Author(s): G. M. Morgunov; V. V. Frolov; S. N. Shepelev
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Abstract: Last time there were a great number of works devoted to theproblem of effective calculation □f three-dimensional turbulentf1ows in a complex regions.In particular,there are many casesof hydromechanical problems in which solid boundaries are movingrelatively to each other with a smal1 distance between them.Inspite of mathematical models diversity one can mark outtwo greatclasses of such a models.In the first class the Navie-Stocke'sequations are being solved [11.In the second c1ass turbulenceis being modelled by means of three-dimensional boundary layer[2].For that case flow in a subregion of main f1ow is consideredto be nonviscous.In both cases for c1osing hydrodynamics conser-vation equations authors had to use empirical and_semiempiricalrelations between characteristics of turbulence.Both of thesedirections of investigation_meet with essential difficulties on theway of its development.In [3],for example,lack of stationary.solution of three-dimensional Navie-Stocke's equations is beingproved at least forfluids with a small viscosity,and in [4jproblems of numerical procedures stability of equations solvingand connected with it conceptions of grid regularity and viscousityare being examined.If configuration of calculated region is complexenough a wel1-known boundary layer assumptions and methods of calcu-lation such as finite differences or finite elements becomeuneffective.So,in [5]it is being pointed out the uneffective-ness of such methods because of 1ack of necessary accuracy ofcalculations on a grid with great heterogeneity of geometricalcharacteristics.When we talk about heterogeneity of geometry inelastostatics it applies to different concentrators of strains(cuts,splits etc.)and in hydrodynamics it means presense(side by side with the main f1ow)of secondary flows threw clearences.
Year: 1991