| Author | Message | |||
     erez naaman (erez) New member Username: erez Post Number: 1 Registered: 10-2009 |
I'm trying to solve the problem of a laser cutting into metal. It's a chunk of metal that encounters a high energy laser beam from above moving at a constant speed. I have set the problem to the best of my understanding but have encountered a number of problems: 1. beta (the azimuth angle) seems to be almost random (it should be 0 everywhere except inside the cut). 2. the laser spot doesn't seem very round and so the cut seems to vary in width (which should be practically constant). right now the beam spot size is set to 100 micron but I sometimes use 500 micron as well. I have a feeling that beta is the main problem and it results in driving everything else crazy  I tried to play around with the threshold values but it didn't seem to help very much. Thanks in advance
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| Marek Nelson (mgnelson) Moderator Username: mgnelson Post Number: 151 Registered: 07-2007 |
You have posted the graphic file (*.pg5) and it shows that beta is zero everywhere. You should post the script file (*.pde) so that I can run it and see how you have posed the problem. | |||
| erez naaman (erez) New member Username: erez Post Number: 2 Registered: 10-2009 |
oops thanks
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| Marek Nelson (mgnelson) Moderator Username: mgnelson Post Number: 152 Registered: 07-2007 |
1) Yes, your values of beta look like noise and if you look at the value of your "depth" variable, you may see why. You are computing the value of beta as ARCTAN(dy(depth)/(dx(depth)+eps))-beta0 but the depth variable has no x or y variation (it is zero everywhere) so you are getting the arctan of roundoff error. I assume there is something amiss in the depth variable. Once you get variation in the depth variable, this may work as you hoped. 2) I think you are seeing the effect of too few mesh cells. The automatic mesh refinement wants to create more cells at the laser spot but is limited by the student version node limit. If you take a PLOT GRID(x,y) you will see that the mesh density is still a bit crude around the laser spot. |
the file