Hi all,
I am doing CFDEM coupling for significantly small particle size (50micron) that is suggested to use cgs unit. Thank to CFDEM project team for making a case tutorial in terms of cgs unit, I have found and tested tutorials ErgunTestMPI-cgs. I also tried and compared the same cases with and without copying ControlDict file to .OpenFOAM directory. It is surprised to see that the results in both cases (with and without Unit conversion) are not different. Note that I did not change anything in the ErgunTestMPI-cgs tutorial except disabled ControlDict file.
Furthermore, I create the same case with ErgunTestMPI_cgs but change unit to SI (change U,p,nu,g....). I check carefully to ensure all fields matched properly between cgs and SI. However, the result in both cases are not completely the same. I think the dimensions of particles in tutorial case is not really small (0.011m) so the result calculated in both Unit systems should be exactly the same.
Does anyone has experience on this problem, please give me a hint? Do I need to do something else a part from copying ControlDict file?
I am looking forward to your sharing.
Thank very much,
Best regards,
Nathan,