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Old   November 26, 2019, 16:01
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Rafael
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Hello! I'm noob with CFX. I want to simulate the air flow inside a bus when the bus is at 30km/h. However, when the simulation is complete, I open the postprocessor and add streamlines of velocity, but looks like the air isn't coming inside the bus, just flowing outside.
This is my geometry
https://ibb.co/Nn6G3vn

This is the streamlines
https://ibb.co/x8jK349

This is my project with the geometry file
https://www.dropbox.com/s/lrtfi1u2s1...OTRAB.zip?dl=0



Thank you!
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Old   November 26, 2019, 17:44
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Glenn Horrocks
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Streamlines are integrated from a seed point. You appear to have put the seed points on your inlet, and not much of your flow from the inlet will get inside the bus. I would recommend putting some seed points inside the bus - as points, lines or volumes which you define inside the bus; then use that object as the streamline seed point.
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Old   November 26, 2019, 18:02
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I think I understood hahaha
So if I create domains in all windows and add streamlines starting from the windows? However I don't know how to add domains
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Old   November 26, 2019, 18:40
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Well, as I don't know how to see the streamlines starting from the windows (and have no idea of what to search) I'm just clicking every button I see.
Selecting "Default Domain Default" as the starting for the streamlines, I got this:
https://ibb.co/LgVTbT5
Could you explain me what means to select "default domain default" at the "starting from" option? I could say that select the inlet in this option gives me the streamlines starting from the inlet, but I can't understand when I select the "default domain default".
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Old   November 26, 2019, 22:42
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If you select a volume for your seed point (such as your domain as you have done) then it will use every node location in the volume as a seed point. But note that by default it then thins them down as there are usually zillions of nodes in a volume.

The easiest way to start a streamline exactly where you want it is to define a point using XYZ coordinates to be inside your bus. Then make a new streamline object using the point object as a seed point.

But the image you show is what I would expect - flow streaming past the bus on the outside and a chaotic flow inside.
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Old   November 28, 2019, 23:08
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I really appreciate your help, ghorrocks! I create two plans and with contours I set the plan and the variable velocity to see it! Thats exactly what I want, cause with this plans I can make a relation between velocity of the air and thermal sensation! Thank you!!
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