Learning Forum

[Shiyao]

Hi, 

I am using the Discrete Phase Model to simulate droplet groups. An injection of droplets is set in a surface inlet. The built-in Rosin-Rammler distribution is chosen as the diameter distribution in the injection. The setting is shown below. 

The droplet diameter distributions should be parabolic-like according to the setting. But it is uniform in the exported Particle History Data after running the simulation. The number of droplets in any initial size is constant in the data file. The skip is 0 and the coarsen is 1000 by default when exporting the particle data. 

I am wondering if there is something wrong with the setting of injection or exporting data. 

Best regards, 

Shiyao 

[Rob]

How many parcels are you tracking (read the TUI reports)? With 300 diameters do you have enough parcels to actually give a curve? Depending on what you're doing it's often better to set 3-5 injections each with a single diameter as you can easily visualise where each size is going. RR has it's uses, but it's not an option we use frequently. 

[Shiyao]

The report says 42000 parcels are tracked. Also, I was taking 50 diameters before, which shows the same profile. 

I understand that single diameter injections should be more stable. But I might have to add too many injections if I want to simulate an actual distribution in an experiment. What will you recommend in this case? 

[Rob]

How many columns do you plot when reporting the experimental data?  When setting injections the copy function can be very useful.... 

[Shiyao]

There are 21 columns.

I see your point in copying injection settings. Will it slow the simulation much if I have so many injections (or at least 11 injections as a half)?