V.O.Gorban, I.M.Gorban Vortical flow pattern past a square prism: numerical model |
Applied hydromechanics, Vol. 7 (79) ¹ 2, (2005) |
| A coupled Larangian-Eulerian numerical scheme for modeling the laminar flow of viscous incompressible fluid past a square prism at moderate Reynolds numbers is developed. The two-dimensional Navier-Stokes equations are solved with the vorticity-velocity formulation. The convection step is simulated by motion of Lagrangian vortex elements and diffusion of vorticity is calculated on the multi-layered adaptive grid. To reduce the dynamic loads on the body, the passive control techniques using special thin plates are proposed. The plates are installed either on the windward side of prism or in its wake. In the first case, the installation of a pair of symmetrical plates produces substantial decreasing the intensity of the vortex sheets separating in the windward corners of prism. In the second case, the wake symmetrization is achieved with the help of a long plate abutting upon the leeward surface. Both the ways bring narrowing of the wake and, as a result, decrease of the dynamic loads. With optimal parameters of the control system, the drag reduction is shown to decrease considerably. |
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| TEXT LANGUAGE: Ukrainian |