Monitoring particle positions in steady state

Gert-Jan · November 27, 2018, 08:34

I have a steady state calculation with particles, fully coupled. Due to turbulent fluctuations, these particles are lifted to a certain height from a floor with obstacles. Now, I would like to know what the maximum height is these particles reach during my steady state calculation.

I tried the expert parameter 'monitor ranges=t', but the particle positions are not reported in this intermediate report.
Alternatively, a histogram with variables can be written to file after every particle track. Unfortunately, the particle positions are not available here as well.

Did I overlook something? Any idea?

ghorrocks · November 27, 2018, 18:28

Isn't this straight forward in CFD-Post? Or do you want to do it in the solver?

Gert-Jan · November 28, 2018, 04:08

Yes, I want to do it in the solver.

ghorrocks · November 28, 2018, 18:03

I am not very familiar with this so cannot help much.

But here's an idea which might (or might not) work: Assuming the height is in the y direction, define a variable step(particle.volume fraction-0.1)*y, and then the maximum height is the max() of this function. I have used a threshold of 0.1 volume fraction, other values might be more appropriate.

November 27, 2018, 08:34	Monitoring particle positions in steady state	#1
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,928 Rep Power: 28	I have a steady state calculation with particles, fully coupled. Due to turbulent fluctuations, these particles are lifted to a certain height from a floor with obstacles. Now, I would like to know what the maximum height is these particles reach during my steady state calculation. I tried the expert parameter 'monitor ranges=t', but the particle positions are not reported in this intermediate report. Alternatively, a histogram with variables can be written to file after every particle track. Unfortunately, the particle positions are not available here as well. Did I overlook something? Any idea?

November 27, 2018, 18:28		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	Isn't this straight forward in CFD-Post? Or do you want to do it in the solver? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

November 28, 2018, 18:03		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	I am not very familiar with this so cannot help much. But here's an idea which might (or might not) work: Assuming the height is in the y direction, define a variable step(particle.volume fraction-0.1)*y, and then the maximum height is the max() of this function. I have used a threshold of 0.1 volume fraction, other values might be more appropriate. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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November 28, 2018, 04:08		#3
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,928 Rep Power: 28	Yes, I want to do it in the solver.