Wind-Tunnel Simulation of the Wake of a Large Wind Turbine in a Stable Boundary Layer. Part 1: The Boundary-Layer Simulation
Wind-Tunnel Simulation of the Wake of a Large Wind Turbine in a Stable Boundary Layer. Part 1: The Boundary-Layer Simulation
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稳定边界层中大型风力发电机尾流的风洞模拟。
DOI：
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发表时间：
2014
影响因子：
4.3
通讯作者：
F. Pascheke
中科院分区：
文献类型：
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作者：
P. Hancock;F. Pascheke
在EnFlo分层流风洞中，作为海上环境中风力涡轮机尾流研究的一部分，已在中性和稳定边界层中进行了测量。工作段足够长，使流动几乎不随流向距离变化。为了系统化，中性和稳定条件下，Irwin型螺旋的流剖面发生器和表面粗糙度相同。通过调整流量发生器来实现所需的剖面，即使对于中性流，也是一种高度迭代的技术，并且目前的结果表明，对于稳定流（以及需要满足的更多条件），其迭代性不会降低，因此在本研究中没有尝试。稳定的情况下流符合在大多数方面的莫宁-奥布霍夫相似的表面层。在工作段入口处应用线性温度分布，导致边界层上方的发展流中的近线性分布和“强”强加稳定性，而表面处的条件是“弱”的。即使粗糙雷诺数$${<}1$$<1，气动粗糙度长度（平均速度）也不受稳定性的影响，而热粗糙度长度要小得多，这是可以预料的。中性的情况下，是哈罗德数无关，并通过推理，稳定的情况下，也是哈罗德数无关。
Measurements have been made in both a neutral and a stable boundary layer as part of an investigation of the wakes of wind turbines in an offshore environment, in the EnFlo stratified flow wind tunnel. The working section is long enough for the flow to have become very nearly invariant with streamwise distance. In order to be systematic, the flow profile generators of Irwin-type spires and surface roughness were the same for both neutral and stable conditions. Achieving the required profiles by adjusting the flow generators, even for neutral flow, is a highly iterative art, and the present results indicate that it will be no less iterative for a stable flow (as well as there being more conditions to meet), so this was not attempted in the present investigation. The stable-case flow conformed in most respects to Monin–Obukhov similarity in the surface layer. A linear temperature profile was applied at the working section inlet, resulting in a near-linear profile in the developed flow above the boundary layer and ‘strong’ imposed stability, while the condition at the surface was ‘weak’. Aerodynamic roughness length (mean velocity) was not affected by stability even though the roughness Reynolds number $${<}1$$<1, while the thermal roughness length was much smaller, as is to be expected. The neutral case was Reynolds-number independent, and by inference, the stable case was also Reynolds-number independent.