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...

This research describes the unsteady two-dimensional reacting flows around a circular cylinder. The numerical solution combines the random vortex method for incompressible two-dimensional viscous fluid flow with a Simple Line Interface Calculation (SLIC) algorithm for the propagation of flame interface. To simplify the governing equations, two fundamental assumptions namely Low Mach Number and ...

We present numerical comparisons for the simulation of unsteady 2D shallow water flows over topography with wet/dry fronts, between well-balanced cell-centered and node-centered formulations of a finite volume high-resolution algorithm. In both formulations we utilize Roe’s Riemann solver, while second-order spatial accuracy is achieved with MUSCL-type reconstruction techniques. Grid refinement...

Street canyon flow regimes are classified using the time-averaged mean flow. The present paper discusses recent work on the dynamics of street canyon flows (important for pollutant transport) and the interaction with the shear layer and atmospheric boundary layer above, with a view to classifying the different regimes in terms of the unsteady characteristics of the flow for different types of c...

Introduction: In the first part of this talk, we present an algorithm for the numerical treatment of twopressure, two velocity continuum models for heterogeneous, immiscible mixtures [1]. This algorithm has been employed in a numerical study of unsteady shear flows of fluid-saturated granular materials, as predicted by the continuum model of [2]. A representative sample of these results are pre...

General second-order, variable-density, three-step and four-step projection methods are developed to simulate unsteady incompressible interfacial flows. A high-accuracy, variabledensity RKCN projection method is presented, in which the three-stage, low-storage RungeKutta technique and second-order semi-implicit Crank-Nicholson technique are employed to temporally update the convective and diffu...

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 ...

A method for performing anisotropic unstructured mesh adaptation is discussed that is well suited for computational fluid dynamics on parallel distributed memory computers. This algorithm which involves mesh motion, rather than refinement and coarsening, is fast, parallel, and fully conservative. The approach is effective at accurately capturing free-surface flows, boundary layers, and unsteady...

We present a reformulation of unsteady turbulent flow simulations. The initial condition is relaxed and information is allowed to propagate both forward and backward in time. Simulations of chaotic dynamical systems with this reformulation can be proven to be well-conditioned time domain boundary value problems. The reformulation can enable scalable parallel-in-time simulation of turbulent flows.

In many applications the flow that past bluff bodies has frequency nature (oscillated) and it is not uniform. This kind of flow has effects on the formation of vortex shedding behind bluff bodies. In this paper the flow around a circular cylinder was numerically simulated. The effects of frequency variation at inlet flow on the vortex shedding frequency were investigated. The transient Two-Dime...