[LarLar]

Hello, everyone here

I'm doing a multiphase model with gas/water/particle, and set the water as Primary phase, air as Secondary phase, and the particle as discrete phase .

And here is my question:

1. the equation of DDPM is showing below :



and I'm not sure if the discrete phase interacts with the secondary phase or not? if it's not, why can we still set the drag coefficient between two fluids and particle phase? (shows below)




2. the equation of particle motion is showing below :



u is the fluid phase velocity, and as there's two fluid in my model, I wanna know what the "fluid" exactly is? the primary one /secondary one or the average between them?



Best Wishes