基于实密度的卧式浪流轮机水槽实验研究分析

实密度是影响轮机获能特性的关键因素之一。文中以卧式轮机实密度为基变量,以其获能系数为主要考察点,对3种实密度卧式轮机进行水槽实验方案设计和水动力性能研究。实验分别对水流流速、轮机旋转角速度、主轴转矩以及功率进行测量,并对其对主轴的扭矩、轮机的获能系数以及叶片的旋转特性进行定量分析,最终证实了该卧式轮机的单一运行特性。通过绘制基于实密度的轮机转矩—转角曲线、获能系数—尖速比曲线和轮机功率—尖速比曲线,阐明了实密度影响卧式轮机获能水动力性能的规律,即其获能系数和发电功率都随着工况速比呈先增后降趋势。实密度较低轮机因浪流流失而获得能量小,但实密度过高轮机会导致叶片间湍流涌动,加速叶片失速特性而影响轮机获能。这为卧式浪流轮机结构优化提供了可靠依据和借鉴。

A Sink Experimental Investigation on the Horizontal Wave-Flow Turbine Based on Blade Solidities

Blade solidity is one of the key factors affecting the hydrodynamic performance of a turbine. In order to understand the relationships between the blade solidity and the power coefficient (Cp) of the novel wave and tide turbine, a sink experiment was designed and conducted for its hydrodynamic analysis by using 3 different blade solidities as the experimental based variables, with the power coefficient (Cp) as the experimental target. The sink experiment measured the flow velocity, turbine rotation angular velocity, principal axis torque and power, and carried out quantitative analysis on the influence on the principal torsion, power coefficient (Cp) and blade rotating characteristics. Through comparative analysis, it confirmed the characteristics of single rotation direction of this type of turbine. By drawing the curves of torque-angle, Cp-TRS and power-TRS based on blade solidity, it expounded the rule of influence of blade solidities on the hydrodynamic performance of this turbine. The rule shows that the power coefficient (Cp) and generation power increase first and then decrease with the change of working condition speed ratio. The turbine with relatively lower blade solidity obtains less energy due to wave-flow loss, while that with high blade solidity leads to turbulent flows among blades, thus affecting its energy capture owing to accelerating blade stalling characteristics. Finally, this paper provides reliable references for the structural optimization of the horizontal wave-flow turbine.