大气边界层内Magnus叶片设计与研究

Study and Design of Magnus Effect Based Blade in Planetary Boundary Layer

由于地面黏度和地形粗糙度的作用,使得靠近地面的大气边界层处存在较大的风力梯度,该梯度作用于叶片上将产生叶片的转矩变化和俯仰力矩,从而导致输出功率的减少。为了提高输出功率,提出了一种基于马格努斯效应的阶梯型叶片。在整个研究中,将阶梯型叶片简化为分段自旋的圆筒,以NACA4418叶型作为对比研究对象。利用叶素动量理论对两种叶片进行分析与计算,研究表明:大气边界层的存在导致传统叶片的输出功率减少10%,而用阶梯型叶片代替传统叶片,其输出功率将增加近70%。同时采用计算流体动力学进行模拟计算,计算结果表明,传统叶片效率损失估计在4%~5%,而阶梯型叶片效率反而增至60%。

Due to the viscosity and terrain roughness,there is a large wind gradient near ground inside the Planetary Boundary Layer,which will result in the torque variation and the pitching moment of the blade,thus in the change of power output. In order to improve the output power,a new kind of configuration of wind chiral blade is put forward based on Magnus effect. For the whole study,a reference model of NACA 4418 was chosen and compared as the classical blade and the chiral blade was simplified as rotating cylinder in segment. The theory of blade element momentum（ BEM） was used for the analysis and computation of two kinds of blades. The studies show that the loss of efficiency of classical blade due to Planetary Boundary Layer is estimated to 10% and the gain in efficiency when substitute the classical blade by chiral blade reached to nearly 70%. Meanwhile to get a more accurate result,the Computational Fluid Dynamics（ CFD） software FLUENT was used to simulate under the pseudo-rotating condition. The results show that the loss of efficiency of traditional blade is estimated to 4 ~ 5% and the gain in efficiency of chiral blade reached to around 60%.（ Therefore,chiral blade has advantage over classical blade turbine in retrieving energy inside the Planetary Boundary Layer.