Dear Anne-Cecile This is just a way to implement a homogeneous BC on p. If you know that p has to be 0 at the top boundary (T_RG) you can use a reduced fem to remove the corresponding degrees of freedom. It is the simplest way to implement homogeneous Dirichlet BCs.
BR Kostas On Wed, Nov 10, 2021 at 1:05 AM Lesage,Anne Cecile J < ajles...@mdanderson.org> wrote: > Dear all > > > > Why shall I use a reduced fem for the pressure to solve the biot equations? > > > > mfp_ = gf.MeshFem(mesh, 1) > > mfp_.set_classical_fem(press_fem_order) > > keptdofs = np.arange(mfp_.nbdof()) > > keptdofs = np.setdiff1d(keptdofs, mfp_.basic_dof_on_region(T_RG)) > > mfp = gf.MeshFem("partial", mfp_, keptdofs) > > > > ……………………. > > > > #Equation 1 > > md.add_linear_term(mim9, > 'G*Grad(u):Grad(Test_u)+G/(1-2*nu)*Div(u)*Div(Test_u)+alpha*Grad(p).Test_u') > > > > #Equation 2 > > md.add_linear_term(mim4, > 'alpha/dt*(Div(u)-Div(u_prev))*Test_p+k*Grad(p).Grad(Test_p)') > > > > Thank you > > Regards > > Anne-Cecile > > > > > > > > > The information contained in this e-mail message may be privileged, > confidential, and/or protected from disclosure. This e-mail message may > contain protected health information (PHI); dissemination of PHI should > comply with applicable federal and state laws. If you are not the intended > recipient, or an authorized representative of the intended recipient, any > further review, disclosure, use, dissemination, distribution, or copying of > this message or any attachment (or the information contained therein) is > strictly prohibited. If you think that you have received this e-mail > message in error, please notify the sender by return e-mail and delete all > references to it and its contents from your systems. >