Learning Forum

[ashirkhani]

Would any one explain to me what is the actual difference between "High-res tracking" on and off in DPM?

 

Thanks,

Amin

[ashirkhani]

I got these 2 completely difference particle residence time by just turning on and off the "high-res tracking".

[Rob]

Hi-res tends to be more accurate. In this case it looks like the difference is that the particles contact the base of the vessel and are trapped. Up to that point I suspect the trajectories are very similar. 

[ashirkhani]

Thanks for your reply.

Yes, before entering the nozzles, particle trajectories are the same. My simulation is based on an experiment and I am trying to validate the collection efficiency at the bottom of the collector. In reality, all the particles pass the nozzles and are trapped uniformly at the bottom of the collector.  The flow is laminar and the flow velocity is 0.25 m/s and the particle diameter is 1 um (uniform distribution). I set the trap condition on all the walls except for the inlet and outlet.

When I turned the high-res off, particles go through the nozzles just fine but right before contacting the bottom of the collector (which I wish happens for around 90% of them), they deviate from the straight line. 

I hope you can help me to fix that, I couldn't find any explanation for this behavior.

 

 

Thanks,

Amin

[DrAmine]

High Resolution Tracking rely on barcentric interpolation, is more accurate and robust. Standard Tracking has been there for a while and is not the default anymore and it is getting legacy.

[Rob]

As for why the particles follow the flow: look at the relaxation time for 1micron particles. They follow the flow so rarely hit anything.