P1+P0 for pressure

Dear all,

I’m trying to implement an augmented Taylor-Hood method for mixed problems with a discontinuous pression finite element of the type P1+P0 (and not P1dc).
That anyone have a clue? I tried fespace Vh(Th, P1+P0) in vain.
Actually, P2b/P1dc generates too many degrees of freedom and for that reason I need to work with P2/P1+P0

Thanks!

Hi Amina
Can you provide a minimal working example, so that we can have a look at that make some suggestions to you.
IA

Actually my concern is only avout space declaring.
For Taylor-Hood in 2D we declare
Vh(Th,[P2,P2])
Ph(Th,P1)
and I just wanted to relace the P1 space by P1+P0, which doesn’t work. Hence, I was wondering if it is possible to do so differently. Actually, my space is the P1 space with addition of a constant to each cell (it is not the P1dc)

Best,
Amina.

Are you looking for P1 bubble finite element space ?
By the way, you can not use this FE space for pressure in order to the respect of the inf-sup condition

Hello Simon,
Thanks. I’m not looking for P1 bubble because the bubble is H1-conform, I’m looking for P1 with an additional constant onevery celle so that the pressure can be discontinuous. I don’t want to use P1dc because it ony works with P2b which generates much more degrees of freedom.
Best,
Amina.