What depth does fluent use in 2D problems?

thanos · December 12, 2009, 10:01

Hello engineers,
I try to simulate the flow in a duct. As inlet boundary condition i choose the velocity inlet and as outlet the outflow. When i take the solution the mass flow result differs from this that i calculate with my pencil. I found out that in 2D problems fluent in order to calculate the mass flow rate regards the 2D geometry as a plate 1m deep. However, i want to have a cylindrical duct simulated and not a quadrangular one!
What can i do to change this option? I have not find a solution to this yet.
Thank you in advance!

coglione · December 14, 2009, 04:05

Hi Thanos,

for axisymmetric problems ( i guess your pipe is so) use the axi-symmetrical solver in Fluent. Using the cartesian 2-D solver will give incorrect results independant of the depth defined.

cheers

thanos · December 14, 2009, 04:14

Hello coglione!

Actually, my problem is not axisymetric. It is a T-junction of two ducts. is there any option to help me or i have to run a 3-D simulation for sure?

With respect

herntan · January 11, 2010, 03:24

Thanos,

I think u need to run it 3D.
2D simulation will give u the depth of 1 unit of the unit u use. If u use meter, u get 1 meter depth. even worst is, its not representing round.

I guess doing 3D won't take u alot of time. unless ur flow is very complex.

December 12, 2009, 10:01	What depth does fluent use in 2D problems?	#1
thanos Member thanos Join Date: Oct 2009 Posts: 30 Rep Power: 16	Hello engineers, I try to simulate the flow in a duct. As inlet boundary condition i choose the velocity inlet and as outlet the outflow. When i take the solution the mass flow result differs from this that i calculate with my pencil. I found out that in 2D problems fluent in order to calculate the mass flow rate regards the 2D geometry as a plate 1m deep. However, i want to have a cylindrical duct simulated and not a quadrangular one! What can i do to change this option? I have not find a solution to this yet. Thank you in advance!

January 11, 2010, 03:24		#4
herntan Senior Member YH Tan Join Date: Mar 2009 Location: Malaysia Posts: 119 Rep Power: 17	Thanos, I think u need to run it 3D. 2D simulation will give u the depth of 1 unit of the unit u use. If u use meter, u get 1 meter depth. even worst is, its not representing round. I guess doing 3D won't take u alot of time. unless ur flow is very complex. __________________ Herntan, Add Reputation if I am right

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Two questions on Fluent UDF	Steven	Fluent UDF and Scheme Programming	7	March 23, 2018 03:22
Fluent Convergence Problems	Vidya	FLUENT	24	January 1, 2016 13:01
Fluent connection with simulink by TCP/IP	Tanktruck	Fluent UDF and Scheme Programming	1	June 28, 2009 12:56
Problems with the UDF in Fluent	Mathew	FLUENT	1	February 26, 2008 19:15
Problems with Fluent	Jacek	Main CFD Forum	2	August 16, 2002 04:14

December 14, 2009, 04:05		#2
coglione Senior Member Max Join Date: Mar 2009 Posts: 133 Rep Power: 17	Hi Thanos, for axisymmetric problems ( i guess your pipe is so) use the axi-symmetrical solver in Fluent. Using the cartesian 2-D solver will give incorrect results independant of the depth defined. cheers

December 14, 2009, 04:14		#3
thanos Member thanos Join Date: Oct 2009 Posts: 30 Rep Power: 16	Hello coglione! Actually, my problem is not axisymetric. It is a T-junction of two ducts. is there any option to help me or i have to run a 3-D simulation for sure? With respect