Numerical study on flame propagation of nano- and micron-sized aluminum dust combustion in air.

A code was developed for numerical simulations of both nano- and micron-sized aluminum dust combustion in air. This code incorporates a combustion model that provides a comprehensive framework for modeling the burning of an aluminum particle under a transition regime, enabling accurate modeling of aluminum dust combustion across a wide range of particle sizes. The pseudo-transient approach was employed to solve the steady multiphase governing equations of aluminum dust combustion. The predicted variation trend of burning velocity with varying dust concentration exhibits good agreement with experimental measurements for both nano- and micron-sized aluminum dust combustion. Analyses exploring the effects of dust concentration, oxygen volume fraction and thermophoretic force on aluminum dust combustion were conducted. Simulation results indicate that introducing thermophoretic force in micron-sized aluminum dust combustion further enhances burning velocities and increases flame thicknesses compared to nano-sized aluminum dust combustion, primarily attributed to reduced gas entrainment of micron-sized aluminum particles. [Display omitted] • A code was developed for simulating nano- and micron-sized aluminum dust flames. • A model was proposed for aluminum particles burning under a transition regime. • The pseudo-transient approach was adopted to solve the steady-state flame. • The effects of thermophoretic force on aluminum dust combustion were revealed. [ABSTRACT FROM AUTHOR]