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论文类型：期刊论文

发表时间：2013-04-01

发表刊物：JOURNAL OF HYDRODYNAMICS

收录刊物：SCIE、EI

卷号：25

期号：2

页面范围：280-287

ISSN号：1001-6058

关键字：tidal-current turbine; preset angle of attack; tidal energy; numerical simulation

摘要：The instantaneous angle of attack on the blade has a significant effect on the hydrodynamic performance of a vertical-axis tidal-current turbine with straight blades. This paper investigates the influence of different preset angles of attack on the hydrodynamic performance of a three-bladed, vertical-axis, tidal-current turbine both experimentally and numerically. Experiments are carried out in a towing tank. This tested turbine's solidity is 0.1146. The preset angles of attack on the blade are -3 degrees, 0 degrees, 3 degrees, and 5 degrees, in the experiments. Experimental results show that with the increase of the preset angle of attack from -3 degrees, to 5 degrees, the hydrodynamic performance of the turbine is improved significantly with the power coefficients being increased from 15.3% to 34.8%, respectively. Compared to the result of a 0 degrees preset angle of attack, the performance of the turbine with positive preset angles of attack is experimentally demonstrated to be beneficial. This performance improvement is also shown by numerical simulations based on the Unsteady Reynolds Averaged Navier-Stokes (URANS) equations. In addition, the numerical results show that the optimal positive preset angle of attack is 7 degrees for the turbine studied. The corresponding power coefficient is 38%. Beyond this optimal preset angle of attack, the hydrodynamic performance of the turbine decreases. Therefore, due to the dynamic stall phenomenon, an optimal preset angle of attack exists for any vertical-axis turbine. This value should be considered in the design of a vertical-axis tidal-current turbine.