Experimental study and numerical investigation of particle penetration and deposition in 90° bent ventilation ducts

Particle deposition in a ventilation duct is a severe problem as it can pose health hazards. This is more evident in 90° bent ventilation ducts. The exposure of particle deposition location in bend section is important and useful in understanding and dispelling particle contamination. This paper investigated particle penetration and deposition in 90° bent ventilation ducts numerically and validated using experimental and previous research data. In the numerical study, particle penetration and deposition in a 2D 90° bend turbulent flow were analyzed. The Renormalized Group (RNG) k- model and Lagrangian particle tracking model were utilized to characterize turbulent gas flow and particle behavior, respectively. Particle turbulent dispersion was introduced by adopting the eddy lifetime model with the near wall fluctuating velocity corrected to take turbulence anisotropy into account. In the experimental validation, particle pollution collected from an actual ventilation duct was observed. The particle penetration rates in a test duct at 6 different Stokes numbers were measured for validation. The numerical results were consistent with both the experimental study and the data obtained from previous research.