How to change boundry contidion in CFX-pre

windfire · May 18, 2016, 22:10

hello,i have a confused problem about boundry condition ,i want to simulate water flow in pipelines, i want to make a roundess wall be seted as wall condition,and wall condition changed into inlet condition several seconds ,how to realize this in CFX-Pre,thank you !

ghorrocks · May 19, 2016, 06:31

I do not understand your question. But if you are asking how can you change a boundary condition type during a run - the simplest way is to stop the run, change the boundary condition to the new type and restart the run using the first run as an initial condition.

Steffen595 · May 19, 2016, 20:14

do you mean, while the simulation is running, i.e. transient? Then flow into one inlet stops (closed by valve) and another wall becomes an inlet (opened by valve) ? Maybe make 2 inlets and make the massflow time dependant? So one goes to 0 and the other from 0 to something?
No idea, if you can change something frim inlet boundary condition to wall.
If something is defined as inlet and later on something wants to flow out of the inlet, the solver will place a wall there and give you a warning. Not the nicest way to do things, but that would work.

May 18, 2016, 22:10	How to change boundry contidion in CFX-pre	#1
windfire New Member Ian Join Date: Oct 2013 Posts: 23 Rep Power: 12	hello,i have a confused problem about boundry condition ,i want to simulate water flow in pipelines, i want to make a roundess wall be seted as wall condition,and wall condition changed into inlet condition several seconds ,how to realize this in CFX-Pre,thank you !

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Only two turbulence options available in CFX Pre	Jack001	CFX	5	March 30, 2016 02:47
air ideal gas in CFX Pre	wangy1767	CFX	9	October 1, 2012 07:55
CFX Pre Domains for centrifugal pump	MechKim	CFX	1	September 24, 2012 08:06
Setting material properties - CFX Pre	cavani	CFX	6	January 27, 2011 19:52
Problems with adding two meshes together in CFX Pre	peterputer1	CFX	2	September 23, 2009 08:08

May 19, 2016, 06:31		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	I do not understand your question. But if you are asking how can you change a boundary condition type during a run - the simplest way is to stop the run, change the boundary condition to the new type and restart the run using the first run as an initial condition.

May 19, 2016, 20:14		#3
Steffen595 Senior Member Join Date: May 2012 Location: Melbourne Posts: 161 Rep Power: 13	do you mean, while the simulation is running, i.e. transient? Then flow into one inlet stops (closed by valve) and another wall becomes an inlet (opened by valve) ? Maybe make 2 inlets and make the massflow time dependant? So one goes to 0 and the other from 0 to something? No idea, if you can change something frim inlet boundary condition to wall. If something is defined as inlet and later on something wants to flow out of the inlet, the solver will place a wall there and give you a warning. Not the nicest way to do things, but that would work.