Learning Forum

[Fathina Izmi]

Hello,

 

I'm looking to simulate the distribution & dispersion of Particulate Matter (PM2.5, PM10) in a building from smoking cigarette activity. What are the analysis systems that need to be used? Is it Fluent or CFX? And what are the models that we need to simulate the particles? I'm seeing Species Transport & Discrete Phase as options in some similar research but can't figure out the difference or which is best for my case.

In term of the PM, what are the data that need to be inputted to represent the characteristics of PM pollutant?

 

I'm a newcomer to Ansys Fluent. I only had experience simulating airflow & temperature inside a building in a steady state using Fluid Flow (fluent) system with different building ventilation scenarios. Please help me with any basic or detailed information, Thank you ????.

 

[Rob]

Fluent and CFX are both general purpose CFD solvers so either are good. I'd favour Fluent as I've been using it a while, and it's more common in industry. 

Next are the models. For smoke (particles) do you need to model the particles or can you assume they're a species? What is the relaxation time of the particles? 

[Fathina Izmi]

I think it would be better if I can model the particles. Sorry, I still can't find the relaxation time of PM2.5. Do I need that information to simulate the particle? Data that I have about PM2.5 is the particle density (0,8 –2,5g/cm3) and the indoor deposition rate is 0.39 ± 0.16 h−1. 

Thank you for the reply anyway.

[Rob]

Relaxation time, it's how long it takes the particle to reach the flow speed. It's a parameter to work out if you need particles or if it's a species. 

If you want to model particles then you need to consider if you want DPM or Eulerian/Mixture based on volume fraction and how the different models behave.