风力机防冰热载荷计算

Calculation of Wind Turbine Anti-icing Heat Load

采用一种新的基于压力和剪切力的溢流水流量计算方法进行部件表面防冰热载荷数值模拟。求解雷诺平均N-S方程,嵌入k-ωSST湍流模型获得空气流场;欧拉法求解水滴质量和动量守恒方程,获得部件周围水滴速度分布和表面水滴撞击特性;基于传统的Messinger控制容积思想,分析控制体的各项热流,建立质量守恒和能量守恒方程,引入溢流水质量流量计算方程,封闭控制方程,求解方程组获得表面所需的防冰热载荷。采用本文提出的新的流量计算方法获得了NACA0012翼型表面的结冰冰形,并与试验数据进行对比,说明了流量计算方法的正确性。计算分析了不同条件下表面的防冰热载荷分布,结果表明,工作风速和液态水含量的变化既影响了防冰热载荷大小,也影响了溢流范围,而工作温度仅影响防冰热载荷,水滴平均容积直径仅影响溢流范围。

A new method of runback water mass calculation based on both pressure and shear stress is used to simulate the anti-icing heat load.The Reynolds-averaged Navier-Stokes equations are solved to obtain the flow field around the airfoil with k-ω SST turbulence models.The droplet trajectories are acquired using the Eulerian method,based on which the local collection efficiency can be obtained.Adoping the traditional Messinger model,various heat fluxes of the control volume are analyzed,and the runback water mass calculation equation is induced to solve the mass and energy conservation equations.The ice shape on the NACA0012 profile is computed using the current runback water mass calculation method, and the results coincide with the experiment data under the same conditions.It shows that the new method illustrated in this paper is satisfactory.The heat loads in different conditions show that the changes in wind velocity and liquid water content affect both heat load and overflow area,whereas the temperature only affects the anti-icing heat load and the medium volume of water droplets only affects overflow area.