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Writing time and space related initial/boundary condition in COMSOL

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Hello,
I am modeling one-dimensional diffusion (in z-direction) of a substance from a film (block geometry with dimensions 0.035*0.035*0.0003). My initial and boundary conditions are

c = c0, t= 0, -h/2<z<h/2
c = 0, t>0, z= ±h/2

where,
c= conc. of the substance
c0= initial conc. of the substance
h = film thickness


I attempted to define these conditions using Boolean expression for the concentration, c, and c0=10 mol/m^3 in COMSOL as follows:

(10)*(t<0)*(-0.00015<z<0.00015) + (0)*(0<t<14400)*(z=-0.00015)*(z=0.00015) [mol/m^3]

The Boolean expression worked for the time variable alone but gave an error message when I included the space co-ordinate z.


How do I write these conditions in COMSOL?

Thank you.
Minal

0 Replies Last Post 30.05.2012, 16:07 GMT-4
COMSOL Moderator

Hello Minal Lalpuria

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