The effects of airflow velocities, particle sizes, and dust concentrations on the flame propagation characteristics and explosion behaviors of aluminum dust explosions in a horizontal pipeline were experimentally investigated. The results showed that the distributions of the airflow velocity and turbulence integral length both exhibited convex parabolic distributions. After ignition, the flame propagation velocities of 5 gm and 30 pm aluminum dust explosions both experienced acceleration processes. The positive feedback coupling among the combustion, expansion, and turbulence governed the acceleration mechanism. The flame propagation characteristics and explosion behaviors were significantly affected by the airflow velocity. As the airflow velocity increased from 6.4 m/s to 13.3 m/s, the maximum average flame propagation velocity increased from 60 m/s to 140 m/s. Moreover, the maximum explosion pressure increased from 36 kPa to 83 kPa, and the maximum explosion impulse increased from 78 Pa.s to 576 Pa.s. (C) 2019 Elsevier B.V. All rights reserved.