| Author | Message | ||
     Francesca Rossi (francesca) New member Username: francesca Post Number: 1 Registered: 12-2003 |
I am using FlexPDE Student to study the case of heating biomaterials with lasers. I modeled the system as two concentric biomaterial cilinders: the inner one is the tissue directly heated by the laser. I supposed that from the inner cilinder there is heat convection towards the outer cilinder and towards the air (supposed to be at the top surface of the cilinder). As the cilinder is heated, I suppose that the ambient temperature stays stable (20°C), but I think that the outer cilinder temperature will not. So I imposed the natural boundary condition on top surface ad proportional to temp-20 (if temp is the temperature variable), but I don't know how to model the boundary condition on the separation surface of the two cilinder. Can you help me? Thank you Francesca Rossi | ||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 76 Registered: 06-2003 |
The default boundary condition on interior boundaries is "flux conservation". (Here "flux" is as defined in the documentation of "Natural Boundary Conditions". In a heat equation it is heat flux.) This means that in most cases it is not necessary to specify a boundary condition at interior interfaces. A Natural BC on an interior boundary defines the difference between opposing fluxes - ergo, a line (or surface) source or sink. |