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Symulacja numeryczna opływu modeli budynków metodą dekompozycji pola prędkości

Kosma Z., Motyl P.

Modelowanie Inżynierskie

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2011

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T. 10, nr 41

181-186

PL

Do symulacji numerycznej płaskiego opływu modeli budynków wykorzystano metodę dekompozycji pola prędkości z zaimplementowanymi własnymi algorytmami obliczeniowymi. Najpierw wykonano obliczenia testowe ruchu cieczy lepkiej w kanale z uskokiem jednej ścianki, a następnie symulacje numeryczne opływów modeli: budynku odosobnionego i dwóch budynków usytuowanych blisko siebie. Otrzymane rozkłady składowych prędkości porównano z ich analogicznymi rozkładami obliczonymi za pomocą programu Fluent.

EN

In this work, simulations of flows over models of buildings are based on the numerical solution of the governing fluid flow equations by means of a velocity correction method in which novel improved algorithms have been adopted. Test calculations were firstly carried out for viscous liquid plane flow over the backward-facing geometry. Then, numerical simulations of flow over one isolated model of building and models of two buildings located close to each other were performed.

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Finite difference schemes and the method of lines for solving incompressible viscous flow problems

Kosma Z., Motyl P.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 1

15-35

EN

For the determination of viscous incompressible flows a pure stream-function formulation for the fourth-order equation, the artificial compressibility method, and velocity correction method are employed. Test calculations are performed for various flows inside square, triangular, semicircular and cubic cavities with one uniform wall, the backward-facing step, double bent channels, the flow around an aerofoil at large angle of attack and for flows over models of buildings. Some complex geometrical configurations can be decomposed into a set of simpler subdomains. A practical methodology for the computation of the Navier-Stokes equations in arbitrarily complex geometries is also considered. The simplest approach for specifying boundary conditions near curved or irregular boundaries is to transfer all the variables from the boundaries to the nearest grid knots.

3

Fast Algorithms For Calculations of Viscous Incompressible Flows Using the Velocity Correction Method

Kosma Z., Motyl P.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2008

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Vol. 12, No 3-4

289-301

EN

The velocity correction method is designed to simulate stationary and non-stationary, two- and three-dimensional motions of a viscous incompressible fluid. The basic assumption of this method consists in splitting the velocity and the pressure fields and calculations are performed in two steps. In the first step, a tentative velocity field is determined by simplified equations for momentum conservation. In the second step the Neumann problem for the Poisson equations is solved to obtain the computational pressure, and the velocity components are corrected. A standard method of lines approach and the two grids method are applied in this contribution. Some test calculations for laminar and transitional flows in square and cubic cavities with one moving wall as well as in a backward-facing step are reported.

4

Calculation of viscous incompressible flow around an aerofoil using a modified velocity correction method

Kosma Z.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2005

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Vol. 9, No 1

37-52

EN

The two-dimensional unsteady motion of viscous incompressible fluid around an aerofoil at a large angle of attack has been computed. A modified velocity correction method splitting the velocity field has been designed to solve this problem. First, a tentative velocity field is determined from the equations of momentum conservation for explicit gradients of computational pressure. Then, the Neumann problem for the Poisson equation is solved to estimate the computational pressure, and velocity components are corrected. Test calculations have been made for the case of flow around the NACA 0012 aerofoil with an incidence of 34 degrees. The domain outside the aerofoil was transformed into a canonical one using conformal mapping. Computations were made on 100×100 and 100×200 grids for Reynolds numbers of Re=400, 600 and 1000. Comparison with numerical and experimental data reported in the literature has shown that the method is suitable for simulating 2D external viscous flows.