Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
defining output variable of an interface as dependent variable in global equation
Posted 14 mai 2013, 15:21 UTC−4 General Version 4.3a 0 Replies
Please login with a confirmed email address before reporting spam
I want to use the magnetic field density, B, calculated from the mf interface and plug it in an equation for the surface displacement, h:
h =- B^2 / (4*rho*g_const*mu)
However, I don't know how to specify that I only need the B values along a particular line (i.e. the free surface/top surface of the fluid). I tried defining a local variable, B_surf, along the boundary I am interested using the mf.Bz values (i.e. mf interface output variable,), hoping that it would give me a set of B values only along that boundary. I, then, used B_surf in my h equation instead of using mf.Bz.
The error message says: failed to evaluate variable B_surf
My equation might not be in the right format. I entered it in the ODE table as: h*4*rho*g_const*mu/ (- B_surf^2) to solve for h and then I entered h as the prescibed displacement in the ale interface.
Hello Diana David
Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.
If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.