Some remarks on residual-based stabilisation of inf-sup stable discretisations of the generalised Oseen problem. (English) Zbl 1245.76051
Summary: We consider residual-based stabilised finite element methods for the generalised Oseen problem. The unique solvability based on a modified stability condition and an error estimate are proved for inf-sup stable discretisations of velocity and pressure. The analysis highlights the role of an additional stabilisation of incompressibility constraint. It turns out that the stabilisation terms of streamline-diffusion (SUPG) type play a less important role. In particular, there exists a conditional stability problem of the SUPG stabilisation if two relevant problem parameters tend to zero. The analysis extends a recent result [T. Gelhard et al., J. Comput. Appl. Math. 177, No. 2, 243–267 (2005; Zbl 1063.76054)] to general shape-regular meshes and to discontinuous pressure interpolation. Some numerical observations support the theoretical results.
MSC:
76M10 | Finite element methods applied to problems in fluid mechanics |
76D07 | Stokes and related (Oseen, etc.) flows |
65M60 | Finite element, Rayleigh-Ritz and Galerkin methods for initial value and initial-boundary value problems involving PDEs |
65N15 | Error bounds for boundary value problems involving PDEs |