Discussion Forum

Hi,

I would like to simulate a sea level increase as boundary condition. Initially, I simulated the problem with a constant pressure in order to have the initial condition. To this end, I defined the prescribed pressure at the seaside boundary as Variable, pressure_sea= p0+rhosg_const(H-y) with p0=0, H=1000 and rhos=1025 (defined as parameters). This boundary condition depends on the model height H. Thus, the pressure of the seaside boundary at the top of the model (node with y=1000) is pressure_sea=0, and at the bottom (y=0) is pressure_sea=0+10259.811000. The model run without any problem and I have the initial conditions for the model with time dependent BC. Now, in order to simulate the decrease or increase of the sealevel, I have defined a new variable which is time dependent, so instead of H=1000, I define the variable coast as 200cos((2pit[d]/6000[d])+pi), which changes from 1000 to 600m with a period of 6000d days. And the new expression (variable) for the boundary would be ptide=p0+rhosg_const(coast-y). I would like also to prescribe the pressure only if the value of y at the node is lower than coast which is f(t), and if y>coast I do not want to prescribe the pressure (I am not sure if this is possible). So I write the following expression as boundary condition pressure if(y<coast,ptide,p). For the transport problem I have defined an open boundary condition, so it there is inflow the concentration is equal to the one for the saltwater. But the model is not simulating the time dependent change in pressure and I do not know why. Thank you in advance Maria