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Discrepency between 2D and 3D models of temperature rise in thin film
Posted Jul 18, 2011, 12:11 p.m. EDT Heat Transfer & Phase Change, Geometry Version 4.2 0 Replies
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My name is Carl Merrigan. I am an undergraduate summer REU student attempting to do some modeling in Comsol. I have no previsous modeling experience.
I am attempting to model the laser-induced temperature rise in a 100 nm thin film of vanadium dioxide on 1 mm thick glass substrate. I have created a 2D axisyemmetric model and a 3D model. The 2D axisymmetric model gives a maximum temperature of 340 C, while the 3D model gives a max temp of 301 C. In both models, I have defined a Gaussian heat sources that I believe should be equivalent. Any ideas about what could be causing this discrepancy?
Heat source for 2D axisymmetric Q = (1-R)*gamma*I0*exp(-(r/Rs)^2)*exp(-gamma*abs(z)) Units: W/m^3
Heat Source for 3D Q = (1-R)*gamma*IO*exp(-(x^2+y^2)/(Rs^2))*exp(-gamma*abs(z)) Units: W/m^3
The parameters in the above equations are: R- reflection coefficient, gamma- absorbtion coefficient, Rs is the radius of the beam spot = 100 micrometers, and I0 is the maximum intensity.
I can provide more details about the way I have defined both geometries if needed. I think I am defining them equivalently, but I'm not sure.
Hello Carl Merrigan
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