A versatile numerical tool based on the open-source framework Open FOAM has been developed in this paper for modeling time-accurate,low-Mach number reacting flows,with a particular interest in small-scale flames.This ...A versatile numerical tool based on the open-source framework Open FOAM has been developed in this paper for modeling time-accurate,low-Mach number reacting flows,with a particular interest in small-scale flames.This tool consists of a gas-phase Navier-Stokes solver and a solid-wall heat conduction solver which can be implemented alone,or used together in a coupled means to reveal the small-scale combustion’s characteristics of significantly enhanced flame-wall thermal coupling.Validation works has proved that the tool is capable of reproducing experimental flames at various scales(from conventional to small scales),including well-recognized micro-flame features in literature such as three modes of premixed flame dynamics(weak flames,flames with repetitive extinction and ignition,and stable flames).Then,an experimentally-already-found but rarely-simulated unique phenomenon of diffusion flame street is successfully reproduced with well-captured flame structures.Moreover,the conjugate heat transfer model with the specific formulation of solid-wall heat conduction enables an attempt to simulate a novel,thermally-orthotropic combustor with its axial thermal conductivities superior to the transverse ones.Finally,computational performance of the developed Open FOAM solver is compared to that of the previously-used compressible flow solver Eilmer.The Open FOAM solver is found to show better wave-damping abilities for overcoming acoustic wave effects at the initial stage of simulations,and is much more efficient in terms of the computational cost.展开更多
基金funded by the National Natural Science Foundation of China(Grant Number 51806158)the Fundamental Research Funds for the Central Universities(WUT:2018IVA055,WUT:2019IVB029)。
文摘A versatile numerical tool based on the open-source framework Open FOAM has been developed in this paper for modeling time-accurate,low-Mach number reacting flows,with a particular interest in small-scale flames.This tool consists of a gas-phase Navier-Stokes solver and a solid-wall heat conduction solver which can be implemented alone,or used together in a coupled means to reveal the small-scale combustion’s characteristics of significantly enhanced flame-wall thermal coupling.Validation works has proved that the tool is capable of reproducing experimental flames at various scales(from conventional to small scales),including well-recognized micro-flame features in literature such as three modes of premixed flame dynamics(weak flames,flames with repetitive extinction and ignition,and stable flames).Then,an experimentally-already-found but rarely-simulated unique phenomenon of diffusion flame street is successfully reproduced with well-captured flame structures.Moreover,the conjugate heat transfer model with the specific formulation of solid-wall heat conduction enables an attempt to simulate a novel,thermally-orthotropic combustor with its axial thermal conductivities superior to the transverse ones.Finally,computational performance of the developed Open FOAM solver is compared to that of the previously-used compressible flow solver Eilmer.The Open FOAM solver is found to show better wave-damping abilities for overcoming acoustic wave effects at the initial stage of simulations,and is much more efficient in terms of the computational cost.
