Mathematical modeling of transient separation flow around circular cylinder
Abstract
A numerical method is proposed for complete solution of the problem of transient separation flow of a viscous fluid around a cylinder. It is based on existing models of a boundary layer and on assuming an ideal medium, and it requires no additional empirical data. The potential flow outside the boundary layer is mathematically modeled by a system of N+1 dimensionless algebraic equations in series form describing the circulation of discrete vortices. At time zero N of these equations represent the condition of impermeability of the cylinder surface and one represents the condition of zero tangential velocity at the stagnation point. For subsequent instants of time the N equations are modified to represent the condition of impermeability at successive points on the surface and the one equation is modified to represent the Thomson theorem of constant circulation around a contour enclosing both the body and its trail. The boundary layer is simulated not only on the front from the stagnation point to the separation point on each side, but also on the rear side with backstreams within the zone between the two separation points there. Viscous flow in the boundary layer is described by the conventional system of differential equations of a nonsteady layer, with both kinematic and eddy viscosity as parameters.
 Publication:

USSR Rept Eng Equipment JPRS UEQ
 Pub Date:
 April 1984
 Bibcode:
 1984RpEE........23B
 Keywords:

 Boundary Layers;
 Circular Cylinders;
 Mathematical Models;
 Separated Flow;
 Viscous Flow;
 Aerodynamic Coefficients;
 Differential Equations;
 Stagnation Point;
 Fluid Mechanics and Heat Transfer