Effects of parcel modeling on particle dispersion and interphase transfers in a turbulent mixing layer

A three-dimensional particle-laden two-phase direct numerical simulation by employing the Eulerian-Lagrangian method is performed to investigate effects of parcel modeling on characteristics of particles' spatial dispersion, interphase mass and momentum transfers in a turbulent mixing layer. As the parcel models, two typical models such as the volume fixed model, VFM, in which each parcel has the same volume and the number fixed model, NFM, in which each parcel represents the same number of particles are examined. The case without the parcel model is also performed to compare with the models as a reference, RC. Results show that the parcel models significantly affect the particle dispersion, interphase mass and momentum transfers. It is found that NFM can qualitatively capture the trend of RC with small discrepancies, while VFM cannot reproduce it very much. The discrepancies become marked with increasing the number of particles represented by one parcel. The results suggest that the parcel models should be carefully treated with confirming the number of particles represented by one parcel in the entire range of particle size distribution.