An Experimental Study of Turbulent Uniform Shear Flow in a Nearly Two-Dimensional $90^{\circ}$ Curved Duct (II) - Turbulent Flow Field-

2차원 $90^{\circ}$ 곡관에서 균일전단류의 특성에 대한 실험적 연구 (2) -난류유동장-

An experimental study is made of turbulent shear flows in a nearly two-dimensional 90.deg. curved duct by using the hot-wire anemometer. The Reynolds normal and shear stresses, triple velocity products, integral length scales, Taylor micro length scales and dissipation length scales are measured and analyzed. For a positive shear at the inlet, the afore-mentioned turbulence quantities are all suppressed. However, when the inlet shear flow is negative, they are augmented, i.e., the convex curvature suppresses the turbulence whereas the concave curvature augments it. It is found that the curvature effects are rather sensitive to the triple velocity products than the Reynolds stresses. The evolution of turbulence under the curvature with the different shear conditions is well described by the modified curvature parameter S' and the non-dimensional development time ${\tau}$.'