[amoli123]

Hi Guys!

I am new to Fluent. I am trying to simulate liquid spray in a combustor. At present I am just trying to understand the effects of the fuel physical properties on the droplet size. I have attached the geometry sketch here.

There is NO combustion.

I want to study how the liquid spray develops from the injector.

I am planning to model 30 degree section of the combustor.

I would also like to couple the evaporation process of the droplets due to the air in the model.

1. I am wondering if I can couple evaporation/heat transfer of the fuel droplets formed from the injector due to the air flow field in VOF?

2. Which is the appropriate model I should use VOF or DPM? can the evaporation process of droplets be modeled only in DPM?

I guess problem with DPM is that they assume the initial droplet size?!

But I am trying to understand how the droplets develop from two different fuels. So I do not want to input the initial droplet size.

3. The liquid fuel is pressurized in the injector. If DPM is suitable to use, can I use plain-orifice atomizer?

4. Do I need to model air swirler? I guess, if the vane angle is known I can input the tangential and axial velocity directly.

Thanks!

[thermal energy]

you need to select DPM.

there are some tutorials of Fluent for DPM cases.

it will help you.

[openAC]

@amoli123

Were you able to find a solution to these questions? Could you please explain what you find?

Thanks.

[Jaydeep Kashikar]

I have a similar doubt. I want to study injection of water droplets within a volume which is ventilated and study the propagation of these droplets within the volume. Could i use VOF with DPM.

[user9]

You should go with dpm model. Moreover you can check the condition of dpm ( discrete phase volume should be less than 10%). Remember your mesh refinement should be such that the smallest volume element should be atleast 10 times greater than particle volume. If you are considering droplet evaporating you also need to activate species model.