水平轴潮流能水轮机数值模拟方法对比分析

Comparative Analysis on the Numerical Simulation Methods for Horizontal Axis Tidal Current Turbines

叶素动量理论和CFD方法是水平轴潮流能水轮机性能分析中运用较为广泛的数值模拟方法,文中结合小尺寸水轮机模型试验,对比分析了叶素动量理论和CFD方法在水轮机性能分析中的准确性和适用性。验证结果表明:叶素动量理论和CFD方法均能对水轮机的性能进行预报,且CFD精度高于动量叶素理论;大尖速比时,动量叶素理论偏离较高,不再适合性能预报;在小尖速比下,建议采用RNG k-ε模型的CFD方法进行分析计算;动量叶素理论适合设计初期设计方案的对比分析,而CFD方法适合对设计结果的验证校核和详细分析。

This paper conducts a comparative analysis on the accuracy and applicability of the blade element momentum（BEM） theory and computational fluid dynamics（CFD） method, the two most widely used numerical simulation methods for hydrodynamic performance analysis of horizontal axis tidal current turbine. To verify the computational results, an open water test is carried out in a towing tank with a self-designed turbine. The results show that both the two methods can provide a satisfactory prediction for the experimental turbine performance,and a higher accuracy is acquired with CFD. With increasing tip speed ratio（TSR）, higher deviation is observed with the BEM theory, not applicable for prediction anymore. For low TSR, in contrast, it is suggested that the CFD method of the RNG model be adopted for analysis and calculation. Furthermore, the use of BEM is suited to the comparative analysis of the design scheme under early stage, while CFD is for post-design validation and indepth analysis.