发表机构
Lakehead University; Department of Mechanical and Mechatronics Engineering, Lakehead University（湖首大学; 湖首大学机械与机电工程系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出一种计算高效的展向周期性三维大涡模拟框架，用于分析自启动垂直轴风力机的涡动力学，揭示死区与快速加速阶段的流动差异，并支持参数化研究。
AI 中文摘要
垂直轴风力机的自启动行为强烈受到沿展向发展的涡结构的影响。然而，对这一过程进行完全耦合的高保真三维分析需要大量的计算资源。本研究在OpenFOAM中提出了一种计算高效、展向周期性的三维大涡模拟框架。转子的运动通过两个逻辑函数的组合来规定，以重现垂直轴风力机自启动过程中的角速度演化。结果表明，边界层分离以及随后分离剪切层的卷起产生了脱落的涡结构，这些涡结构以有限的展向段形式对流进入尾流。这些结构沿展向的变形随展向范围的增大而增加。死区（dead-band）的特征是持续的尾流干扰和微弱的净加速度，而快速加速阶段则表现出更大的流动附着，分离局限于叶片附近较小的区域。在准稳态运行期间，涡向尾流的脱落变得可重复，下游叶片-涡相互作用减少。基于转子规定运动的方法能够实现计算高效、展向分辨的涡演化研究，适用于参数化研究和流动控制装置的评估。
英文摘要
The self-starting behavior of vertical-axis wind turbines is strongly influenced by the development of vortical structures along the span. However, a fully coupled high-fidelity three-dimensional analysis of this process requires substantial computational resources. This study presents a computationally efficient, spanwise-periodic, three-dimensional large-eddy simulation framework in OpenFOAM. The motion of the rotor is prescribed using a combination of two logistic functions to reproduce the angular-velocity evolution of a vertical-axis wind turbine undergoing self-starting. The results show that boundary-layer separation and the subsequent roll-up of the separated shear layer generate detached vortical structures that convect into the wake as finite spanwise segments. The deformation of these structures along the span increases with increasing spanwise extent. The dead-band is characterized by sustained wake interference and weak net acceleration, whereas the rapid-acceleration stage exhibits greater attachment of the flow, with separation confined to smaller regions near the blade. During quasi-steady operation, the shedding of vortices into the wake becomes repeatable, and downstream blade--vortex interactions are reduced. The approach based on the prescribed motion of the rotor enables computationally efficient, spanwise-resolved studies of vortex evolution suitable for parametric investigations and the evaluation of flow-control devices.
