Learning Forum

[Aravinth Ekamparam]

Is there any way to capture the exact particle diameter in dpm simulations other than particle mean diameter in fluent?

I am using Rosin Rammler distribution for my particle size distribution and injecting particle diameter 80 to 200 micron. After the simulation, I checked the particle mean diameter. It is showing some of the particles are around 30 micron. I am wondering how it calculates the particle diameter? Thanks in advance.

Aravinth

[Rob]

Please can you post a screen grab of the injection(s) panels? I want to see what's set. What other models are active?

[Aravinth Ekamparam]

Yeah sure. Below are the screenshots. I added particles from 80 to 170 microns using RR distribution. In the post-processing, there was no option for particle diameter. Only Particle mean diameter was available. But during the analysis, I could see the variation particle diameter with time.

here some of the particles did not reach the point selected. You can able to see it in 500 to 1000 micron particle.

The corresponding injection page is here. Rest all the settings are the same.

[Aravinth Ekamparam]

My particle diameter ranges from 500 to 1000 micron. But you can see the particles of diameter 350 to 400 microns (second last figure). Is there any reasons for this type of behavior? and how to get the actual diameter of particle at a point in a transient analysis. Thanks.

[Rob]

Are you judging diameter by the contour or DPM report? If it's the latter it shouldn't, for the former check the definition used in the solver. 

To get DPM data during the run use the DPM Reports and .out files.  I tend to prefer to set some number of injections each with a single diameter when trying to see what sizes go where. If the particles aren't coupled with the flow it's quick and very clear what's going on.