Numerical study on the influence of fine particle deposition characteristics on wall roughness
This paper presents a study of the characteristics of a 1–50 μm particle deposition in a rib-roughened channel using a combined computational fluid dynamics-discrete element method (CFD-DEM). The effects of particle size, roughness element shape and surface energy on the deposition ratio are defined. Notably, The deposition rate of small particles (0.1<τp＋<1) is greatly improved, the particle size of medium particle size (1<τp＋<10) is small, However, the large particles (τp＋>10) have a lower deposition rate due to larger mass and inertia; Due to the different angles between the windward and leeward surfaces of rough elements with different shapes and the direction of airflow, the velocity fluctuation of the flow field in the duct and the eddies near the rough elements can make obvious changes. The deposition rate of a sharp-angle rough structure was the highest, while that of a triangular rough structure was the lowest. And the increase of surface energy the particles deposition rate increase.
Keywords: Gas-solid two phase flow, CFD-DEM, Particle deposition, Rib-roughened surface,