Behavior of the Blade Tip Vortices of a Wind Turbine Equipped with a Brimmed-Diffuser Shroud
Behavior of the Blade Tip Vortices of a Wind Turbine Equipped with a Brimmed-Diffuser Shroud
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DOI：
10.3390/en5125229
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发表时间：
2012-12
期刊：
影响因子：
3.2
通讯作者：
Shuhei Takahashi;Yuya Hata;Y. Ohya;T. Karasudani;T. Uchida
中科院分区：
文献类型：
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作者：
Shuhei Takahashi;Yuya Hata;Y. Ohya;T. Karasudani;T. Uchida
为了阐明配备有边缘扩散器护罩的风力涡轮机（称为“风力透镜涡轮机”）的叶尖涡流的行为，我们使用大涡模拟（LES）进行了三维数值模拟。由于这种独特的涡轮机不仅包括旋转叶片，而且还包括在出口边缘处具有宽环边缘的扩压器护罩，因此涡轮机周围的流场是高度复杂和不稳定的。以前，我们的研究小组使用致动器圆盘近似进行了数值模拟，其中旋转叶片被简单地建模为流体上的外力。因此，无法模拟旋转叶片和围带周围的详细流型，包括叶尖涡流。在本CFD模拟中，我们使用移动边界技术来模拟旋转叶片周围的流动，而不是致动器盘近似，以便特别关注叶尖涡流。计算结果表明，在叶尖与扩压器内表面之间形成了一对由叶尖涡和反向旋转涡组成的涡系。由于这些涡相互作用，叶尖涡被反向旋转的涡削弱。结果表明，与过去的风洞实验吻合良好。
To clarify the behavior of the blade tip vortices of a wind turbine equipped with a brimmed-diffuser shroud, called a “Wind-Lens turbine”, we conducted a three-dimensional numerical simulation using a large eddy simulation (LES). Since this unique wind turbine consists of not only rotating blades but also a diffuser shroud with a broad-ring brim at the exit periphery, the flow field around the turbine is highly complex and unsteady. Previously, our research group conducted numerical simulations using an actuator-disc approximation, in which the rotating blades were simply modeled as an external force on the fluid. Therefore, the detailed flow patterns around the rotating blades and the shroud, including the blade tip vortices, could not be simulated. Instead of an actuator-disc approximation, we used a moving boundary technique in the present CFD simulation to simulate the flow around a rotating blade in order to focus especially on blade tip vortices. The simulation results showed a pair of vortices consisting of a blade tip vortex and a counter-rotating vortex which was generated between the blade tip and the inner surface of the diffuser. Since these vortices interacted with each other, the blade tip vortex was weakened by the counter-rotating vortex. The results showed good agreement with past wind tunnel experiments.