The unstable flow with rotating-stall-like (RS) effects in a rotor-cascade of an axial compressor was numerically investigated. The RS was captured with the reduction in mass flow rate and increasing of exit static pressure with respect to design operating condition of the single rotor. The oscillatory velocity traces during the stall propagation showed that the RS vortices repeat periodically,...

The paper studies an iterative solver for algebraic problems arising in numerical simulation of blood flows. Here we focus on a numerical solver for the fluid part of otherwise coupled fluid-structure system of equations which models the hemodynamics in vessels. Application of the finite element method and semiimplicit time discretization leads to the discrete Oseen problem on every time step o...

A two-dimensional model for quasigeostrophic flow which exhibits an analogy with the three-dimensional incompressible Euler equations is considered. Numerical experiments show that this model develops sharp fronts without the need to explicitly incorporate any ageostrophic effect. Furthermore, these fronts appear to become singular in finite time. The numerical evidence for singular behavior su...

This paper is concerned with finding numerical solutions of a flow of ODE solutions. It describes a new method, based on Euler Backward method and interpolation, for finding solutions of autonomous problems. The special aspect is that this method is explicit, and resolves the flow with similar accuracy as Euler Backward method, even when the problem is stiff. An analysis is given of both stabil...

Direct numerical simulation of turbulent flow behind a cylinder, wake flow, using the random vortex method for an incompressible fluid in two dimensions is presented. In the random vortex method, the primary variable is vorticity of the flow field. After generation on the cylinder wall, it is followed in two fractional time step in a Lagrangian system of coordinates, namely convection and diffu...

The main objective of the present study is to utilize a novel linearization strategy to linearize the convection terms of the quasi-one-dimensional Euler governing equations on collocated grids and to examine its shock-capturing capabilities. To avoid a pressure checkerboard problem on the collocated grids, it is necessary to utilize two velocity definitions at each cell face. Similarly, we def...

A time-accurate, upwind, finite volume method for computing compressible flows on unstructured grids is presented. The method is second order accurate in space and time and yields high resolution in the presence of discontinuities. For efficiency, the Roe approximate Riemann solver with an entropy correction is employed. In the basic Euler/Navier-Stokes scheme, many concepts of high order upwin...

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...

The implementation of a 2D Euler solver on graphics hardware is described. The graphics processing unit is highly parallelised and uses a programming model that is well suited to flow computation. Results for a transonic turbine cascade test-case are presented. For large grids (10 nodes) a 40 times speed-up compared to a Fortran implementation on a contemporary CPU is observed.

Many important phenomena in nature are modeled by partial differential equations (PDEs). Such equations describe flow of air, water, oil and other substances and propagation of electromagnetic and sound waves in different media. Also, PDEs arise in many other application areas ranging from chemistry to economy. In the present paper, the focus is on computational fluid dynamics, CFD. Issues rega...