Difference between particle and DPM variables

[aniruddhabose96]

Hi

In the attached picture, is phi inside the summation a particle variable or DPM variable? As far as i understood DPM variables are cell averaged values of particle (lagrangian) variables. Am I correct? This is not very clear in the user guide because there is some mixed terms there. 

[Rob]

What is it being reported on? If it's referring to a number of parcels in a cell it's likely a cell value as a particle value is held on the parcel track. 

[aniruddhabose96]

Yes the result is a cell value but the phi within summation is summed over number of parcels or particles and then the cell value is returned. Is this a correct interpretation?

[Rob]

Does it give you the value you want to post process? 

[aniruddhabose96]

 

If the quantity inside the summation is particle variable, then yes. Also I am assuming when you time avg the particle velocity then all the fluctuations becomes zero and we only get the mean vel of particles.

 

[Rob]

How are you averaging the particle velocity in the Lagrangian framework? 

[aniruddhabose96]

If you see the above definition, the summation runs from 1 to N parcels or particles. So that automatically averages the particle properties in the lagrangian framework and then wighed by the number of parcels and residence time to give a cell value. Is that correct?