Droplet Injection

varunrajendra · August 16, 2009, 07:48

I have been trying to simulate spray using single orifice atomizer (and pressure swirl atomizer) injector models. Liquid Diesel droplets into ambient air.

I have a doubt regarding use of Species Transport.

When I select a mixture in the species transport does it define the fluid domain as the mixture....??

The Particle Type = Droplet is disabled in the injector definition window. I am using k-epsilon turbulance model and also DPM...

I noticed that Droplet option gets enabled when i enable Species Transport. But i'm unable to understand how to get sort out the issue.

I would appreciate it if any one could tell me how to overcome this, or to use droplet model is it compulsary to use Species Transport?? and if yes how do i retain the domain to be ambient air??

Allan Walsh · August 18, 2009, 14:41

What are you trying to do? If you want to see how the vaporized diesel is dispersed, then you need to have an air-diesel mixture. If you only care about the condensed phase (i.e. liquid diesel drops), then the gas could be something else.
Probably, you want to choose air-diesel vapor from the Fluent data base for the fluid (i.e. gas) mixture. Then, chose diesel as the material for the particles from the material set up panel. Good Luck.

varunrajendra · August 18, 2009, 14:47

Yes I'm looking to injected liquid droplets and have set up the injector to do so....

Nope i'm not looking for vapourization... i'm trying to study droplet distribution...

Allan Walsh · August 19, 2009, 13:24

Sorry, I can't follow what you are trying to do or what your actual problem is.

varunrajendra · August 19, 2009, 13:46

I've managed to sort that particular problem out.... Thank you...

But i've got a couple more doubts.....

1. Pressure Swirl Atomizer in FLUENT does not seem to have an option to specify swirl component. I dont see any swirl in the spray produced by it. Is there any way that the swirl velocity component can be input....?
In simple words - How do i get swirl...???

2. Under advanced DPM Injections where the number of tracked particles, escaped....etc are listed out what does particles shed & incomplete mean...??

Please help....

Regards
Varun

August 16, 2009, 07:48	Droplet Injection	#1
varunrajendra New Member Varun Join Date: Aug 2009 Posts: 12 Rep Power: 17	I have been trying to simulate spray using single orifice atomizer (and pressure swirl atomizer) injector models. Liquid Diesel droplets into ambient air. I have a doubt regarding use of Species Transport. When I select a mixture in the species transport does it define the fluid domain as the mixture....?? The Particle Type = Droplet is disabled in the injector definition window. I am using k-epsilon turbulance model and also DPM... I noticed that Droplet option gets enabled when i enable Species Transport. But i'm unable to understand how to get sort out the issue. I would appreciate it if any one could tell me how to overcome this, or to use droplet model is it compulsary to use Species Transport?? and if yes how do i retain the domain to be ambient air??

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August 18, 2009, 14:41		#2
Allan Walsh Member Allan Walsh Join Date: Mar 2009 Posts: 56 Rep Power: 17	What are you trying to do? If you want to see how the vaporized diesel is dispersed, then you need to have an air-diesel mixture. If you only care about the condensed phase (i.e. liquid diesel drops), then the gas could be something else. Probably, you want to choose air-diesel vapor from the Fluent data base for the fluid (i.e. gas) mixture. Then, chose diesel as the material for the particles from the material set up panel. Good Luck.

August 18, 2009, 14:47		#3
varunrajendra New Member Varun Join Date: Aug 2009 Posts: 12 Rep Power: 17	Yes I'm looking to injected liquid droplets and have set up the injector to do so.... Nope i'm not looking for vapourization... i'm trying to study droplet distribution...

August 19, 2009, 13:24		#4
Allan Walsh Member Allan Walsh Join Date: Mar 2009 Posts: 56 Rep Power: 17	Sorry, I can't follow what you are trying to do or what your actual problem is.

August 19, 2009, 13:46		#5
varunrajendra New Member Varun Join Date: Aug 2009 Posts: 12 Rep Power: 17	I've managed to sort that particular problem out.... Thank you... But i've got a couple more doubts..... 1. Pressure Swirl Atomizer in FLUENT does not seem to have an option to specify swirl component. I dont see any swirl in the spray produced by it. Is there any way that the swirl velocity component can be input....? In simple words - How do i get swirl...??? 2. Under advanced DPM Injections where the number of tracked particles, escaped....etc are listed out what does particles shed & incomplete mean...?? Please help.... Regards Varun