Numerical study of turbulence anisotropy effect on particle deposition rate using DNS data

Numerical study of transportation of nano and micro particles in a fully developed turbulent channel flow have been studied. A hybrid method is applied to study this work. The continuous phase is solved in the Eulerian frame. Finite volume method is used to solve steady state conservation of mass and momentum equations. Anisotropy DNS data for turbulent intensities are used in the analysis. The dispersed phase is solved in the Lagrangian frame of reference. It is assumed that particles have no feedback effect on the carrier gas and particle-particle interactions are neglected (one way coupling). The Lagrangian particle tracking model has been used to include particle inertia, crossing-trajectory and continuity effects. The computational predictions of particle deposition velocity are compared with the available experimental data. It is found that consideration of turbulence anisotropy is critical for proper simulation of nano and micro particle depositions in the turbulent flows. Isotropy assumption leads to over prediction of nano and micro scale particle deposition rates. Except for the region very close to the wall, results show that turbulence is the dominating dispersing mechanism. Key-Words: DNS, turbulence, anisotropy, Lagrangian, multiphase flow, particle