A study of the evolution of nanoparticle dynamics in a homogeneous isotropic turbulence flow via a DNS-TEMOM method

In this article, a coupling of the direct numerical simulation (DNS) and the population balance modeling (PBM) is implemented to study the effect of turbulence on nanoparticle dynamics in homogenous isotropic turbulence (HIT). The DNS is implemented based on a pseudo-spectral method and the PBM is implemented using the Taylor-series expansion method of moments. The result verifies that coagulation due to turbulent shear force has a bigger impact on the evolution of number concentration, polydispersity, and average diameter of nanoparticles than Brownian coagulation in the HIT. The Reynolds number plays an important role in determining the number concentration, polydispersity, and average diameter of nanoparticles, and these quantities change more rapidly with an increase of Reynolds number. It is also found that the initial geometric standard deviation slows down the evolution of particle dynamics, but almost has no influence on the polydispersity of nanoparticles.