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Boundar condition for pipe flow

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Old   May 10, 2011, 05:28
Question Boundar condition for pipe flow
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I am beginner in CFD. I need some help, how to take into consideration the effect of the gravity in vertcial pipeflow (upward flow).

Thanks.
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Old   May 10, 2011, 07:07
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i guess u can easily set gravity in operating conditions
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Old   May 10, 2011, 08:04
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Yes that where i need help, do i check in gravity and make -9.8m2/s ... aldo do i need to check in operating density and what vale, I am simulating vertical pipe flow of water
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Old   May 11, 2011, 02:22
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it depends on ur coordinate system, if ur vertical axis goes up positiv, then jes -9.82 m/s˛ ..... and this density checkbox u can ignore for water in my opinion

hope i could help u
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Old   May 12, 2011, 00:12
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Thanks shimmyya for your reply. Yes my cooridnate system is +y upwars i.e. I have taken my reference coordinates (0,0,0) at the top of the pipe.
As I understand I do need to check in the gravity option box and do not need to fill the operating density ... but by default it shows a value of 1.225 .. shoud I make this zero or someother value as far i understood the value subsituted here will be subtracted from fluid density i.e. [rho(fluid) - rho(op density] g.h?

waiting for your reply. Thanks once again
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Old   May 12, 2011, 02:05
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hi,
just let this "specified operating density" box unchecked, that should be fine.
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Old   May 13, 2011, 02:23
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Need help, can you plz help ... how to calcuate the pressure drop in pipe flow ... can't seem 2 understand the Fluent output plots .. as values I have do not come anywhere near.
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Old   May 16, 2011, 09:44
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i dont know if this help u , but u can set probe-points which can read out the data of this points like pressure, velocity ......

could be also good to know what version of FLUENT u use
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