Apologies for what is probably a fairly basic question:
I am solving laminar flow and also a Domain ODE. I want to use the T_stressy variable from the laminar flow solution as a source term in the ODE. I can use 'p', 'u', 'v', 'w' etc as source term no problem. I can also use comp1.spf.U but I cant use spf.T_stressy which is the variable I need. When I enter the equation in the text box the text is black, units accepted ok. Just when I run the analysis I get an error message saying Undefined variable - Variable: comp1.spf.T_stressy. What do I need to do to get the Domain ODE to accept the spf variable?
I am trying to use the drag force from a previous time step in my calculation. I understand I need to set up the ODE so I can use the prev command? All seems rather overcomplex to me as a new comsol user.