Stabilisation Techniques for Viscoelastic Flows

In a comparative study, three di erent procedures of stabilisation techniques are considered for incompressible viscoelastic ow. The standard benchmark of ow past a sphere falling in a cylindrical vessel is employed to test these stabilisation techniques. First, discontinuity capturing (for stress) has been employed to investigate stabilisation properties. Then, the Zienkiewicz Zhu (ZPR-Q) quadratic patch recovery (for velocity gradients) is analysed and compared with a direct recovery technique. Finally, a third procedure is based on strain-rate stabilisation (for momentum). Results demonstrate that discontinuity capturing itself yields reasonable stabilisation properties, and quadratic patch recovery improves the solution somewhat over the linear version, but is not as stable as direct averaging. Strain-rate stabilisation also provides enhanced stabilisation properties comparable to those of discontinuity capturing. Computer Science Dept., Swansea Civil Eng. Dept., Swansea Computer Science Dept., Swansea