3-DIMENSIONAL SEPARATED FLOW STRUCTURE OVER A CYLINDER WITH A HEMISPHERICAL CAP

Thin-layer Navier-Stokes solutions are obtained for an incompressible laminar flow over a hemisphere-cylinder at 10 degrees, 30 degrees and 50 degrees incidence to exhibit some three-dimensional separated flow characteristics. Some of the results are compared with a previous wate r-tunnel investigation for the same body geometry. Good agreement is f ound, even for some detailed features. Although the geometry is relati vely simple, the separated flow surprisingly embraces a number of intr icate structural characteristics unique to three-dimensional flows. Pa rticularly noteworthy are the separation sequence at increasing incide nce, tornado-like vortices, outward-spiralling vortices, limit cycles, coaxial counter-spiralling patterns and horseshoe vortex systems. Phy sical insights to these new features are offered.