Hi all, I am trying to implement a reduced order time dependent pressure boundary condition in nektar++. There is some work around this in the original nektar code by Leopold Grinberg on RC boundary conditions for vascular flows, (I haven't had any success any finding the code for this) However, I would like to couple the boundary condition with the backflow divergence boundary condition of S. Dong, the "Houtflow" condition that already exists. I have gotten as far as being able to hard code some things in Extrapolate.cpp to test that I can get a calculation for second order BFD, but I am confused/unsure about. 1.) best way to get variables from the xml file into extrapolate.cpp? 2.) best way to deal with the time dependency since time dependent boundaries are treated differently than constant values? 3.) where to add the additional pressure forcing term in the evaluation of the "Houtflow" condition code? Regards, ~Kurt -- Kurt Sansom