Multilevel panel method for wind turbine rotor flow simulations
Multilevel panel method for wind turbine rotor flow simulations
复制标题
风力涡轮机转子流动模拟的多级面板方法
DOI：
10.2514/6.2017-2001
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
A. V. Garrel
中科院分区：
文献类型：
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作者：
A. V. Garrel
目前使用的风力涡轮机空气动力学仿真方法主要分为两类：一类是传统的低逼真度工程模型组，另一类是基于Navier-Stokes方程的计算昂贵的CFD方法组。对于工程环境，搜索的是“中等保真度”风力涡轮机模拟方法，该方法弥补了计算成本低的低保真方法和计算成本高的CFD方法之间的差距。
本研究的重点是发展的理论和实际实施的快速多级积分变换的计算机程序。我们利用这种多层次的计划在一个低阶面元方法。计算结果表明，对于风力涡轮机转子尾流的模拟，计算量由传统面元法的O（N2）减少到本方法的O（N）。这意味着计算工作量减少到与问题大小N线性增长，N是面板的数量。
作为验证试验的面元法，结合MLMIC方案的尾流的影响，被应用到墨西哥风洞实验。计算结果与实验测量的该模型风力机涡轮机5个叶片截面的压力分布以及最先进的求解雷诺平均Navier-Stokes方程的方法的结果吻合较好。与传统的面元法相比，MLMIC方案减少了三个转子叶片及其尾流表面的面元离散化，尾流变形的计算时间减少了150倍。
通过计算时间和模拟精度方面的结果，我们得出结论，面元法在工业工程环境中被重新定位为风力涡轮机转子叶片的有价值的中等保真度数值设计工具。因此，新方法是可再生（风能）能源的重要一步。
Simulation methods of wind turbine aerodynamics currently in use mainly fall into two categories: the first is the group of traditional low-fidelity engineering models and the second is the group of computationally expensive CFD methods based on the Navier-Stokes equations. For an engineering environment the search is for “medium fidelity” wind turbine simulation methods that bridge the gap between the computationally inexpensive low-fidelity methods and the computationally expensive CFD methods.
The present study focuses on the development of the theory and the practical implementation of a fast multilevel integral transform in a computer program. We utilize this multilevel scheme in a low-order panel method. It is demonstrated that for the simulation of the wake flow of wind turbine rotors the computational burden is reduced from O(N2) for a conventional panel method to O(N) for the present method. This implies that the computational effort is reduced to grow linearly with problem size N, with N the number of panels.
As a validation test the panel method, combined with the MLMIC scheme for the influence of the wake, is applied to the MEXICO wind tunnel experiment. The numerical results show good agreement with the experimentally obtained pressure distributions at 5 blade sections of this model wind turbine as well as the results of a state-of-the-art solution method for the Reynolds-averaged Navier-Stokes equations. Compared to a conventional panel method, the MLMIC scheme reduces for the used panel discretization of the three rotor blades and their wake surfaces, the computation time for the wake deformation by a factor 150.
With the results achieved in this thesis regarding computational times and simulation accuracy we conclude that the panel method is repositioned as a valuable medium fidelity numerical design tool for wind turbine rotor blades in an industrial engineering environment. The new method thus forms an important step for renewable (wind) energy.