Effect of a high-resolution differencing scheme on finite-volume predictions of viscoelastic flows

Improved accuracy and enhanced convergence rate are achieved when a finite-volume method (FVM) is used in conjunction with a high-resolution scheme (MINMOD) to represent the stress derivatives in the constitutive equation, because it avoids oscillations of the solution field near sharp stress gradients. Calculations for the benchmark flow of an upper-convected Maxwell fluid through a 4:1 plane contraction were carried out at a constant Reynolds number of 0.01 and varying Deborah numbers in four consistently refined meshes, the finest of which had a normalised cell size of 0.005 in the vicinity of the re-entrant corner. The MINMOD scheme was able to provide converged solutions up to Deborah numbers well beyond those attained by other second-order accurate schemes. The asymptotic behaviour of velocity and stresses near the re-entrant corner was accurately predicted as compared with Hinch's theory [1]. The simulations improved previous results for the same flow conditions obtained with less accurate schemes, and the present results can be used as benchmark values up to a Deborah value of 3 with quantified numerical uncertainties. (C) 2000 Elsevier Science B.V. All rights reserved.