Fully resolved simulations of single char particle combustion using a ghost‐cell immersed boundary method

Abstract

A novel ghost‐cell immersed boundary method for fully resolved simulation of char particle combustion has been developed. The boundary conditions at the solid particle surface, such as velocity, temperature, density, and chemical species concentration, are well enforced through the present method. Two semiglobal heterogeneous reactions and one homogeneous reaction are used to describe the chemical reactions in the domain, and the Stefan flow caused by the heterogeneous reactions is considered. A satisfactory agreement can be found between the present simulation results and experimental data in the literature. The method is then used to investigate the combustion property of a char particle and the interaction between CO2 gasification and O2 oxidation. Furthermore, combustion effect on the exchange of mass, momentum and energy between gas‐ and solid‐ phase is explored. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2851–2863, 2018

Immersed boundary method for multiphase transport phenomena

“…The Stefan flow velocity, temperature, and species distribution showed good agreements with analytical solutions and experimental data for both laminar and turbulent flows. Luo et al (2016b) improved a ghost-cell IB method so that it could handle all the Dirichlet, Neumann, and Robin types of boundary conditions and further extended it to perform a fully resolved simulation of char particle combustion (Luo et al 2018). In this study, the surface species transfer was a balance of diffusion, Stefan flow, and the heterogeneous reaction.…”

“…CO flame (shown as the contour of CO consumption rate) around the burning char particle (green cylinder in the figure) at different particle temperatures. Reprinted fromLuo et al (2018) with permission of John Wiley and Sons.…”

Direct Numerical Simulation of Reactive Fluid–Particle Systems Using an Immersed Boundary Method

“…The Boudouard reaction takes place at the outer surface as well as the inside of the porous particle, and the whole setup is two-dimensional and axi-symmetric. Luo et al 37 developed a DFM-based IBM to study the combustion process of a single char particle. Different reconstruction schemes are applied to enforce the boundary conditions of different variables, and the effect of surface reactions on the boundary conditions is accounted for by balancing the mass and energy at the gas–solid interface.…”