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pulse laser model using the function flc2hs
Posted Sep 28, 2011, 2:57 a.m. EDT Heat Transfer & Phase Change Version 4.1 2 Replies
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Hi, everyone, I’m studying (totally a strange one) the COMSOL to model the pulse laser, I have searched some useful models and tips from this web, but when I try to build the model myself, it seem to a big challenge. One of the problems is about the function flc2hs.
The parameter in the function flc2hs (t-start point, the width of transition), the actual definition of the second term in the bracket, I just call it like this temporarily because it presents the slope/width of the transition. But the different value of the two parameters presents various photogram, just illustrated as follow:
When the function:
1. flc2hs(t-5e-1,1e-14)-flc2hs(t-8e-1,1e-14)
2. flc2hs(t-5e-2,1e-14)-flc2hs(t-8e-2,1e-14)
3. flc2hs(t-5e-9,1e-14)-flc2hs(t-8e-9,1e-14)
When the start point is becoming smaller, the pulse (the y data are 1) is less evident and finally disappear to present a horizontal line (all the y data are zero). How do I should do to obtain the pulse using this function?
Thanks to all in advance.
sorry it seems that i can't attach the photos.
The parameter in the function flc2hs (t-start point, the width of transition), the actual definition of the second term in the bracket, I just call it like this temporarily because it presents the slope/width of the transition. But the different value of the two parameters presents various photogram, just illustrated as follow:
When the function:
1. flc2hs(t-5e-1,1e-14)-flc2hs(t-8e-1,1e-14)
2. flc2hs(t-5e-2,1e-14)-flc2hs(t-8e-2,1e-14)
3. flc2hs(t-5e-9,1e-14)-flc2hs(t-8e-9,1e-14)
When the start point is becoming smaller, the pulse (the y data are 1) is less evident and finally disappear to present a horizontal line (all the y data are zero). How do I should do to obtain the pulse using this function?
Thanks to all in advance.
sorry it seems that i can't attach the photos.
2 Replies Last Post Oct 10, 2011, 11:15 a.m. EDT
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Posted:
1 decade ago
Hi
in V4 you have the functions predefined as step or pulse, and you can combine those, and plot them beforehand rapidly ;)
if you then solve in temporal, do not forget to use strict or intermediate time stepping with a time step that resolves with a few points each ramp region, otherwise the "automatic" stepping timer will most probably jump over your pulses
--
Good luck
Ivar
in V4 you have the functions predefined as step or pulse, and you can combine those, and plot them beforehand rapidly ;)
if you then solve in temporal, do not forget to use strict or intermediate time stepping with a time step that resolves with a few points each ramp region, otherwise the "automatic" stepping timer will most probably jump over your pulses
--
Good luck
Ivar
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Posted:
1 decade ago
thanks very much, I just plot it to test if it's right.