The aerodynamic forces for a Darrieus rotor with straight blades: Wind tunnel measurements

Pitch angle control for a small-scale Darrieus vertical axis wind turbine with straight blades (H-Type VAWT)

“…Balduzzi et al [45] validated their CFD simulation results for a VAWT against the experiment conducted in a wind tunnel with a full-scale VAWT, which is exactly the same geometry used in the CFD model. Vittecoq and Laneville [46] reported reliable experimental results in terms of instantaneous torque output of a Darrieus VAWT rotor. However, the experimental studies of a VAWT with variable blade pitch angles are quite rare in the open literature.…”

A critical analysis of the stall onset in vertical axis wind turbines

“…The aerodynamic investigations on VAWTs have confirmed that the presence of the dynamic stall phenomenon has been observed under some operating conditions and still it is not very well known except that it is being associated mainly to low tip speed ratios (TSRs). The range of TSRs where dynamic stall appears has been found to be different in each case investigated [15,16,17,18,19,20,21]. In addition, the parameter c/D, that relates the chord length and diameter, have been demonstrated to play a significant role in the development of dynamic stall on VAWTs and according to Buchner et al [22], the tip speed ratio alone is not sufficient to describe the dynamic stall phenomenon.…”

Measurement of high solidity vertical axis wind turbine aerodynamic loads under high vibration response conditions

“…Because the fatigue life of a VAWT is often considered as equally important as power output, it has a substantial impact on the cost effectiveness of a wind turbine system (Veers, 1983). As such, the current research endeavours to build upon previous experimental studies (Oler et al, 1983;Vittecoq and Laneville, 1983) to further the fundamental understanding of VAWT aerodynamic loading, and thus vibration excitation. A particular emphasis will be given to high solidity (Solidity ratio, s¼Nc/2R¼0.43), low rotational velocity (30 to 160 rpm), VAWT designs, where dynamic stall effects are dominant (Paraschivoiu, 2002).…”