Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
Performance of Finite Volume Discretization Schemes in the Backward-Facing Step Problem - Part II: Numerical Error of Schemes
Submission Author:
Gustavo Silva Rodrigues , MG , Brazil
Co-Authors:
Gustavo Silva Rodrigues, Adyllyson Nascimento, José Ricardo Figueiredo
Presenter: Gustavo Silva Rodrigues
doi://10.26678/ABCM.COBEM2019.COB2019-0324
Abstract
The objective of this paper is to expand the investigation of numerical performance of six finite-volume discretization schemes, in the classic benchmarking problem of the two-dimensional backward-facing incompressible step flow. This test problem is governed by the Navier-Stokes and continuity equations, which are solved numerically using the formulation of primitive variables and the Poisson equation for the pressure in the semi-staggered mesh structure. This problem does not have an exact analytical solution for comparison with the numerical results, the Richardson extrapolation technique is used to estimate the exact solution and compare the accuracy of the schemes. This second part investigate the effects that the Reynolds number has on the acuracy of the discretization schemes through the recirculation lengths and the velocity fields. The schemes submitted to this test were the central differencing (CDS), simple exponential (EXP), first order upwind (FOU), second order upwind (SOU), QUICK and UNIFAES. The accuracy achieved by the CDS, QUICK, SOU and UNIFAES schemes when convergent is practically identical in terms of magnitude for low Reynolds numbers, however as the Reynolds number increases the errors of the schemes increase. In most cases UNIFAES presents the smallest errors, followed by SOU.
Keywords
backward-facing step flow, laminar flow, Discretization Schemes, Finite Volumes, Richardson extrapolation
