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

how to give pressure as an input in spray modeling

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 5, 2008, 14:56
Default how to give pressure as an input in spray modeling
  #1
satish
Guest
 
Posts: n/a
hi, enybody who is working on spray modeling pls help me.

in the spray modeling for injection definition how to give injection pressure as an input parameter if i know the hole diameter and input pressure instead of mass flow rate? how to find the cone angle for the different injection pressure?

thanks and regards, satish
  Reply With Quote

Old   March 7, 2008, 21:23
Default Re: how to give pressure as an input in spray mode
  #2
Andrea
Guest
 
Posts: n/a
Hi
to model an injectio you really need to know the mass flow rate. if you know the pressure difference across your injector you can calculate the injection velocity (teorically). Then if you refer to the density of the liquid at your injection temperature you can calculate your mass flow rate, if you suppose a discarghe coeff. and you know the injector diameter. Even if you could define only the pressure difference, you need to suppose a discarghe coeff...so the first way is not so different for this second one.
With my experiment I've seen that Star calculate the injection velocity with reference on mass flow rate and geometrical data only...the effective injection velocity is function of cavitation and of injector model (MPI-1, MPI-2, effective)...
  Reply With Quote

Old   March 7, 2008, 21:30
Default Re: how to give pressure as an input in spray mode
  #3
Andrea
Guest
 
Posts: n/a
Excuse me,
for the question about the spray angle: use the Huh's atomization model (you'll choose injection with atomizatio I suppose...). With that you don't need to specify any spray angle because it is determined internally by the model (refer to the metodology for details)
Regards
  Reply With Quote

Old   March 7, 2008, 21:33
Default Re: how to give pressure as an input in spray mode
  #4
Andrea
Guest
 
Posts: n/a
...third thing: you can define an injection with an injection velocity independent of the mass flow rate...I don't know it it is useful for you but if it is I can tell you how to setup that sim...
Bye!
  Reply With Quote

Reply

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
What type of pressure can give the pressure drop david FLUENT 1 February 17, 2014 12:51
how can i give input for radiation problems balaji FLUENT 2 April 2, 2008 15:45
spray modeling saurabh dikshit CFX 1 July 23, 2007 06:20
spray modeling in cfx 11.0 skarp CFX 2 June 27, 2007 00:51
How to give Input Velocity in a 3-D cuboidal pipe Gaurav Deshpande CFX 1 January 13, 2006 23:49


All times are GMT -4. The time now is 10:36.