PMD (Parallel Multi-domain Decomposition) is an MPI based Fortran 90 module which objective is to parallel-solve positive definite linear elliptic second order equations. It has been used to solve unsteady Navier-Stokes equations in order to simulate an axisymmetric incompressible viscous fluid flow inside a centrifugal pump. In this paper, we will present a brief description of the implementat...

The issue of appropriate time discretization methods for the unsteady incompressible Navier-Stokes equations is considered from a practical perspective. Conventional implicit time-stepping algorithms are not feasible for long-time simulations since they inherit the quadratic nonlinearity of the steady-state equations. As a result, two new linearized versions of the 'pure' algorithms are analyze...

In this paper we consider nite element methods for a degenerate elliptic-parabolic partial diierential system which describes the ow of two incompressible, immiscible uids in porous media. Local mesh reenement techniques for solving this degenerate system are discussed. 1. TWO-PHASE FLOW EQUATIONS In this paper we consider nite element methods for the ow of two incompressible, immiscible uids i...

A review of recent work and new developments are presented for the penalty-function, finite element formulation of incompressible viscous flows. Basic features of the penalty method are described in the context of the steady and unsteady Navier-Stokes equations. Galerkin and “upwind” treatments of convection terms are discussed. Numerical results indicate the versatility and effectiveness of th...

Abstract In this paper the design and analysis of a dimensionally consistent stabilization operator for a time-discontinuous Galerkin least-squares finite element method for unsteady viscous flow problems governed by the incompressible Navier-Stokes equations, is discussed. The analysis results in a class of stabilization operators which satisfy essential conditions for the stability of the num...

In this paper it is attempted to investigate the behavior of an inviscid flow in the meridional plane of an axial flow compressor. For this purpose the 3-D unsteady Euler equations in cylindrical coordinate are averaged in tangential direction. Therefore, the equations are reduced to a 2-D system. By averaging the tangential component of momentum equation, a blade force will result. Axial and r...

An efficient and accurate numerical scheme is presented for the three-dimensional Navier–Stokes equations in primitive variables in a cylinder. The scheme is based on a spectral-Galerkin approximation for the space variables and a second-order projection scheme for time. The new spectral-projection scheme is implemented to simulate unsteady incompressible flows in a cylinder. c © 2002 Elsevier ...

In this paper, numerical simulation for a two-dimensional viscous and incompressible flow past the elliptical airfoil is presented by Random Vortex Blob (RVB). RVB is a numerical technique to solve the incompressible, two-dimensional and unsteady Navier-Stocks equations by converting them to rotational non-primitive formulations. In this method, the velocity vector at a certain point can be cal...

Unsteady two-dimensional stagnation point flow of an incompressible viscous fluid over a flat deformable sheet is studied when the flow is started impulsively from rest and the sheet is suddenly stretched in its own plane with a velocity proportional to the distance from the stagnation point. After a similarity transformation, the unsteady boundary layer equation is solved numerically using the...

We demonstrate that the requirement of Galilean invariance determines the choice of H function for a wide class of entropic lattice-Boltzmann models for the incompressible Navier-Stokes equations. The required H function has the form of the Burg entropy for D=2, and of a Tsallis entropy with q=1-(2/D) for D>2, where D is the number of spatial dimensions. We use this observation to construct a f...