An investigation of flow fields around flanged diffusers using CFD
An investigation of flow fields around flanged diffusers using CFD
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DOI：
10.1016/j.jweia.2003.12.003
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发表时间：
2004-03-01
影响因子：
4.8
通讯作者：
Ohya, Y
中科院分区：
文献类型：
--
作者：
Abe, K;Ohya, Y
为研制1.5 kW以下的小型风力机，对法兰扩压器周围的流场进行了数值研究。在计算中，在非线性涡流-黏度模型的框架内，采用了一种先进的闭合近似，专门用于改进湍流各向异性的表示。计算结果与相应的实验数据的比较表明，本文的计算能够对当前复杂湍流流场提供合理的预测。在此基础上，通过对计算结果的处理，估算了不同扩散器开口角和载荷系数条件下的输入功率系数。结果表明，加载系数和开口角对扩压器内部分离的性质有很大的影响，因此扩压器的性能在很大程度上取决于开口角。目前的研究表明，翼缘扩压器的最佳性能载荷系数要比裸风力机的载荷系数小得多。(C) 2003 Elsevier Ltd.版权所有。
Numerical investigations are carried out for flow fields around flanged diffusers to develop small-type wind turbines under 1.5 kW. In the calculations, an advanced closure approximation is adopted, within the framework of non-linear eddy-viscosity modeling, which aims specifically at an improved representation of turbulence anisotropy. Comparison of the computed results with the corresponding experimental data shows that the present calculation has the capability of providing reasonable predictions for the present complex turbulent flows. Furthermore, by processing the computational results, the input-power coefficient is estimated under various conditions of diffuser opening angle and loading coefficient. It is shown that the performance of a flanged diffuser strongly depends on the loading coefficient as well as the opening angle because it greatly affects the nature of the separation appearing inside the diffuser. The present investigation suggests that the loading coefficient for the best performance of a flanged diffuser is considerably smaller than that for a bare wind turbine. (C) 2003 Elsevier Ltd. All rights reserved.