不同湍流模型对水平轴风力机三维粘性气流特性的影响

对某水平轴风力机叶片附近的三维湍流流场进行了数值模拟,其中在7、15、25m/s 3种不同工况下分别采用S-A、Standard k-ε、RNG k-ε和SST k-ω4种湍流模型。计算结果表明:随着来流速度的逐渐增大,叶片吸力面的分离流沿叶根向叶尖方向逐渐发展,且由于三维旋转效应使得展向流动逐渐增强。和相关实验结果比较,选择不同的湍流模型对数值模拟结果有明显影响,其中RNG k-ε和SST k-ω两种模型可以获得较好的压力分布计算精度。综合考虑压力分布、功率系数和推力系数在不同工况下与实验结果的比较,选择SST k-ω湍流模型较适合模拟该水平轴风力机周围复杂的三维湍流流动。

SEPARATED FLOWS AROUND HAWT BLADE WITH DIFFERENT TURBULENT MODELS

Complex three dimensional turbulent flows near a HAWT blade were numerically simulated with three cases of the inlet velocity being 7ntis, 15m/s and 25m/s, respectively. The results show that the separated flow gradually grows from the root of the blade to that tip with the increasing of inflow velocity. Meanwhile, the flow along spanwise is gradu-ally extended. The computed results and its comparisons with the experimental data were presented, which shows that the pressure distributions can be predicted more accurately by the RNG κ-εand SST κ-ωmodels than other models. Further study gives the flow properties including pressure distributions on the blade surface can be predicted more accurately by using SST κ-ωturbulence model than using S-A, Standard κ-ε, RNG κ-ε models.