Y. Takamatsu et al., EXPERIMENTAL CONSIDERATIONS IN AN APPROXIMATE METHOD FOR ESTIMATING THE BLADE PERFORMANCE OF DARRIEUS-TYPE CROSS-FLOW WATER TURBINES, JSME international journal. Series B, fluids and thermal engineering, 36(1), 1993, pp. 135-142
To estimate the blade performance of a Darrieus-type cross-flow water
turbine, differences between the characteristics of a Darrieus blade w
hich moves along a circular path and that of a blade at rest in a unif
orm steady flow are examined quantitatively through the use of experim
ental data for three types of blades with different cambers or chord l
engths. It is found that a unique stall character strongly affects the
drag force acting on the Darrieus blade. A model of the changing patt
ern of the drag coefficient due to dynamic stall is proposed from the
results of measurement for estimating the blade characteristics. As a
result, the blade characteristics and performance of the Darrieus-type
runner are predicted well by the use of aerofoil data in a uniform st
eady flow, taking into account the effect of a circling motion and the
dynamic effect of the unsteady flow around the Darrieus blade.