Numerical study of three recirculation zones in the unilateral sudden expansion flow

• Published in: International communications in heat and mass transfer Vol. 35; no. 9; pp. 1053 - 1060
• Main Authors: Lima, R.C., Andrade, C.R., Zaparoli, E.L.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 01.11.2008; Elsevier
• Subjects: Backward-facing step; CFD; Computational methods in fluid dynamics; Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Fundamental areas of phenomenology (including applications); Laminar flow; Physics; Reverse flow; Sudden expansion; CFD; Laminar flow; Reverse flow; Sudden expansion; Backward-facing step; Finite element method; Pipe flow; Computational fluid dynamics; Recirculating flow; Digital simulation; Computation code; Modelling; Step; Sudden enlargement; Finite volume methods
• ISSN: 0735-1933; 1879-0178
• DOI: 10.1016/j.icheatmasstransfer.2008.07.004

Numerical simulations of the two-dimensional laminar flow over a backward-facing step channel using two commercially-available Computational Fluid Dynamics (CFD) code are reported. The subject is to analyze the three recirculation regions of the flow in a unilateral sudden expansion. Results are presented for laminar air flow for Reynolds number lower than 2500. The mathematical model equations (mass conservation and momentum) were solved with finite element (FEM) and finite volume (FVM) methods and a segregated approach. To get the grid independent, intensive refinement studies were carried out. Results obtained are compared to experimental data presenting a good agreement. The numerical results of this work show a non-linear increase of the reattachment length as also shown by the experimental results extracted from literature.