Learning Forum

[Sardar]

Hi

I am doing DDPM in fluent. My flow simulation is steady and I want to find out the final distribution of particles across the stirred tank.

What I am looking for is to add [x] tons of a type of particle and see how it circulates in the domain of the tank. I am choosing group/surface, but there is no way I can introduce to the model the final total mass of powder.

In the window of the injection I have already defined, there is a "Total Flow Rate" of injection [Kg/s] that requires a user input. This just does not make sense as both my simulation and the particle tracking method are steady and unticked for "unsteady particle tracking" respectively.

How can I inject that amount of powder without having to deal with time?

[Rob]

I'd be looking at the Eulerian model for this - with DDPM you're solving an Euler granular phase and it'll almost certainly be transient.
In answer to the question you can use a volume injection but will need transient particles. Set the start time at zero and the stop time such that only 1 lot of particles are injected, ie stop time is a bit bigger than one particle time step but lower than two.

[Sardar]

This means injection span should outlive one particle timestep. Knowing exactly why is kinda beyond me, but that is for sure some invaluable information. Thank you so much, Rob.

[DrAmine]

You can use Volume Injection and inject certain mass of particles into the domain. Please use for that release 22R1.