National Wind Technology Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA.
Philos Trans A Math Phys Eng Sci. 2013 Jan 14;371(1985):20120421. doi: 10.1098/rsta.2012.0421. Print 2013 Feb 28.
This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally periodic precursor simulation is performed to create turbulent flow data. Then those data are used as inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modelled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. We found that staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement. For example, using a larger precursor domain would better capture elongated turbulent structures, and including salinity and temperature equations would account for density stratification and its effect on turbulence. Additionally, the wall shear stress modelling could be improved, and more array configurations could be examined.
本文介绍了我们在进行潮汐涡轮机阵列流的大涡模拟方面的初步工作。首先，进行水平周期前导模拟以创建湍流流动数据。然后，将这些数据用作两排深且无限宽的潮汐涡轮机阵列的入口。使用旋转执行器线对涡轮机进行建模，并使用有限体积法求解控制方程。在研究涡轮机产生的尾流时，我们观察到流入的垂直剪切与尾流旋转相结合导致了侧向尾流不对称。此外，还模拟了各种涡轮机配置，并研究了相对于孤立涡轮机的总功率产生情况。我们发现，在模拟配置中交错连续排的涡轮机可以在使用最小下游排距的情况下实现最大效率。在非交错阵列中，连续下游的反向旋转涡轮机显示出较小的益处。这项工作确定了需要改进的领域。例如，使用更大的前导域可以更好地捕捉到拉长的湍流结构，并且包括盐度和温度方程可以考虑密度分层及其对湍流的影响。此外，可以改进壁面剪切应力建模，并可以研究更多的阵列配置。
