Re: Transient Diffusion with Time Varying BC

2013-05-13 Thread Chuck Holbert
Yes, now I see this.  So, maybe mathematically I have setup the problem incorrectly.  I would like to allow the concentrations at the interface to increase if the rate of back diffusion becomes greater than the rate of decay. The rate of decay at the interface is dc/dt = -kt. ___

Re: Transient Diffusion with Time Varying BC

2013-05-13 Thread Jonathan Guyer
On May 13, 2013, at 3:58 PM, Chuck Holbert wrote: > To estimate back diffusion and an accumulation at the interface (left-most > boundary), don't I want the precursor of the exponential to change at every > timestep as phi changes? > > Forgive me if this should be evident, but want to make su

Re: Transient Diffusion with Time Varying BC

2013-05-13 Thread Chuck Holbert
Jonathan - To estimate back diffusion and an accumulation at the interface (left-most boundary), don't I want the precursor of the exponential to change at every timestep as phi changes? Forgive me if this should be evident, but want to make sure I understand. Again, thank you for your assista

Re: how to implement a thermal contact between two regions ?

2013-05-13 Thread Jonathan Guyer
On May 10, 2013, at 2:11 AM, Frederic Durodie wrote: > could you help me with how to implement a thermal contact, hc > [W/(m^2.K)], between two regions : so there is like a discontinuity in > the temperature between the two regions. I don't know whether the following is the solution you want

Re: Transient Diffusion with Time Varying BC

2013-05-13 Thread Jonathan Guyer
On May 12, 2013, at 10:23 PM, Chuck Holbert wrote: > I'm looking for a bit of assistance in how to organize a FiPy script I am > trying to write. I am trying to model transient 1D diffusion into and out of > soil with an exponentially decaying boundary condition. I assuming a > starting con