风洞洞壁对风力机翼型气动特性的影响分析  

Analyzing the effect of wind tunnel wall on the aerodynamic performance of airfoils

作　　者：白井艳[1,2,3,4] 张磊[2,3] 李星星[2,3] 杨科[2,3] 

机构地区：[1]中国科学院广州能源研究所,广州510650 [2]中国科学院工程热物理研究所,北京100190 [3]中国科学院风能利用重点实验室,北京100190 [4]中国科学院大学,北京100049

出　　处：《中国科学：物理学、力学、天文学》2016年第12期47-56,共10页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金资助项目(编号:51476171)

摘　　要：本文通过风洞试验测量和计算流体动力学(Computational Fluid Dynamics,CFD)数值模拟的研究结果,分析了风洞洞壁对风力机翼型气动特性的影响.试验风洞为中国科学院工程热物理研究所(Institute of Engineering Thermophysics,IET)低速回流风洞,所选用的翼型为DU91-W2-250.数值模拟采用有洞壁、无洞壁、无侧壁三种方式进行计算,通过对比试验和数值计算结果验证了采用CFD数值模拟分析风力机翼型洞壁效应的可行性.通过数值模拟分析并与经典映像法及Maskell洞壁修正方法对比,得出:风洞中,上下壁面的存在使流动在风洞壁面形成一定厚度的边界层,造成气流的通道面积减小,来流有效速度增加,并引起翼型升力系数C_l和阻力系数C_d增加;风洞侧壁诱导翼型段表面的展向流动、抑制了翼型表面的流动分离,减小了翼型弦向流动速度,引起翼型升力系数减小,阻力系数增加;小攻角时风洞侧壁对翼型表面流动的影响可以忽略,翼段表面流动保持二维性,大攻角时风洞侧壁干扰效应显著,其影响程度超过风洞上下壁面,与无洞壁相比,风洞壁的存在使升力系数减小,阻力系数增加;经典映像法及Maskell方法因未考虑洞壁边界层的影响,并不适用于风力机翼型大攻角流动时的洞壁效应修正问题,大攻角修正时应考虑风洞侧壁影响,对升力系数给予增量;同时对于大攻角流动,翼型本身流动已不具有二维性,其气动性能的测量应采用多截面压力测量或天平测力方法.This paper analyzes the effect of wind tunnel wall interference on the airfoil aerodynamic performance, based on the results of experiment and CFD numerical simulation. The experimental measurement was made in lET using the low-speed and closed wind tunnel. The airfoil was DU91-W2-250. The numerical simulation with tunnel wall （wall）, without tunnel wall （no wall） and without side tunnel wall （no side wall） were performed. Through the comparison the results between Exp and CFD, it is feasible to use CFD numerical simulation in this paper. And we get the following conclusions： the upper and lower tunnel walls make the flowing area decrease and the velocity increase due to the thickness of boundary layer on the walls, and they also casuse that 6＇1 and Cd increase. The side tunnel walls cause span-wise flowing and delay the flow separation on the surface of airfoil, meanwhile, they cause that the velocity decreases, C1 decreases and Cd increases. At small angles of attack, the effect of side amnel walls on the flowing of airfoil surface can be neglected. However, this effect is very significant at large angles of attack. The classical method can not work well at large angle of attacks for the correction of wall interference in wind tunnel because it doesn＇t consider the effect of tunnel wall boundary layer. The C1should be increased through the correction, meanwhile, it is found that the flowing is not two-dimensional flow at large angles of attack in the free-air condition, so we suggest that the pressure measurement with more cross sections or using balance method should be used to obtain the aerodynamic performance of airfoil.

关 键 词：风洞试验 数值模拟 洞壁效应 

分 类 号：TK83[动力工程及工程热物理—流体机械及工程]