I am simulating spray atomizer. Cold Water is rotating through rotating chamber. It comes out as droplet from nozzle.Hot air is coming in contact with water droplet . which model should I use for flow initialization? Is it multi phase or species transport or DPM in fluent?
Hi Somanath,
For spray modelling DPM is recommended. It treats water droplets as discrete phase. DPM computes trajectories of discrete phase and mass/heat transfer exchange between them as well as between the continuous phase (air in your case) and droplets.
You have to select appropriate models to calculate hydrodynamic drag, droplet break up, evaporation, etc.
Regards,
It depends on what you want to predict.
Are you looking to predict droplet sizes, trajectories and lifetimes?
Concentration of water vapor in the hot gas stream?
In that case, DPM is best option to proceed. There are various injection models to start with.
You may want to consider breaking this up into two models. One for the prediction of the droplet sizes and speed using VOF, and one using DPM for the trajectories and lifetimes.
Roland is correct, there are two ways to do this kind of analysis.
1. You can predict the input for injection modules in DPM to find out the mass flow rate and initial droplet diameter at the outlet of the spray nozzle. And then use that in injection properties to predict lifetimes and trajectories.
2. You can use coupled injection models like, pressure-swirl atomizer, plain-orifice atomizer, etc. Here you don't need to run VOF.
To clarify, DPM is best when you already know the droplet distribution, and initial velocity vectors.
Vidit is correct (I was incorrect) in that VOF is not the best choice to predict droplet pattern.
@ Vidit Sharma kindely tell me which model is best for evaporation with DPM in spray modeling?
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