低湍流度时尾流湍流切应力和湍流动能的相关

简述了在性能优良、湍流度极低（０．０２％）的西北工业大学低湍流度风洞中用热线风速仪测量翼型近场尾流及边界层速度型、湍流强度、雷诺正应力及切应力等的简况，并着重讨论了极低湍流度下近场尾流中湍流切应力和湍流动能间的相关特性，表明相关值明显不同于常规湍流度的结果。

The Correlation between Reynolds Stress and Turbulent Kinetic Energy in the Near Wake of an Airfoil at Very Low Turbulence Level

The experimental investigation of the turbulent characteristics at trailing edge of aerodynamic bodies increased in recent years3~6].It has important meaning for the improvement of the characteristics of airplane airfoil and those of gas-turbine blade and for the investigation of the noise distribution near the trailing edge.From the investigation of correlation between local Reynolds shear stress and turbulent kinetic energy of Refs. 7 through 9, four conclusions were obtained in Ref.9.But,at that time we had not investigated the effect of turbulence level.In recent years,a low turbulence wind tunnel was constructed at NPU (Northwestern Polytechnical University).In this wind tunnel, we tested airfoil NACA 0012 at very low turbulence level(0. 02%)and some test results for the turbulent characteristics in boundary layer and wake of the airfoll were obtained. This paper describes the correlation between turbulent shear stress and turbulent kinetic energy in the near wake of the airfoil.Results showed that linear relation between turbulent shear stress and turbulent kinetic energy exists in about 50% width of the near wake at very low turbulence level. The proportional constant al is 0. 013. This value is less than the value at higher turbulence level. The proportional coefficient ac is about 0. 13y/b in the centre part of the wake, including the centre line. This proportional coefficient decreases to zero at the outer region of the wake(>0. 6b).