Boundar condition for pipe flow

GamFlu · May 10, 2011, 06:28

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.

shimmyya · May 10, 2011, 08:07

i guess u can easily set gravity in operating conditions

GamFlu · May 10, 2011, 09:04

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

shimmyya · May 11, 2011, 03:22

it depends on ur coordinate system, if ur vertical axis goes up positiv, then jes -9.82 m/s² ..... and this density checkbox u can ignore for water in my opinion

hope i could help u

GamFlu · May 12, 2011, 01:12

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

shimmyya · May 12, 2011, 03:05

hi,
just let this "specified operating density" box unchecked, that should be fine.

GamFlu · May 13, 2011, 03:23

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.

shimmyya · May 16, 2011, 10:44

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

May 10, 2011, 06:28	Boundar condition for pipe flow	#1
GamFlu New Member Join Date: Mar 2011 Posts: 11 Rep Power: 15	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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May 10, 2011, 08:07		#2
shimmyya New Member eddy Join Date: Apr 2011 Posts: 8 Rep Power: 15	i guess u can easily set gravity in operating conditions

May 10, 2011, 09:04		#3
GamFlu New Member Join Date: Mar 2011 Posts: 11 Rep Power: 15	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

May 11, 2011, 03:22		#4
shimmyya New Member eddy Join Date: Apr 2011 Posts: 8 Rep Power: 15	it depends on ur coordinate system, if ur vertical axis goes up positiv, then jes -9.82 m/s² ..... and this density checkbox u can ignore for water in my opinion hope i could help u

May 12, 2011, 01:12		#5
GamFlu New Member Join Date: Mar 2011 Posts: 11 Rep Power: 15	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

May 12, 2011, 03:05		#6
shimmyya New Member eddy Join Date: Apr 2011 Posts: 8 Rep Power: 15	hi, just let this "specified operating density" box unchecked, that should be fine.

May 13, 2011, 03:23		#7
GamFlu New Member Join Date: Mar 2011 Posts: 11 Rep Power: 15	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.

May 16, 2011, 10:44		#8
shimmyya New Member eddy Join Date: Apr 2011 Posts: 8 Rep Power: 15	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