating Blades Using a Weak Viscous-Inviscid Interaction Method

An algorithm based on a weak viscous-inviscid interaction method is developed for the aerodynamic analysis of rotating blades under steady and incompressible flow conditions for configurations where the aerodynamics of each blade can be treated in isolation. A weak viscous-inviscid interaction method for calculating the aerodynamics of airfoil geometries, which is based on a two-dimensional source-vortex panel method and the momentum-integral method, is updated using state-of-the-art models and correlations to predict specific flow phenomena such as transitioning flow and separated flow. The blade-element-momentum theory with Prandtl root- and tip-loss corrections is used to calculate the three-dimensional aerodynamics of rotating blades, using the two-dimensional aerodynamic predictions of the viscous-inviscid interaction method and empirical stall delay models. The algorithm is shown to provide predictions that are sufficiently accurate for blade design optimization under unstalled operating conditions. The accuracy of the algorithm is limited to about 3° ∼ 5° angle of attack beyond stall.