基于混合笛卡尔网格的风力机问题数值模拟

STUDY ON HYBRID CARTESIAN GRID METHOD FOR SIMULATING WIND TURBINE FLOWS

基于混合笛卡尔网格方法,对S809翼型和Phase VI叶片的绕流问题进行数值模拟研究。计算网格物面附近生成贴体结构网格,其余部分使用笛卡尔网格进行填充,两者之间通过查找"贡献单元"的方法来进行流场信息的传递。计算方法采用低速预处理方法消除可压缩方程在处理低速问题时的刚性,同时结合旋转坐标系方法考虑风力机旋转效应,进行风力机低速问题数值模拟研究。另外,在Phase VI叶片的计算中,通过笛卡尔网格的局部加密来捕捉尾涡。通过与实验数据及他人数值计算的结果进行对比分析,结果表明该文开发的这套基于混合笛卡尔网格的低速求解器能较为准确模拟风力机叶片轴流状态的流场,并能准确捕捉叶尖涡和叶根涡在风力机下游的发展。

In this paper,a hybrid Cartesian grid method is used to simulate the flows around the S809 airfoil and Phase VI blade. In this method,the body-fitted structured grid is used near the body surface to obtain required viscous nearbody mesh,and the Cartesian grid is generated in the left region. To exchange the data between two grids,the donor cell searching technique is adopted. In order to remove the rigidity of equations at low-speed,the low-speed precondition is used to simulate the wind turbine. For the simulation of Phase VI blade with the axial flow conditions,the rotating coordinate frame is adopted in the present hybrid Cartesian grid method. Furthermore,a local Cartesian grid refining treatment is successfully used to capture the wake vortexes. The results show that the developed low-speed solver on the hybrid Cartesian grid can accurately simulate the axial flow field,and successfully capture the blade tip and root vortexes.