An eddy interaction model for particle deposition

Abstract

Deposition of mono-disperse aerosols is studied numerically on a simplified human upper airway model (UAM). This paper presents new correction functions for eddy interaction model (EIM) in an attempt to improve the accuracy of predicting aerosol deposition in the UAM. Based on an Euler-Lagrange methodology, the fluid phase is solved using RANS (Reynolds Averaged Navier Stokes equation) and employing low-Reynolds SST k-ω turbulence model. The particle phase is solved using Lagrangian approach and employing an EIM model. Mono-disperse particle sizes of 3 and 6μm are considered for breathing rates of 30 and 60L/min. The proposed method of correction functions to EIM (“helicity EIM”) is compared to the classical EIM assuming isotropy (“isotropic EIM”) and to the EIM incorporating correction functions of Wang & James (1999) (“Wang and James EIM”). All three EIM methods are validated against experimental data of deposition efficiencies reported for a 90° bend pipe and for the UAM. In the latter case, total as well as compartmental deposition efficiencies are used for validation purposes. In both geometries, the present approach (“helicity EIM”) predicts the deposition efficiency better than the “isotropic EIM”. The results obtained with “helicity EIM” are of similar accuracy compared to those of “Wang and James EIM”. Considering that the “helicity EIM” does not require the estimation of y+ for each case, we suggest that this could be the preferred EIM correction method for simulation of respirable range aerosol particle deposition in the mouth-throat.