Stokes Elements in 2-D: RT0-P0
We explain stable element RT0-P0 (the lowest order Raviart-Thomas element for velocity and piecewise constant for pressure) of Stokes equations in 2-D.
[u,p,w,edge,eqn,info] = StokesRT0(node,elem,bdFlag,pde,option)
See also PoissonRT0doc
Copyright (C) Long Chen. See COPYRIGHT.txt for details.
Contents
Data Structure
The data structure for RT0 element can be found at RT0 lowest order edge element in 2D.
For pressure, the basis is the chacteristic function of each triangle. So in the computation of divergence operator, elemSign should be used.
[node,elem] = squaremesh([0 1 0 1], 0.5); [elem,bdFlag] = sortelem(elem,bdFlag); [elem2edge,edge] = dofedge(elem);
Discretization
We discretize the following varational form of Stokes equation
------------------------------------------------------------------
(rot u,rot v) +(div u, div v) - (p, div v) = (f,v)
(- div u,q) = 0
u = g on boundary
------------------------------------------------------------------