Diffusion into sphere from a well-stirred solution of limited volume

[t6g]

Hi David,

Do you have an input file to simulate diffusion into sphere from a well-stirred solution of limited volume? Something like Crank 1975 analytical solution as you mentioned in Example 13c in the manual.

If not, you may help me with the attached two input files. I try to simulate diffusion into a sphere following Example 13c. t1.phrq uses one mobile cell, but does not march forward in time. t2.phrq uses two mobile cells, but the concentration history differs in the two mobile cells, and the associated immobile cells. I thought that they should be identical. There are something that I do not understand.

If we have both stagnant zone and mobile zone, the mobile cell length needs to be fine enough such that the time step is sufficiently small so that the mixing factors are between 0 and 1, right?

Thanks.
Guoping Tang

 

[dlparkhurst]

Sorry, these mixes are not my strength. Tony Appelo is master.