风沙环境对NACA-0012翼型气动性能的影响

Effect of sand-laden wind environment on aerodynamic characteristics of airfoil NACA-0012

采用离散相模型对风沙环境下风力机传统对称翼型NACA-0012的气固两相流动进行数值模拟,结合k-ε湍流模型求解雷诺时均N-S方程,研究风沙环境下NACA-0012翼型的升、阻力系数随固相质量浓度和颗粒中值直径变化的规律.结果表明,同一中值直径时,固相质量浓度对翼型的升、阻力系数影响较小,随着固相质量浓度增大,翼型的升力系数先迅速增大了洁净空气时的8.2%左右,然后趋于稳定,当固相颗粒质量浓度大于1.02kg/m3后,升力系数再持续增大;阻力系数先略有减小,然后趋于稳定,当固相颗粒质量浓度大于1.02kg/m3后,阻力系数再持续增大.同一固相质量浓度时,沙尘的颗粒直径对风力机翼型的升、阻力系数影响较大,颗粒直径越小,对翼型的升、阻力系数的影响越大,随着颗粒中值直径的增大,翼型的升力系数先迅速减小再逐渐增大,最后趋于稳定;阻力系数先迅速增大再逐渐减小,然后略有增大,最后趋于稳定.

The discrete phase model is used to simulate numerically the gas-solid two-phase flow over the traditional airfoil NACA-0012 for wind turbines running in sand-laden wind environment.The Reynolds equations（time-averaged Navier-Stokes equations）with k-εturbulence mode are solved to study the variation pattern on lift and drag coefficients with solid-phase mass concentration and particle mean diameter of sand.It is found that when mean diameter is identical,the solid-phase mass concentration will have little influence on lift and drag coefficients.With the increase of solid-phase mass concentration,the lift coefficient will increase at first rapidly by about 8.2%of that of clean air,then become stable,and then increase again when mass concentration is larger than 1.02kg/m3.The drag coefficient will decrease a little at first,then become stable,and then,when the mass concentration is larger than 1.02kg/m3,the drag coefficient will continuously increase.When solid-phase mass concentration is identical,the sand particle diameter will have a greater effect on lift and drag coefficients,the smaller the particle diameter is,the larger the effect on the lift and drag coefficient will be.The lift coefficient will decrease rapidly at first and then gradually increase with particle of median diameter,and become stable finally.With the increase of particle median diameter,the drag coefficient will increase rapidly at first,then gradually decrease,and then increase again a little,and become stable finally.