Asymptotic theory of separation flow
Abstract
Separation flow at a body surface was analyzed by the asymptotic method according to the theory of a turbulent boundary layer. The velocity field in the region around the separation point was determined for an ideal fluid with free streamlines and assumes that the Reynolds number approaches infinity, with the pressure gradient along the surface and the curvature of a streamline described by known asymptotic expansions. The two dimensional Reynolds equation of a boundary layer are formulated in a system of Cartesian coordinates with the origin at the separation point and its two axes respectively on and normal to the plane surface. The region of the stream is divided into five sublayers, two converging to and terminating at the separation point and three continuing beyond. Backstreams appear within a thin laminar sublayer behind the separation point. The velocity profiles in the sublayers are calculated from the corresponding systems of equations, those for turbulent sublayers requiring closure with a model of turbulence and use of the Heaviside function at the separation point, and with the solutions appropriately collocated. The turbulence model is based on the Prandtl mixing path hypothesis and a recurrence relation for the coefficients.
- Publication:
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USSR Rept Eng Equipment JPRS UEQ
- Pub Date:
- April 1984
- Bibcode:
- 1984RpEE........28S
- Keywords:
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- Asymptotic Methods;
- Cartesian Coordinates;
- Separated Flow;
- Turbulent Boundary Layer;
- Flow Distribution;
- Numerical Analysis;
- Prandtl-Meyer Expansion;
- Reynolds Number;
- Surface Properties;
- Turbulence Models;
- Fluid Mechanics and Heat Transfer