CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Two-phase critical flow and shock modelling of nozzle

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 4, 2014, 10:12
Default Two-phase critical flow and shock modelling of nozzle
  #1
New Member
 
Jógvan
Join Date: Feb 2014
Posts: 22
Rep Power: 8
Jeggi is on a distinguished road
Hi.

I am trying to use the experiments from an article in order to validate two-phase critical flow and shocks for water-air in STAR-CCM+. (Sadly, the article is behind a payment wall).

The geometry and boundary conditions can be seen in the image below:


The air inlet has a pressure of 6 bar and the outlet has pressure of 2.44 bar. The mass flow rate of water is fixed at 498 kg/h.

I am using the Eulerian multiphase segregated flow solver with both water and air set to be compressible. I have been able to obtain reasonable results for the critical mass flow rate, but it has not be the case for the pressure profile along the nozzle as STAR-CCM+ does seem to over-predict the shock.
As of now, I have been using the S-gamma model in order to describe the interaction length scale for the two-phases by the Sauter Mean Diameter as recommended in the user guide (for droplets/bobbles). My issue is though that I don’t know if this model is applicable for my case?

It is also possible to set the interaction length scale to a constant, but I am hoping to avoid this as it will make it troublesome to transfer the validation case to a real case. Or is there a way to calculate the interaction length scale base on physical properties ?


Any help would be greatly appreciated.

- Jeggi
Jeggi is offline   Reply With Quote

Reply

Tags
critical mass flow rate, s-gamma, shock, two-phase

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Different flow patterns in CFX and Fluent avi@lpsc FLUENT 4 April 8, 2012 07:12
Con-Div Nozzle Shock structure problem padmanathan FLUENT 2 November 16, 2010 04:37
Nozzle flow simulation in inviscid and viscous Cath FLUENT 0 January 28, 2007 03:16
Nozzle Flow with shock jim clancy FLUENT 1 December 18, 2001 05:19
Inviscid Drag at subsonic, subcritical Mach # Axel Rohde Main CFD Forum 1 November 19, 2001 13:19


All times are GMT -4. The time now is 04:30.