CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > CFX

Burst open of Diaphragm Valve.

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   May 23, 2010, 21:30
Unhappy Burst open of Diaphragm Valve.
  #1
New Member
 
jitukrjain
Join Date: Mar 2009
Posts: 6
Rep Power: 8
jitukr is on a distinguished road
I want to simulate a diaphragm valve in a pipe. Diaphragm of valve is required to burst after certain pressure and allow flow of fluid. Here what I guess, that remedy is that upto certain pressure diaphragm is wall and after certain higher pressure it has to become opening, how do I make this happen it Ansys-Cfx transient simulation in Ansys 11 or 12. Is their any other way out also? My thesis is stuck because of this problem.
jitukr is offline   Reply With Quote

Old   May 24, 2010, 06:45
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,929
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
You have not explained why you intend to do the simulation. What results are you looking for? Do you want details of the fracture process? Or just the shock wave which comes out of it? Do you care about the compression process before the rupture? I assume you are talking about a shock tube diaphragm, so are talking about high Ma flows.
ghorrocks is offline   Reply With Quote

Old   May 24, 2010, 21:35
Unhappy Burst Open of Valve
  #3
New Member
 
jitukrjain
Join Date: Mar 2009
Posts: 6
Rep Power: 8
jitukr is on a distinguished road
Two pipes are joined with a metal foil between them acting as a diaphragm. In first pipe piston moves and compresses gasses ahead of it. Compressed gasses bursts diaphragm and enters second pipe. I need to simulate this and find flow pattern, pressure temp, velocity, choking etc of gasses thus flowing through mouth in second pipe. Flow may reach sonic velocity and shocks may also be produced. I am not able find solution to rupture of diaphragm and simulate in CFX-Ansys as transient problem. My PhD thesis is stuck.
jitukr is offline   Reply With Quote

Old   May 24, 2010, 21:40
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,929
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Isn't a good starting point simply modelling the impulsive start (ie starting from rest) of the shock tube? That is, it has an initial condition and you suddenly impose a high pressure at one end (ie rupture) and this causes a high speed flow? When you have got this working well and you know how to do it properly then consider the secondary effects caused by the actual rupture process (if that is important at all).

Start simple and build the physics in one step at a time. Forget about the rupture for the moment.
ghorrocks is offline   Reply With Quote

Old   May 25, 2010, 21:50
Default
  #5
New Member
 
jitukrjain
Join Date: Mar 2009
Posts: 6
Rep Power: 8
jitukr is on a distinguished road
Bursting of diaphragm is important as it is deciding factor for flow in second tube. I think that it can be solved through (first) If diaphragm is modeled as assembly of 12 circular sector and sector are fixed at periphery but meet at center. Each sector is bound at edges with each other. Each sector bends under pressure and against binding force at edges. I think Binding of components is allowed in Ansys 12 only. I am able to model Ansys-Cfx transient simulation in Ansys 11(Without bursting of diaphragm) but not very sure as how to proceed in Ansys 12.(second) I think Ansys Autodyn 12 or LS DYna allows rupture or bursting; so coupled with CFX it can be solved; but I don;t know how to work upon Autodydn or LS dyna. Are there any tutorial available for transient analysis in Ansys-CFX 12 and some tutorial on Autodyn or LSDyna in Ansys WB 12
jitukr is offline   Reply With Quote

Old   May 25, 2010, 22:39
Default
  #6
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,929
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
OK - so I take it you can model this type of high Ma flow without the bursting? You had not mentioned that before. Obviously you have to be able to model this before you can add the more complex bursting issue.

Due to the large deformations in the bursting process you will need to have remeshing in there to stop inverting elements. Talk to CFX support about some demo examples of how to do this.

I have no information about Autodyn of LSDyna - wrong forum.
ghorrocks is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
wmake compiling new solver mksca OpenFOAM Programming & Development 13 August 18, 2014 22:26
openfoam 1.6 on debian etch romant OpenFOAM Installation 9 May 6, 2010 02:26
Problem installing on Ubuntu 9.10 -> 'Cannot open : No such file or directory' mfiandor OpenFOAM Installation 2 January 25, 2010 10:50
DxFoam reader update hjasak OpenFOAM Post-Processing 69 April 24, 2008 01:24
OpenFOAM with IBM AIX matthias OpenFOAM Installation 20 March 25, 2008 03:36


All times are GMT -4. The time now is 21:24.