Numerical Simulation of VAWT Stochastic Aerodynamic Loads Produced by Atmospheric Turbulence

Blade fatigue life is an important element in determining the economic viability of the Vertical Axis Wind Turbine (VAWT). A principal source of blade fatigue is thought to be the stochastic (i.e., random) aerodynamic loads created by atmospheric turbulence. This report describes the theoretical background of the VAWT Stochastic Aerodynamic Loads (VAWT-SAL) computer code, whose purpose is to numerically simulate these random loads, given the rotor geometry, operating conditions, and assumed turbulence properties. A Double-Multiple-StreamTube (DMST) analysis is employed to model the rotor’s aerodynamic response.