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## Oseen Equations (oseen + equation)
## Selected Abstracts## Two preconditioners for saddle point problems in fluid flows INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 4 2007A. C. de NietAbstract In this paper two preconditioners for the saddle point problem are analysed: one based on the augmented Lagrangian approach and another involving artificial compressibility. Eigenvalue analysis shows that with these preconditioners small condition numbers can be achieved for the preconditioned saddle point matrix. The preconditioners are compared with commonly used preconditioners from literature for the Stokes and Oseen equation and an ocean flow problem. The numerical results confirm the analysis: the preconditioners are a good alternative to existing ones in fluid flow problems. Copyright © 2006 John Wiley & Sons, Ltd. [source] ## A weighted Lq -approach to Oseen flow around a rotating body MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 5 2008R. FarwigAbstract We study time-periodic Oseen flows past a rotating body in ,3 proving weighted a priori estimates in Lq -spaces using Muckenhoupt weights. After a time-dependent change of coordinates the problem is reduced to a stationary Oseen equation with the additional terms (,,,,x),,,,,u and ,,,,,u in the equation of momentum where , denotes the angular velocity. Due to the asymmetry of Oseen flow and to describe its wake we use anisotropic Muckenhoupt weights, a weighted theory of Littlewood,Paley decomposition and of maximal operators as well as one-sided univariate weights, one-sided maximal operators and a new version of Jones' factorization theorem. Copyright © 2007 John Wiley & Sons, Ltd. [source] ## Oseen coupling method for the exterior flow. MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 17 2004Part II: Well-posedness analysisAbstract In this paper, we recall the Oseen coupling method for solving the exterior unsteady Navier,Stokes equations with the non-homogeneous boundary conditions. Moreover, we derive the coupling variational formulation of the Oseen coupling problem by using of the integral representations of the solution of the Oseen equations at an infinity domain. Finally, we provide some properties of the integral operators over the artificial boundary and the well-posedness of the coupling variational formulation. Copyright © 2004 John Wiley & Sons, Ltd. [source] ## First-order system least squares for the Oseen equations NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 7 2006Sang Dong KimAbstract Following earlier work for Stokes equations, a least squares functional is developed for two- and three-dimensional Oseen equations. By introducing a velocity flux variable and associated curl and trace equations, ellipticity is established in an appropriate product norm. The form of Oseen equations examined here is obtained by linearizing the incompressible Navier,Stokes equations. An algorithm is presented for approximately solving steady-state, incompressible Navier,Stokes equations with a nested iteration-Newton-FOSLS-AMG iterative scheme, which involves solving a sequence of Oseen equations. Some numerical results for Kovasznay flow are provided. Copyright © 2006 John Wiley & Sons, Ltd. [source] |