Abstract
The effects of the initial preheating perturbation on the dynamical behaviors of FGC wave propagation instability for low-velocity FGC in packed bed are studied numerically. The behaviors of the flame front inclination, break, and shrinking instabilities are always observed in experiments. Based on the experimental phenomena, an initial thermal perturbation model is numerically proposed as to predict the deformation behaviors of the flame front instabilities. The typical flame shapes are obtained depending on filtration velocity, equivalence ratio, and initial preheating temperature difference. It is demonstrated that the development of flame front inclination instability is proportional to the magnitude of initial preheating perturbation. At a lower equivalence ratio, the initial thermal perturbation of 300 K leads to the evolution of flame front break. Increasing filtration velocity leads to the appearance of flame front break, due to the intensification of the hydrodynamic instability. In addition, a perculiar instability of flame front shifting is also confirmed with the initial thermal perturbation of 400 K, which results in a fuel leakage of incomplete combustion.
Highlights
The inclinational instability of filtration gas combustion (FGC) wave propagation frequently occurs in inert porous media
The typical flame shapes are obtained depending on filtration velocity, equivalence ratio, and initial preheating temperature difference
It is demonstrated that the development of flame front inclination instability is proportional to the magnitude of initial preheating perturbation
Summary
The inclinational instability of filtration gas combustion (FGC) wave propagation frequently occurs in inert porous media. It was shown that the filtration wave propagation is hydrodynamically unstable if the reactor diameter of burner exceeds a critical value They analyzed the dependence of the FGC wave inclinational angle on both the gas-filtration rate and mixture compositions. It was found that the inclination amplitude growth velocity on the initial linear stage is proportional to the filtration combustion wave velocity, the reactor system diameter, and the inversed diameter of porous media particles.In addition, Zheng et al, Shi et al [4, 5] studied experimentally, numerically the effects of variation of different parameters on the inclinational angle growth of FGC flame front distortion. The main objectives are to manifest the characteristics of several wave propagating instabilities for low-velocity FGC, which are induced by initial temperature non-uniformity at the preheating section of burner. For various inlet filtration velocities and equivalence ratios, several combustion wave instability regimes are divided into several regions of existence in plot for the initial setting preheating temperature difference of 300 K
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
