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the static pressure at one outlet is negative?

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Old   August 15, 2013, 03:04
Default the static pressure at one outlet is negative?
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Rong Yue
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Hi, my friends, I simulated the pressure distribution in a geometry with pushed air in it. But I got a negative pressure at one outlet. That means the static pressure at this outlet is lower than the static pressure at reference point (101325 Pa). But I guess the pressure at this outlet should be higher than 101325. Because air is pushed from the bottom to the top of the geometry. Maybe the inlet is too close to the outlet. Then I extended the outlet to 5 times of the distance from the original position. And the static pressure are positive .But the mass flow rate at this outlet is positive, which is different with other two outlets.
My questions are: 1. why is the mass flow rate is positive at this outlet? 2. Is the pressure at the original outlet reliable after I extended it to a far distance?

I am so forwarding to your help! Thanks so so much!

Regards,

Rong

The original geometry is like this: Attachment 24418
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Old   August 15, 2013, 03:06
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the original geometry
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File Type: jpg ICEM mesh file 3.jpg (91.4 KB, 9 views)
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Old   August 15, 2013, 03:07
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the static pressure at inlet and outlets
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File Type: jpg static pressure at inlet and outlets.jpg (15.0 KB, 8 views)
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Old   August 15, 2013, 03:09
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the geometry after extended outlets
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File Type: jpg QQ图片20130815040823.jpg (26.7 KB, 8 views)
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Old   August 15, 2013, 03:12
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the mass flow rate at inlets and outlets after extended the outlets
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File Type: jpg massflow rate at inlet and outlets after extended.jpg (18.1 KB, 3 views)
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Old   August 15, 2013, 03:14
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the static pressure at inlets and outlets after extended outlets
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File Type: jpg static pressure at inlet and outlets after extended.jpg (20.1 KB, 2 views)
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Old   August 15, 2013, 03:15
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the mass flow rate at inlets and outlets in the original geometry
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File Type: jpg massflow rate at inlet and outlets.jpg (12.2 KB, 3 views)
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Old   August 15, 2013, 21:01
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Does anybody understand my problem? Please! Thanks a lot!
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