The Turbulent Shear Flow around a Rotating Cylinder in a Quiescent Fluid : 1st Report, Distribution of Space Correlations

Abstract

This paper deals with some space correlations of velocity fluctuations at two points in the turbulent shear flow around a circular cylinder spinning in a quiescent fluid. One of the dynamical correlation equations and one of the continuity relations are considered, to investigate the <spatial>--- structure of this turbulent flow field. Measured correlation distributions total twelve, of which u_Au_B shows the strongest correlation; and its shape near the peak has large curvature indicating a small eddy. On the other hand, the wide separation range is covered until it tends to zero, which implies the existence of large-scale eddy-lumps. The <ringed>--- eddy structure is well inferred by mixing length theory based on the measured profiles of u_Av_B in the axial direction. Balances of the continuity equation and the dynamic correlation equations are estimated.