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Gas velocity profile in laminar flow model

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Hi, I am simulating gas velocity and tempeature profile in a tube using laminar flow model. But I have some problems:
1. In "Heat flux" text field, "[1/cm]", why "cm" is devided by 1, rather than "cm" directly? Is "cm" the same with the unit that I defined for ractangle?
2. At this stage (see in the model), the mesh is set to extremely course, it works. However, when I choose normal mesh, it does not work at all. What's the problem? There only should be a diffrence of calculation time.
3. In this model, both pressure and temperature profiles are right, only the velocity profile does not look like that in our quartz tube. Is there any solutions?
4. Study 2 (time dependent) still does not work at this status.
Can anybody help me solve them? You can change some parameters in the attached model! Thanks a lot!


0 Replies Last Post 18 mars 2016, 12:31 UTC−4
COMSOL Moderator

Hello Erxiong Ding

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