Flow in a Channel with Sudden Expansion

Andrew Cliffe, University of Nottingham

Abstract: Numerical calculations of laminar flow in a two-dimensional channel with a sudden expansion exhibit a symmetry breaking bifurcation at Reynolds number 40.45 when the expansion ratio is 3:1. In the experiments reported by Fearn, Mullin and Cliffe (JFM, Vol 211, pp.595-608, 1990) there is a large perturbation to this bifurcation and the agreement with the numerical calculations is surprisingly poor. The talk will describe an attempt to explain this discrepancy using techniques from uncertainty quantification and Bayesian inverse methods.