[BuzzB]

Hi everyone,

I am currently trying to fully understand the sprayFoam solver, particularly the entries in sprayCloudProperties. ( I want to simulate a particle size distribution, together with the primary and secondary breakup options, but without combustion, chemical reaction or evaporization). There are some things which I didn't understand yet.

1. The flowRateProfile table under injection models. What does that exactly do? Giving a specific amount of mass (or parcels?) per time through the nozzle? How does that play together with parcelsPerSecond and the duration?

2. How does the atomizationModel and sizeDistribution work together? If I use LISA as the atomizationModel, doesn't that actually calculate the size distribution as a result? Why does OpenFoam need a sizeDistribution like RosinRammler than and how does it work together with LISA?

I really appreciate any help or further information you can provide me with.

Thank you!

[zarox]

Hi,

I am working on a similar topic and I have already puzzle out some little thing, as far as i have understand.
1. You give a parcel per second so using injected mass and and time duration the solver compute the mass to inject in the time step and divide this by the number of parcel.

2. The atomization model stand for primary breakup, it can start from a one size droplet (usually the size of the nozzle diameter) or it can start from a droplet size distribution. Also you can desactivate the atomization model and use only the breakup model (second atomization)

From my side, i am starting to wondering about the droplet size distribution implementation. Because the inject volume/mass necessary for time step is arbritrary split equally between the number of parcel for this injection time. The process is : you get with a random process droplet diameter from the distribution corresponding to the random volume fraction. But after the volume need for the injection time is split between parcel, and the number of particule is compute in order to match the volume need for this parcel. So, you have lot of droplet of small diameter. I am wondering if you get the original distribution from the diameter and number of droplet you have compute by this way. Perhaps, someone have well understand this and can explain. From commercial code documentation I know that the distribution must be volulitric to have a coorect process. But i don't get it.

Hope the first part can help. The second was more a thinging from my side...