Boundary conditions

SimoneTecnoil · December 17, 2009, 12:01

Hi to all....i have a problem!! I have water flowing in a pipe with several changes of section. The water has a pressure of 10 bar and a flow rate of 2kg/s in the input section. I do not understand how to set both of these data in the boundary conditions. Can you help me?

Maxtor · December 18, 2009, 07:54

Questions this fundamental on the use of any CFD code are best resolved by taking the appropriate training course.

Irshad22 · December 19, 2009, 11:44

Hello,
go to the zones i.e. third option of operation in Gambit. There you can go for assigining of boundary types not the values. Values will be given in Fluent. For reference Go through the tutorials provided by fluent.

bob12 · December 20, 2009, 09:30

ciao simone
per le condizioni al contorno le devi specificare in Gambit o il software per la mesh. Poi in Fluent puoi modificare sia la condizione al contorno che impostare i valori specifici per la soluzione del problema a secondo del modello.

SimoneTecnoil · December 22, 2009, 03:34

Ok .... I'll try to explain better! I have no problems in general in setting the boundary conditions ....I have to calculate the pressure drop in a nozzle. I know the incoming water pressure, its temperature and flow rate. I want to know the speed in output and especially the loss of pressure in the nozzle when the inlet pressure is 10 bar. Now ... I'm confusing between operating conditions and boundary conditions. I do not know the exit pressure .... but I would use "pressure outlet" on the output section because I know that is more accurate ... and what I put as "gauge pressure" in the outlet? I do not know! Input I want to use "mass flow inlet" and here there are no problems. But the pressure of 10 bar where you put it? In operating conditions? HELP

December 17, 2009, 12:01	Boundary conditions	#1
SimoneTecnoil New Member Join Date: Nov 2009 Posts: 8 Rep Power: 16	Hi to all....i have a problem!! I have water flowing in a pipe with several changes of section. The water has a pressure of 10 bar and a flow rate of 2kg/s in the input section. I do not understand how to set both of these data in the boundary conditions. Can you help me?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Impinging Jet Boundary Conditions	Anindya	Main CFD Forum	25	February 27, 2016 12:58
symmetry boundary conditions in cfx	lost.identity	CFX	41	May 22, 2013 07:21
Problems with boundary conditions for a lowRekOmegaSST turbulence model	cfdmarkus	OpenFOAM Running, Solving & CFD	16	November 14, 2011 04:44
Pressure boundary conditions	Lionel S.	Main CFD Forum	1	August 24, 2007 18:03
[Commercial meshers] Trimmed cell and embedded refinement mesh conversion issues	michele	OpenFOAM Meshing & Mesh Conversion	2	July 15, 2005 04:15

December 18, 2009, 07:54		#2
Maxtor New Member Peter Watson Join Date: Dec 2009 Posts: 1 Rep Power: 0	Questions this fundamental on the use of any CFD code are best resolved by taking the appropriate training course.

December 19, 2009, 11:44		#3
Irshad22 New Member Irshad Join Date: Dec 2009 Location: Bangalore Posts: 19 Rep Power: 16	Hello, go to the zones i.e. third option of operation in Gambit. There you can go for assigining of boundary types not the values. Values will be given in Fluent. For reference Go through the tutorials provided by fluent.

December 20, 2009, 09:30		#4
bob12 Member Join Date: Oct 2009 Location: Italy Posts: 88 Rep Power: 16	ciao simone per le condizioni al contorno le devi specificare in Gambit o il software per la mesh. Poi in Fluent puoi modificare sia la condizione al contorno che impostare i valori specifici per la soluzione del problema a secondo del modello.

December 22, 2009, 03:34		#5
SimoneTecnoil New Member Join Date: Nov 2009 Posts: 8 Rep Power: 16	Ok .... I'll try to explain better! I have no problems in general in setting the boundary conditions ....I have to calculate the pressure drop in a nozzle. I know the incoming water pressure, its temperature and flow rate. I want to know the speed in output and especially the loss of pressure in the nozzle when the inlet pressure is 10 bar. Now ... I'm confusing between operating conditions and boundary conditions. I do not know the exit pressure .... but I would use "pressure outlet" on the output section because I know that is more accurate ... and what I put as "gauge pressure" in the outlet? I do not know! Input I want to use "mass flow inlet" and here there are no problems. But the pressure of 10 bar where you put it? In operating conditions? HELP