Particle-resolved numerical simulations of char particle combustion in isotropic turbulence

In the present study, two-dimensional particle -resolved numerical simulations of char particle combustion are performed. A series of cases are considered, with varying turbulence intensities and heterogeneous reaction rates. The impact of turbulence and Stefan flow on char particle combustion is examined. It is shown that the cases with higher turbulence intensity and heterogeneous reaction rate exhibit higher mean gas -phase temperatures and reaction rates. The range of the Stefan flow Reynolds number ( Re S ) increases as the value of heterogeneous reaction rate increases. Additionally, higher turbulence intensity is associated with an increased range of Re S . The drag force coefficient of burning particles is analyzed. The results show that turbulence induces fluctuations of drag force coefficient, and increasing the turbulent velocity broadens the drag force coefficient fluctuation amplitude. The particle drag force is increased with increasing heterogeneous reaction rate. The pressure and viscous components of the drag force are examined. It is revealed that the increase of heterogeneous reaction rate alters the pressure distribution on the particle surface, resulting in the increase of pressure drag force, while the viscous drag force remains almost unchanged.