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Metoda cząstek wirowych w modelowaniu ruchu płynu w przestrzeni trójwymiarowej

Kudela H., Regucki P.

Inżynieria Chemiczna i Procesowa

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2006

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T. 27, z. 3/1

817-832

PL

Przedstawiono metodę cząstek wirowych służącą do rozwiązywania trójwymiarowych przepływów nielepkich i lepkich. W algorytmie obliczeniowym zastosowano dwie różne metody redystrybucji "masy" wirowości cząstek na węzły siatki numerycznej: metodę objętości ważonej oraz metodę objętości węzła. Celem podjętych badań było rozstrzygnięcie, która z metod redystrybucji daje lepsze wyniki. Dla przepływów lepkich zastosowano algorytm dekompozycji lepkościowej. Metodę przetestowano, modelując zjawisko "gry wirów" dla przepływu nielepkiego, a dla przepływów lepkich odtworzono zjawisko rekonekcji dwóch pierścieni wirowych.

EN

A vortex particle method for modelling of 3D inviscid and viscous flows has been presented. Calculations were done for two different redistribution methods of vorticity carries by particles on grid nodes: method of weighted volume and method of "volume of a grid node". A viscous splitting algorithm was used: initially the Euler inviscid equations were solved, next the viscous effect was taken into account by the solution of the diffusion equation. Validation of the method was tested by simulation of the "vortex game" phenomenon for inviscid flow and for viscous flow, it was reproduced the reconnection phenomenon of two colliding vortex rings.

2

Experimental investigation of palisade flutter for the harmonic oscillations

Tsyimbalyuk V., Zinkowskij A., Rządkowski R.

Transactions of the Institute of Fluid-Flow Machinery

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2005

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nr 116

3-26

EN

The experimental stand for the flutter analysis was described. In this stand one can measure simultaneously unsteady aerodynamic force and moment with arbitrary combinations of bending and torsion motions of airfoil cascades in the subsonic flow. The cascade is composed of nine blades, four of them are vibrating. Unsteady flow effects have been investigated for subsonic flow in a compressor cascade. Specifically, experimental forced bending and torsion vibration were performed. The aerodynamic work coefficient of bending and torsional cascade vibrations for different interblade phase angles, Strouhal Numbers, and the incidence angles were shown.

3

3D inviscid flutter of IV Standard Configuration. Part.I. Harmonic oscillations

Gnesin V., Rządkowski R.

Transactions of the Institute of Fluid-Flow Machinery

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2002

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nr 111

37-50

EN

A three-dimensional nonlinear time-marching method and numerical analysis for aerolastic behaviour of oscillating blade row of the IV Standard Configuration has been presented. The approach is based on the solution of the coupled fluid-structure problem in which the aerodynamic and structural equations are integrated simultaneously in time. In this formulation of a coupled problem, the interblade phase angle at which stability (or instability) would occur, is a part of the solution. The ideal gas flow through multiple interblade passage (with periodicity on the whole annulus) is described by the unsteady Euler equations in the form of conservative laws, which are integrated by use of the explicit monotonous second order accurate Godunov-Kolgan finite volume scheme and a moving hybrid H-H (or H-O) grid. The structure analysis uses the modal approach and 3D finite element model of the blade. The blade motion is assumed to be a linear combination of modes shapes with the modal coefficients depending on time. The influence of the natural frequencies on the aerodynamic for the Fourth Standard Configuration is shown. The instability regions for the first two modes shapes and the distribution of the aerodamping coefficient along blade length were shown for a harmonic oscillation with the assumed interblade phase angle.

4

3D inviscid flutter of IV Standard Configuration. Part II. Coupled fluid-structure oscilstions

Rządkowski R., Gnesin V.

Transactions of the Institute of Fluid-Flow Machinery

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2002

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nr 111

51-71

EN

A three-dimensional nonlinear time-marching method and numerical analysis for aerolastic behaviour of oscillating blade of the IV Standard Configuration has been presented. The approach is based on the solution of the coupled fluid-structure problem in which the aerodynamic and structural equations are integrated simultaneously in time. In this formulation of a coupled problem, the interblade phase angle at which stability (or instability) would occur, is a part of the solution. The ideal gas flow through multiple interblade passage (with periodicity on the whole annulus) is described by the unsteady Euler equations in the form of conservative laws, which are integrated by use of the explicit monotonous second order accurate Godunov-Kolgan finite volume scheme and moving hybrid H-H (or H-O) grid. The structure analysis uses the modal approach and 3D finite element model of the blade. The blade motion is assumed to be a linear combination of mode shapes with the modal coefficients depending on time. The influence of the natural frequencies on the aerolastic coupled oscillations for the Fourth Standard Configuration is shown. It has been shown that interaction between modes plays an important role in the aerolastic blade response. This interaction has essentially nonlinear character and leads to blade limit cycle oscillations. The sign of the aerodamping coefficient calculated for the harmonic oscillations, may be considered only as a necessary, but not a sufficient condition for self-exited oscillations.

5

Comparison of the 2d and 3d models of flutter of a palisade in an inviscid flow

Rządkowski R., Gnesin V., Kovalyov A

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

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1999

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nr 115

349--356

EN

In recent years the works of the coupled fluid-structure problems appeared. The computational method used to solve this problem was based on a time-marching algorithm, so it was natural to consider a time domain flutter analysis method. The time domain method of flutter analysis is based on the simultaneous integration in time of the equation of motion for the structure and the fluid. In this work the comparison of the 2D and 3D Flutter results for the turbine cascade (IV Configuration) is shown. It was observed that the negative aerodamping coefficient calculated for the harmonic oscillation are not sufficient condition for growing oscillation during fluid-structure interaction.