I am trying to solve the advection equation (with advective velocity b=(0,-1)) on a domain that has been split in two subdomains. To split the domain, I’m using the code previously made available by Guosheng, see:
What I would like to do, is solve the advection equation on the whole domain. As initial test case I use as initial condition that u=1 and the inflow condition is 1 so that the solution must be 1 for the whole simulation. This is not happening. Instead, on half the domain the solution is equal to 1 and on the other half the solution eventually tends to u=0.5. I think this has to do with the call to u.Other() on the interface between the two subdomains. I attach my code. Do you have any suggestions how to fix this issue?