Averaged Sauter Mean Particle Diameter

sjtusyc · September 7, 2012, 08:37

I wanna to get the " Averaged Sauter Mean Particle Diamete " at a specific surface,say outlet.
I turn to the Function Calculator.
But what function should i select,as the Sauter Mean Particle Diameter is an averaged diameter.

I tried areaave, massflowave,minVal,maxVial functions, and i get different results.
*

areaAve_z(water.Averaged Sauter Mean Particle Diameter)@out (it has a direction?)
massFlowAve(water.Averaged Sauter Mean Particle Diameter)@out
massFlowAve(water.Averaged Sauter Mean Particle Diameter)@out

Anyone who has this kind of experience?

Thanks in advance.

sjtusyc · September 8, 2012, 08:54

I am waiting for your anyone to reply.Thanks

ghorrocks · September 9, 2012, 06:35

That's because areaAve, massflowAve, minVal, maxVal are all different. It have nothing to do with Sauter mean diameters. Look in the CEL reference guide to understand what these functions mean.

sjtusyc · September 10, 2012, 03:34

Thank you fore your reply.
I read the corresponding part in the help documentation and is clear about these functions,they just use different weighting factor.
But i was still confused that why there is always an 'averaged' before particle variable.
eg, Averaged Sauter Mean Particle Diameter, 'mean' already means averaged.

murx · September 10, 2012, 06:36

From the notation of "water.Averaged Sauter Mean Particle Diameter" it seems that it is an output variable of your solver. So it is stored for every control volume. I guess in this case, "mean" means averaged over the control volume (so over 1 cell).
EDIT: I just read the other thread you started. I figured you are trying to simulate a spray and the sauter diameter you are refering to is the diameter of the drops. It's probably a bad idee to try to calculate the sauter diameter of drops that have a specific shape/volume and are smaller than your control volume

So forget this part of my answer...

If you want to get the average sauter diameter of particles flowing through your outlet, massFlowAve() is probably the function you should use.

sjtusyc · September 10, 2012, 09:53

Thank you for your elaborate answer.I think you got some points.
There are two kinds of variables.One from Euler point of view,say,control volume
as your said ,nodal value.The other one is from Lagrange point of view,like the SMD i want to get.
It seem that CFD-post only in support of the variable in Euler point of way.

September 7, 2012, 08:37	Averaged Sauter Mean Particle Diameter	#1
sjtusyc Member leo Join Date: Jun 2012 Posts: 98 Rep Power: 13	I wanna to get the " Averaged Sauter Mean Particle Diamete " at a specific surface,say outlet. I turn to the Function Calculator. But what function should i select,as the Sauter Mean Particle Diameter is an averaged diameter. I tried areaave, massflowave,minVal,maxVial functions, and i get different results. * areaAve_z(water.Averaged Sauter Mean Particle Diameter)@out (it has a direction?) massFlowAve(water.Averaged Sauter Mean Particle Diameter)@out massFlowAve(water.Averaged Sauter Mean Particle Diameter)@out Anyone who has this kind of experience? Thanks in advance.

September 10, 2012, 06:36		#5
murx Member Max Join Date: May 2011 Location: old europe Posts: 88 Rep Power: 14	From the notation of "water.Averaged Sauter Mean Particle Diameter" it seems that it is an output variable of your solver. So it is stored for every control volume. I guess in this case, "mean" means averaged over the control volume (so over 1 cell). EDIT: I just read the other thread you started. I figured you are trying to simulate a spray and the sauter diameter you are refering to is the diameter of the drops. It's probably a bad idee to try to calculate the sauter diameter of drops that have a specific shape/volume and are smaller than your control volume So forget this part of my answer... If you want to get the average sauter diameter of particles flowing through your outlet, massFlowAve() is probably the function you should use. Last edited by murx; September 10, 2012 at 08:00.

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September 8, 2012, 08:54		#2
sjtusyc Member leo Join Date: Jun 2012 Posts: 98 Rep Power: 13	I am waiting for your anyone to reply.Thanks

September 9, 2012, 06:35		#3
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	That's because areaAve, massflowAve, minVal, maxVal are all different. It have nothing to do with Sauter mean diameters. Look in the CEL reference guide to understand what these functions mean.

September 10, 2012, 03:34		#4
sjtusyc Member leo Join Date: Jun 2012 Posts: 98 Rep Power: 13	Thank you fore your reply. I read the corresponding part in the help documentation and is clear about these functions,they just use different weighting factor. But i was still confused that why there is always an 'averaged' before particle variable. eg, Averaged Sauter Mean Particle Diameter, 'mean' already means averaged.

September 10, 2012, 09:53		#6
sjtusyc Member leo Join Date: Jun 2012 Posts: 98 Rep Power: 13	Thank you for your elaborate answer.I think you got some points. There are two kinds of variables.One from Euler point of view,say,control volume as your said ,nodal value.The other one is from Lagrange point of view,like the SMD i want to get. It seem that CFD-post only in support of the variable in Euler point of way.