# fuel injection

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

 February 5, 2009, 06:25 fuel injection #1 Johannes P. Guest   Posts: n/a Hey!! I wanna simulate an injection of fuel(Dodecane(L)) into a high pressure cell. I wanna have a look to the length of the injected fuel jet and to the diameter and velocity of the fuel droplets. It's an Lagrangian Multi-Phase spray injection with atomization.The Atomization model is the "Huh-Model", the "MPI-2" is the nozzle model. Heat, Mass and Momentum Transfer are Standard with 0 for mass coef. and 1 for the slip factor. there is one inlet and one pressure boundary created. I wanna simulate pressures between 1e+05 and 100e+05Pa. That I can see how the pressure influences the length of my jet and the velocity and diameter of my parcels So, the problem is that the length of the jet is still constant. Doesn't matter if the pressure in the cell is initialized to 1e+5Pa or to 500e+5Pa. So, what's wrong with my simulation? I'm running the code of version 3.26. Maybe you've an idea;-) Thanks a lot. Johannes P.S. I'm a student from Germany, so sorry for my bad english ;-)

 February 5, 2009, 07:42 Re: fuel injection #2 Kian Mehravaran Guest   Posts: n/a Hi Johannes, Are you using RANS or LES? Also, when you say length of your jet, do you mean the liquid jet, or the gas jet? Kian Mehravaran

 February 5, 2009, 08:08 Re: fuel injection #3 Johannes P. Guest   Posts: n/a HEY Kian, i mean the length of the liquid jet (the length of the fuel jet). What's RANS or LES? Thank you very much. Johannes

 February 5, 2009, 08:26 Re: fuel injection #4 Andrea Guest   Posts: n/a RANS = Reynolds Averaged Navier Stokes equations, LES = Large Eddy Simulation, they are two ways of modeling turbulence...two radically different approach. Try to look at the cfd wiki for more info For the injection problem, do you get the correct pressure (the pressure you want) in the injection chamber? Have you verified that? Regards

 February 5, 2009, 09:14 Re: fuel injection #5 Johannes P. Guest   Posts: n/a hey! ok, than i use RANS! I get definitely the right pressure in the chamber. try tp find sth. in the WIKI. thanks, Johannes

 February 5, 2009, 10:07 Re: fuel injection #6 Kian Mehravaran Guest   Posts: n/a Now the next question is how do you calculate the length of the liquid jet? By looking at the volume fraction? or do you look at the droplets directly? What is the temperature in the chamber? It could be that evaporation is very dominant in your case. Kian Mehravaran

 February 19, 2009, 09:45 Re: fuel injection #7 Daniel Guest   Posts: n/a Hello Johannes, Although I am not familiar with star, my first guess is that you are doing an incompressible simualtion. In that case, the results do not depend on the actual level of the pressure, but just on the pressure gradient. If so, both initializations should lead to the same results. regards

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Maria CD-adapco 1 August 25, 2007 09:02 Rams FLUENT 12 June 20, 2006 01:25 Derry CFX 1 January 30, 2006 22:38 mujahid FLUENT 1 February 19, 2004 07:36 Enrico CD-adapco 2 December 23, 1999 04:37

All times are GMT -4. The time now is 09:08.