Comparison of different ways for VAWT aerodynamic control

Abstract Data on systematic investigations of different ways for aerodynamic control or brake of vertical axis wind turbines (VAWTs) are presented. There has been undertaken a study of the influence of various factors on VAWT aerodynamics, namely blade sweep, tilt and incidence angles as well as action of extended flaps placed on the tips of the blades or on the struts. VAWT models having wide variations of the above mentioned blade angles as well as different positions and dimensions of blade or strut extended flaps were tested in the T-2 wind tunnel in TsAGI. A VAWT with flow jets blown out of blades was investigated too. The description of a system for flow blowing and aerodynamic data obtained are presented. The relationship between VAWT power factor and the jet momentum was determined and the possibility of effective control of VAWT aerodynamics was shown. All investigated means of control are analysed and compared from the point of view of their effectiveness and possibility for using as aerodynamic brakes.