No abstract

No abstract

No abstract

No abstract

No abstract

SUMMARYThe variety of flow regimes (steady separated, periodically separated-'Karman vortex street', unsteady turbulent) and their characteristic peculiarities (separation and reattachment points, secondary separation, boundary layer, instability of the shear mixing layer, etc.) require the construction of effective numerical methods, which will be able to simulate adequately the considered flows. MERANGE = SMIF-a splitting method for physical factors of incompressible fluids1-is used for calculations of the steady and unsteady fluid flows past a circular cylinder in a wide range of Reynolds numbers (10' < Re < lo6). The finite-difference scheme for this method is of second order accuracy in the space variables, has minimal numerical viscosity and is also monotonic. Use of the Navier-Stokes equations with the corresponding transformation of Cartesian co-ordinates allows the calculations to be made by one algorithm both in a boundary layer and out of it. The method allows calculations at Re = cc and simulation of d'Alembert's paradox. Some results on the classical problem of the flow around a circular cylinder for a wide range of Reynolds numbers are discussed. The crisis of the total drag coefficient and the sharp rise of the Strouhal number are simulated numerically (without any turbulence models) for the critical Reynolds numbers ( R e z 4 x lo'), and are in a good agreement with experimental data. SMIF = MERANGE METHODOne of the versions of SMIF,' which has been generalized now for three-dimensional problem^,^ non-homogeneous fluids4 and flows with a free surface' is used here for the considered problem.Let the velocity V be known at some moment t, = nz, where z is the time-step and n is number of the time-step. Then the calculation of the unknown functions at the next time level

No abstract

No abstract