【作者】 周捍珑； 杨华； 李壮； 石亚丽； 汤方平；

【Author】 Zhou Hanlong;Yang Hua;Shi Yali;Tang Fangping;School of Water Conservancy and Energy Power Engineering,Yangzhou University;

【机构】 扬州大学水利与能源动力工程学院；

【摘要】 本文采用速度势面元法,基于螺旋桨的尾涡模型提出了适用于风力机的幂指数膨胀尾涡模型,编写了风力机气动性能的面元法预测程序。以直径为4.5m的三叶水平轴MEXICO风轮为计算模型,研究了面元网格数对气动性能预测精度的影响,研究表明,网格数过多将导致面元太小,计算时易出现奇点而引起数值计算发散。通过对不同风速下近尾迹区域分别为1R(R为风轮半径)、2R,3R、4R时0.6半径断面上的压力系数的对比分析,发现面元法预测风力机气动性能时,风轮下游近尾迹范围取4倍风轮半径时可以获得较高的数值计算精度。将面元法预测的压力系数与CFD计算及实验数据进行对比,面元法对低风速工况的叶片吸力面和高风速工况的叶片压力的压力系数计算值与实验值吻合很好;而且面元法计算速度比CFD计算速度快10倍,对计算机硬件要求低。考虑粘性和流动分离的影响可以进一步提高面元法的预测精度。具有很好的应用前景。更多还原

【Abstract】 A computational aerodynamic method was proposed and implemented for the MEXICO rotor which diameter is 4.5m. This method is built on the fundamental of panel method and a new wake model is proposed. The new wake model refers to the wake model of propeller,and took the specialties of wind turbine wake into consideration. The whole calculation process is executed by a code written in FORTRAN language. The impact on the accuracy of computational aerodynamic prediction in different numbers of rid is studied. Research shows that if the panel is too small,there will be a singularity. In this paper,different regions(1R,2R,3R,4R) of near wake in different wind speed were calculated in order to study the discrepancies caused by different near wake ranges. The results show when the near region is more then 4 times the rotor radius,the tolerance no longer changes. This means that near wake region take 4 times rotor radius can meet the precision requirement. Last but not least,the precisions of predicted pressure coefficients between panel method and CFD were compared to. According to the results analysis,both of the methods coincide with experiment date. It is observe that the accuracy of panel method is more accurate in suction side with low wind speed and in pressure side with high wind speed. Nevertheless,the operating rate of panel method is extremely faster then CFD,more then 10 times. If the infections of viscosity and flow separation are taken into condition,the prediction accuracy of panel method will be improved. Above all,the developed model provides an accurate and rapid prediction method for the normal aerodynamic performance of HAWT,especially for the wind turbine with variable speed.更多还原