Similarity in the turbulent near wake of bluff bodies

Velocity correlation structure in the turbulent near wakes of bluff bodies

“…Sweep rate 10 msec/cm.for a value of ^=0.5, both of the hot wires are immersed in turbulent flow. At X=^ 1.0, which is the approximate location of low-pressure trough and the maximum wake width (Sullerey et al6 ), short patches of laminar flow appear on the lower trace. For larger values of X the hot wire corresponding to the upper trace is in the region of diffuser-type outer flow, and the interface intermittency superimposed on the vortex shedding oscillations is evident.…”

“…properties in the turbulent near wakes have been investigated experimentally by Calvert 5 for axisymmetric models and by Sullerey et al 6 for two-dimensional bluff body models. The present work is a report of data on streamwise velocity correlation structure measured in the turbulent near wakes of two-dimensional bluff body models.…”

Flows in a Model Furnace and Heat Exchanger

“…In the investigation of the wake past axisymmetric bluff bodies, pressure measurements and also estimation of the recirculatioon bubble length behind a wide variety -128of cross-sectional and forebody shapes (for example Carmody (1964), Davies and Béer (1971), Calvert (1967), Winterfield (1965), Sullerey et al (1975)), have shown that bluffer bodies, which give rise to large streamline deflections at their trailing edge, result in larger pressure drops, longer and wider recirculation zones. (1965) suggested that the length of recirculation is influenced more by bluffness than by blockage, at least for isothermal flows of less than 25% blockage.…”

“…Also, in plane flows increases in the maximum pressure drop are associated with decreasing turbulent length scales. The opposite is true for axisymmetric geometries,Sullerey et al (1975).Most of the recent work has concentrated on the backward facing step, since this is the simplest two-dimensional reattaching flow. It differs that over an obstacle in that in the first case separation at the sharp corner occurs with the streamlines approaching nearly parallel to the step surface, whereas in the case of a thin obstacle there is a significant upstream influence, due to streamline curvature before the obstacle, which is carried also downstream of separation.…”