help in pressure drop calculation in fluent

sinaupdate · June 17, 2012, 08:32

hi everyone
i want to calculate the pressure drop of fluid along a pipe with anuular section ,in result i see that the pressure drop that fluent give me is 200 pa less than exact pressure drop that it must be..

what is the reason for that??
lenght = 12 ft D_out = 2.91 in D_in=1.8 in mesh 2,600,000
out let boundary = 0 pressure
inlet boundary= velocity inlet
fluid =water

for water inlet with velocity INLET 1.58 i receive 1100 pa/m pressure drop but it must be more.
tnx for any help

ghost82 · June 17, 2012, 09:39

Have you set roughness in wall boundaries?

sinaupdate · June 17, 2012, 17:52

hi
yes roughness constant as a default is 0.5
i dont know when i do it by one liquid, result is little lower and when i use liquid-solid, pressure drop it twice the exact result !!

Omish · July 10, 2016, 06:56

Quote:

Originally Posted by sinaupdate

hi
yes roughness constant as a default is 0.5
i dont know when i do it by one liquid, result is little lower and when i use liquid-solid, pressure drop it twice the exact result !!

Hi
Did find the solutin about this problem? I have the same problem. Please let me know if you have solved it.

June 17, 2012, 08:32	help in pressure drop calculation in fluent	#1
sinaupdate New Member sina Join Date: May 2012 Posts: 8 Rep Power: 14	hi everyone i want to calculate the pressure drop of fluid along a pipe with anuular section ,in result i see that the pressure drop that fluent give me is 200 pa less than exact pressure drop that it must be.. what is the reason for that?? lenght = 12 ft D_out = 2.91 in D_in=1.8 in mesh 2,600,000 out let boundary = 0 pressure inlet boundary= velocity inlet fluid =water for water inlet with velocity INLET 1.58 i receive 1100 pa/m pressure drop but it must be more. tnx for any help

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Pressure drop calculation and comparison to analytic solutions	n0name	STAR-CCM+	2	August 16, 2012 04:36
Pressure BC for combustion chamber	Giuki	FLUENT	1	July 19, 2011 12:35
pressure drop calculation multi-inlet-outlet syst.	timmyy	FLUENT	1	April 24, 2007 07:03
Pressure drop of valve with valve opening of 30%	elogesh	Main CFD Forum	2	January 5, 2007 13:30
pressure drop	Jerry Hug	Main CFD Forum	0	December 3, 2003 09:11

June 17, 2012, 09:39		#2
ghost82 Senior Member Rick Join Date: Oct 2010 Posts: 1,016 Rep Power: 27	Have you set roughness in wall boundaries?

June 17, 2012, 17:52		#3
sinaupdate New Member sina Join Date: May 2012 Posts: 8 Rep Power: 14	hi yes roughness constant as a default is 0.5 i dont know when i do it by one liquid, result is little lower and when i use liquid-solid, pressure drop it twice the exact result !!