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Modeling as heat source (Q) a supergaussian diode laser beam profile for studying heat transfer and structural stress in a cylindrical crystal rod.
Posted Apr 5, 2012, 3:28 p.m. EDT Heat Transfer & Phase Change, Modeling Tools & Definitions, Parameters, Variables, & Functions, Structural Mechanics Version 4.2a 1 Reply
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My intention is to determine the thermal distribution and stress distribution inside a yttrium aluminum garnet crystal (Material included in the Material Browser) in order to calculate in a second step the thermal lensing effect in the laser rod. (This is a particular optical effect that must be taken in account when designing solid-state lasers).
So far I have been able to create the geometry, assign the material information and I understand more or less the basic functions among the boundaries condition. I noticed that as heat source it is possible only a linear thermal implementation. How can I implement a Q(x,y,z) ( following the labels in the heat equation) definition that cover the supergaussian profile of the laser beam incident on the end-face of the cyulidrical rod? Anybody as a clue on this? Should I use the Mathematics option and throw in a Helmotz Equation or something? Anybody got some similar model to analyze? Thanks a lot to all.
Mich
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The physics behind is rather simple. A cylindrical rod of yttrium aluminum garnet is illuminated by a focused diode laser beam on one of the two circular end surfaces. At the moment I want to simplify the conditions, so I will model it with an Analytic Function defined below. The rod is interested by mainly 2 effects: a thermal gradient formation in radial direction and a strain given by the thermal mechanical stress. The volumetric heat load would be:
(A/(wx*wy))*exp(-2*(abs(x/wx))^2-2*(abs(y/wy))^2-tau*z)
where A, wx, wy, tau are parameters that I want to be able to control afterwards to see the change of the thermal gradient and the stain due to the thermal stress.
As first point I constructed a work plane with a rectangle and I builded the revolved rod. Now in Definitions I am countering "dummie user" problem and I do not know how to define the function properly and then how to couple this function to the heat transfer physics node where I suppose I should add the heat load.
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Mich