Wyniki wyszukiwania - BazTech

1

Modeling of gas flow through valve (CRV)

Duda P., Duda R.

Czasopismo Techniczne. Mechanika

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2015

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Y. 112, iss. 2-M

49--57

EN

The aim of this work is to calculate the effective area of a compressor recirculation valve. Analytical solution and numerical modeling for compressible flow through a valve will be presented. Critical parameters of flow will be determined. Numerical modeling will be performed using ANSYS FLUENT. The results of the numerical solution will be compared with the analytical solutions.

PL

Celem artykułu jest obliczenie powierzchni efektywnej zaworu recyrkulacji. Przedstawione zostaną rozwiązywania analityczne oraz modelowanie numeryczne przepływu czynnika ściśliwego przez zawór. Wyznaczone zostaną parametry krytyczne przepływu. Modelowanie numeryczne przeprowadzone będzie za pomocą programu ANSYS FLUENT. Wyniki z rozwiązania numerycznego porównane zostaną z rozwiązaniami analitycznymi.

2

Compression of gas bubble with inertial coating

Włodarczyk E.

Journal of Technical Physics

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2003

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Vol. 44, no 1

3-17

EN

The compression problem of the polytropic gas bubble coated by the layer of an ideal incompressible liquid has been solved in the closed form. The simple algebraic formulae, which determine the velocity and pressure fields in the liquid layer, as well as the critical (minimal) radius of the maximally compressed bubble, have been derived. The adiabatic and isothermal gas compressions were examined. The time of the compression process was determined. The general solution of the problem was achieved. The solutions, known in the literature of the similar but simplified problems, result from our solution as particular cases.

3

Thermomechanical coupling between the flow of steam and deformation of the valve during start-up of the 200 MW turbine

Bielecki M., Karcz M., Radulski W., Badur J.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2001

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Vol. 5, No 2

125-140

EN

The lifetime estimation of power station structures and components, subjected to fatigue loading, is essential for determining the moment of repair or replacement. Therefore the degradation behaviour and damage development within material should be very well understood. This research focuses on a fluid-solid interaction that has been developed in Finite Volume Method software for description of heat and flow loading on a cut-off valve and Finite Element Method software for conduct researches on fatigue and creep damage of the valve material.

4

The axisymmetric compressible boundary layer flow along a circular cylinder

Elliott J. W.

Applied Mechanics and Engineering

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2000

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Vol. 5, no 3

715-751

EN

A numerical and analytical investigation of the compressible axisymmetric boundary-lager flow over a circular cylinder is presented for both adiabatic flow and the case of heated or cooled walk. First, a numerical solution to the governing equations is presented for a variety of wall conditions. The remainder and majority of the paper is then concerned with an analysis of the far-downstream flow where curvature becomes a dominant feature. Here the flow takes on a double structure, with an Oseen type of outer flow. The problem reduces to matching to an inner solution which, in contrast to the incompressible case, is found to be non-trivial. Three forms of the inner solution are constructed, firstly to justify obtaining a new result and secondly to rebut the assertion that matching is only possible for a single approach. Further the use of a general power law form for the viscosity law is considered. The resulting asymptotic forms are then compared with the numerical results of the far downstream flow.

5

Absolute instability of compressible three-dimensional flow

Tuliszka-Sznitko E.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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1999

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Vol. 3, No 1

5-16

EN

In the present paper the instability character (absolute/convective) of compressible viscous flow around geometries rotating in uniform flow is analysed. The linear local stability theory is used to investigate the boundary layer stability. Following the works of Briggs and Bers in the field of plasma physics, the absolute instability region is identified by singularities of dispersion relation called pinch - points. Calculations have been made for different Mach numbers and wall temperatures.

6

A Parallel adaptive code for compressible Navier-Stokes simulations

Banaś K.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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1999

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Vol. 3, No 1

17-37

EN

The paper presents a finite element code for compressible flow simulations. The code has two important features: adaptivity to increase accuracy of computations by selectively refining a finite element mesh and efficient parallel performance due to a special implementation based on concept of patches of elements. The algorithm for approximating the compressible Navier-Stokes equations is a version of the stabilized finite element method. Three time integration strategies are implemented, explicit, linear implicit and nonlinear implicit, and the GMRES method is used to solve systems of linear equations. For parallel simulations the code uses a special algorithm for mesh partition. The performance of the code is tested for two examples of supersonic flows: one inviscid and one viscous.