Double multiple streamtube model for variable pitch vertical axis wind turbines

Abstract

An analytical model based on the double multiple streamtube method is proposed for calculating the rotor performance and aerodynamic blade forces for vertical axis wind turbines (VAWTs) with variable pitch straight blades. An interception method is utilized to determine induction factors which can be used to calculate local blade forces. The model makes allowance for flow expansion, flow curvature, tip loss and dynamic stall. Aerodynamic prediction output from this model is compared with experimental data available in the public domain for validation purposes.