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Liouskos Jiannis October 18, 2001 12:10

pressure drop within a pipe
Hello everyone!

My case is: Upward flow of air, within a pipe.I have set the external pressure eq to 0(relative to 1.0e5)and inlet velocity 2m/s, but the results are not logical.i.e. -1.0E-7(pa) at the bottom and 3.0e-5 at the top. Is there any specific setting that i haven't do correctly? Looking forward to your help. Thank you!

leon October 18, 2001 21:43

Re: pressure drop within a pipe
Is your velocity field pointing in the correct direction ?

The pressure differential desribed seems to suggest that the flow is actual flowing down the pipe noy up it.

Try reversing the direction of the velocity of the air going up the pipe.

Habe you set the top of th pipe as an outlet / fixed pressure bouandary so that the air can flow out of the domain ? If not the air would tend to reverse diretion.

I hope this helps


David Glynn October 22, 2001 12:58

Re: pressure drop within a pipe
Leon's advice sounds good!

Are you sure it is fully converged?

By the way - is the density constant?


Liouskos Jiannis October 23, 2001 03:51

Re: pressure drop within a pipe
The direcrtion of the air flow is up-wards, there is an outlet at the top af the pipe and the pressure tis set to 0(RElaative to 1e+5). yes, the dencity is constant, but i still have the same problem. Is there somethin g i can do about it?

Thank you for your help

David Glynn November 6, 2001 09:00

Re: pressure drop within a pipe
You must have done something wrong!

Are you using VR?

If you set it up with VR, it's very simple - an inlet, and outlet, and plate(s) for wall friction. You can set it up in 5 minutes and it will work fine.

PattiMichelle February 6, 2002 13:04

Re: pressure drop within a pipe
Is bouyancy turned on? Is the value of the gravitational constant correct?

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