Explicit and semi-implicit characteristic based split (CBS) schemes for viscoelastic flow calculations

Explicit and semi-implicit characteristic based split (CBS) schemes for viscoelastic flow calculations

Liu, C.B.
Nithiarasu, P.

2006-09-08

A fully explicit characteristic based split (CBS) based artificial compressibility (AC) method and a semi-implicit CBS scheme, for viscoelastic flow over a circular cylinder placed in a rectangular channel are presented in this paper. In the explicit form the pressure equation is solved explicitly by introducing an artificial compressibility parameter, while a pressure Poisson equation is implicitly solved in the semi-implicit form. Three different constitutive models have been employed to investigate flow past a circular cylinder. They are the Oldroyd-B, upper convected Maxwell (UCM) and simplified Phan-Thien/Tanner (PTT) models. The main difference from the previously published results is that in the present study the artificial dissipation is not switched on until it is absolutely essential. No loss of convergence to steady state was observed in any of the results presented in this paper. Comparison of the present numerical solution with other available numerical data shows that the CBS algorithm is in excellent agreement at lower Deborah numbers. However, at higher Deborah numbers, the present results differ substantially from other numerical results. The two presented schemes give almost identical drag force values and the solutions presented demonstrate that both schemes are suitable for viscoelastic flow calculations.

CBS scheme
artificial compressibility(AC)
semi-implicit
Oldroyd-B
Maxwell
PTT
viscoelastic flow

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Conference proceedings

conference paper

(c) 2006 Liu, C.B.; Nithiarasu, P.