## Abstract

We devise and analyze a new local discontinuous Galerkin (LDG) method for the Stokes equations of incompressible fluid flow. This optimally convergent method is obtained by using an LDG method to discretize a vorticity-velocity formulation of the Stokes equations and by applying a new hybridization to the resulting discretization. One of the main features of the hybridized method is that it provides a globally divergence-free approximate velocity without having to construct globally divergence-free finite-dimensional spaces; only elementwise divergence-free basis functions are used. Another important feature is that it has significantly less degrees of freedom than all other LDG methods in the current literature; in particular, the approximation to the pressure is only defined on the faces of the elements. On the other hand, we show that, as expected, the condition number of the Schur-complement matrix for this approximate pressure is of order h ^{-2} in the mesh size h. Finally, we present numerical experiments that confirm the sharpness of our theoretical a priori error estimates.

Original language | English (US) |
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Pages (from-to) | 533-563 |

Number of pages | 31 |

Journal | Mathematics of Computation |

Volume | 75 |

Issue number | 254 |

DOIs | |

State | Published - Apr 2006 |

## Keywords

- Divergence-free elements
- Hybridized methods
- Local discontinuous Galerkin methods
- Stokes equations