离心力对于旋转叶片表面积冰影响的数值模拟研究

为了加深对旋转叶片表面积冰现象的认识,发展了一种适用于旋转表面积冰预测的数学模型,并采用该模型研究了离心力对于旋转叶片表面积冰的影响。通过对积冰控制体内的由于撞击水滴形成的薄水膜流动的质量、动量和能量守恒进行分析,发展了旋转贴体非正交曲线坐标系下的积冰模型并给出了相应的计算方法。所发展模型的动量方程中考虑了离心力对水膜流动的影响,并且在能量方程中考虑了净流出水带走的能量。采用文献中旋翼表面的积冰试验结果对所发展的模型和计算方法进行了验证,所计算得到的冰厚与试验结果吻合较好,计算得到的冰厚精度相比于LWICE软件有所提高。计算结果还表明,离心力增大会导致水膜速度在叶片展向上的分量变大,致使流出控制体的水质量增加,最终导致冰厚在驻点附近略微变小。

Numerical Study of Effects of Centrifugal Force on Ice Accretion on a Rotor Blade

Ice accretion on rotor such as helicopter rotors, fan rotors of a engine can be harmful to flight safety. This paper developed an icing model in a rotating body-fitted non-orthogonal coordinate system based on the analysis of mass, momentum, and energy conservation of the thin water film in the icing control volume which is caused by the impinged super cooled droplets. The calculation scheme was also given in this paper. The icing model developed in this paper considers the effect of centrifugal force on the movement of the water film in the momentum-conservation equation and the energy taken away by the water flows out of the control volume in the energy-conservation equation. The model was validated by using the experimental data from literature, and the calculated results match well the experimental data. The model was also used to study the effect of the centrifugal force on ice accretion on the rotor. Results show that with the increase of centrifugal force, the velocity component of water film in the span direction becomes larger, and more water will be drainage out of the control volume which leads a slight decrease of the ice layer thickness near the stationary point