Wyniki wyszukiwania - BazTech

1

Numerical investigation of vortex wake patterns of laminar flow around two side-by-side cylinders

Nguyen Van Luc, Ho Duy Khanh

Archive of Mechanical Engineering

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2022

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LXIX, nr 3

541--565

EN

The laminar flow around two side-by-side circular cylinders was numerically investigated using a vortex-in-cell method combined with a continuous-forcing immersed boundary method. The Reynolds number (Re) of the flow was examined in the range from 40 to 200, and the distance between the cylinders varies from 1.2D to 6D, where D is the cylinder diameter. Simulation results show that the vortex wake is classified into eight patterns, such as single-bluff-body, meandering-motion, steady, deflected-in-one-direction, flip-flopping, anti-phase-synchronization, in-phase-synchronization, and phase-difference-synchronization, significantly depending on the Re, the cylinder distance, and the initial external disturbance effects. The anti-phase-synchronization, in-phase-synchronization, and phase-difference-synchronization vortex patterns can be switched at a low Re after a long time evolution of the flow. In particular, the single-bluff-body and flip-flopping vortex patterns excite the oscillation amplitude of the drag and lift coefficients exerted on the cylinders

2

Fluid motion modelling using vortex particle method on GPU

Rogulski Ł., Deorowicz S.

Studia Informatica

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2013

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Vol. 34, nr 1

31--48

EN

In this paper we present the vortex-in-cell method aimed at graphic processor units. Inviscid fluid model is examined in domain with periodic boundary conditions. The leap-frogging vortex rings simulation results are presented with sample vortex rings collision visualization. At the end the GPU solver performance advantage over CPU solver is presented.

PL

W pracy prezentujemy metodę obliczeniową wir-w-komórce zaimplementowaną na układach graficznych. Za model ośrodka został przyjęty płyn nielepki wraz z periodycznymi warunkami brzegowymi. W pracy przedstawiono wyniki symulacji dla gry wirów oraz przykładowe wizualizacje z wykorzystaniem cząsteczek markerów. Pod koniec została przedstawiona analiza uzyskanego przyspieszenia algorytmu na GPU względem wersji na CPU.

3

Modelowanie dynamiki pierścienia wirowego metodą cząstek wirowych z wykorzystaniem obliczeń równoległych na kartach graficznych

Kosior A., Kudela H.

Modelowanie Inżynierskie

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2012

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T. 13, nr 44

145-150

PL

W artykule przedstawiono metodę wiru w komórce (VIC -Vortex in Cell) służącą do rozwiązywania równań ruchu płynu. Ze względu na długi czas obliczeń przy użyciu jednego procesora w pracy została przedstawiona implementacja metody VIC z wykorzystaniem obliczeń równoległych w środowisku kart graficznych. Uzyskano dzięki temu 46-krotne skrócenie czasu obliczeń. Przedstawione zostały dwa przypadki testowe. Pierwszy prezentuje poprawność obliczeń prowadzonych z wykorzystaniem kart graficznych. Drugi pokazuje wpływ lepkości na prędkość przemieszczania się pierścienia wirowego.

EN

The paper presented the Vortex in Cell (VIC) method for solving the fluid motion equations in 3D. Due to the long time of computation on single processor the parallel implementation of the VIC method was presented. The speed-up for the entire VIC method implementation on the GPU was 46 times. Two test cases were presented. First one, shows correctness of the parallel implementation on GPU. Second example shows influence of viscosity on the translation velocity of the vortex ring.

4

Viscous flow modeling using the vortex particles method

Kudela H., Malecha Z. M.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2009

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Vol. 13, No 1-2

15-32

EN

The vortex particle method is an easy and attractive tool to analyze flow phenomena by investigating vorticity fields and the generation of vorticity at solid walls. The vorticity generation at the walls and its introduction to the flow is of fundamental significance for understanding such phenomena as transition to turbulence, boundary layer separation in an eruptive way, and Hortex structures regeneration. In the present study the vortex-in-cell usefulness of the method has been tested using a variety of simple test problems: the Poiseuille flow, the second Stokes problem, the cavity, the backward step flow, the vortex dipole interaction with the wall, and the flow past a square cylinder in the vicinity of a wall in order to illustrate the correctness and usefulness of the Hortex particle method.

5

Modelowanie zagadnień zewnętrznych metodą cząstek wirowych

Kudela H., Kozłowski T.

Systems : journal of transdisciplinary systems science

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2008

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Vol. 13, spec. iss. 2/2

1--8

EN

Vortex-in-cell method was used for the modeling of the flow over the solid body in infinite domain. This kind of problem belongs to the external problems. One of the main difficulty in external problems related to the necessities of putting the boundary condition far from the body. It stems from the fact that we use in our calculation the numerical grid and the computational domain must be finite. It was presented how one can obtain the exact value of boundary condition far from the solid body. The vortex particle method with the algorithm correction of the far field boundary value was tested for flow over the circular and elliptical, thin cylinder. It was obtained very good agreement with the experiment and with the calculations that were done by the other researchers.