潮流能导管水轮机水动力性能研究

为了提高潮流能水轮机发电装置的输出功率，采用雷诺平均法（RANS-CFD）从功率、载荷、空化特性、非定常特性及多导管的影响等方面，对一种新型水平轴导管水轮机进行了理论研究，并通过拖拽水池试验对计算结果进行了验证。研究结果表明：导管水轮机相比裸水轮机具有较高的输出功率及轴向推力，在来流角±30°内仍能保持较高的输出功率。并且导管水轮机在设计工况下有很好的非空化特性及非定常特性。对于多导管组水轮机而言，附属大导管组能在全尖速比范围内进一步提升水轮机的功率及轴向推力，且随着附属导管攻角的增大，功率及轴向推力也将进一步增大。而附属小导管组则不利于水轮机的功率提升。研究成果对导管水轮机发电装置的优化设计起到支撑作用。

Hydrodynamic performance of tidal current ducted turbines

To improve the power output of a tidal energy conversion turbine system, a new type of horizontal axis ducted turbines is studied using a Reynolds Averaged Navier Stokes (RANS)-CFD method, focusing on modeling power output, load, cavitation, flow unsteadiness, and the effect of attached ducts. A towing tank experiment is carried out to validate the numerical simulations. The results show that a ducted turbine has higher power output and larger axial thrust than those of the bare turbine and can maintain high power output within ±30° of the yaw angle. And it is featured with non-cavitation and satisfactory flow unsteadiness under design conditions. For a multi-ducted turbine, large attached ducts can improve its power and thrust in the full range of tip-to-speed ratio and further improvement can be achieved if the angles of attack of the ducts are increased, while small duct sizes are not conducive to the power output. Thus, this study demonstrates the advantages of the ducted turbine and its broad prospect of engineering application.