STRATIFIED FLOW PAST A SPHERE

The flow of a linearly stratified fluid past a sphere is considered experimentally in the Froude number Fi, Reynolds number Re, ranges 0.005 less-than-or-equal-to Fi less-than-or-equal-to 20 and 5 less-than-or-equal-to Re less-than-or-equal-to 10000. Flow visualization techniques and density measurements are used to describe the rich range of characteristic flow phenomena observed. These different flow patterns are mapped on a detailed Fi against Re flow regime diagram. In most instances the flow patterns were found to be very different from those observed in homogeneous fluids. Vortex shedding characteristics. for example, were found to be dramatically affected by the presence of stratification. Where possible, the results are compared with available analytical and numerical models.