On pressure separation algorithms (PSepA) for improving the accuracy of incompressible flow simulations

• Published in: International journal for numerical methods in fluids 2009-02, Vol.59 (4), p.387-403
• Main Authors: Turek, S., Ouazzi, A., Hron, J.
• Format: Article
• Language: English
• Subjects: Computational methods in fluid dynamics; driven cavity; edge-oriented stabilization; Exact sciences and technology; finite elements; Fluid dynamics; Fundamental areas of phenomenology (including applications); incompressible Navier-Stokes equations; multiphase; Physics; pressure separation
• ISSN: 0271-2091; 1097-0363
• DOI: 10.1002/fld.1820

We investigate a special technique called ‘pressure separation algorithm’ (PSepA) (see Applied Mathematics and Computation 2005; 165:275–290 for an introduction) that is able to significantly improve the accuracy of incompressible flow simulations for problems with large pressure gradients. In our numerical studies with the computational fluid dynamics package FEATFLOW (www.featflow.de), we mainly focus on low‐order Stokes elements with nonconforming finite element approximations for the velocity and piecewise constant pressure functions. However, preliminary numerical tests show that this advantageous behavior can also be obtained for higher‐order discretizations, for instance, with Q2/P1 finite elements. We analyze the application of this simple, but very efficient, algorithm to several stationary and nonstationary benchmark configurations in 2D and 3D (driven cavity and flow around obstacles), and we also demonstrate its effect to spurious velocities in multiphase flow simulations (‘static bubble’ configuration) if combined with edge‐oriented, resp., interior penalty finite element method stabilization techniques. Copyright © 2008 John Wiley & Sons, Ltd.