On 12/15/23 20:28, Smith Jack wrote:
At the right boundary, the Dirichlet boundary condition is applied: c_1(x = L, t) = c_{10},  c_2(x = L, t) = c_{20}.
At the left boundary, the flux of c_1, c_2 is set by:
*\partial c_1 / \partial x  (x = 0, t) = r_1(c_1, c_2)*
*\partial c_2 / \partial x  (x = 0, t) = r_2(c_1, c_2)*
Here, r1 r2 are reactions rates solved by an ODE solver. Then how to use such a boundary condition ? There is no analytic expression for r1 and r2. I can only get them numerically

This is a nonlinear problem. Make it simpler for conceptual reasons by assuming that you have only one species, c=c1 for the moment. Then if you write down the weak formulation of the equation, you will see where r(c)=r1(c1) appears in the weak form. This ends up being a situation not so different from what step-15 does, and it is solved with the same methods as step-15. (A better version of step-15 is step-77, but it is useful to start with step-15 if you want to understand the concepts.)

Best
 W.

--
------------------------------------------------------------------------
Wolfgang Bangerth          email:                 bange...@colostate.edu
                           www: http://www.math.colostate.edu/~bangerth/


--
The deal.II project is located at http://www.dealii.org/
For mailing list/forum options, see 
https://groups.google.com/d/forum/dealii?hl=en
--- You received this message because you are subscribed to the Google Groups "deal.II User Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to dealii+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/dealii/829055c9-7557-4309-8664-5403db0d882f%40colostate.edu.

Reply via email to