The
propagation of premix methane/air flames in long half-open ducts with
different inclination angles θ between the sidewall and the
horizon was numerically investigated using the laminar model. The
numerical result was compared with the experimental and theoretical
ones to validate the numerical model. The results show that the numerical
results are in good agreement with them. The investigation provides
the basic understanding of the effects on changing the shape of the
ducts to promote the premixed flame combustion. For methane/air, the
position where the flame front begins to concave is pushed back with
the increase in angle θ. The so-called “tulip”
flame even disappeared, if the angle θ is bigger than one certain
value. Moreover, the flame propagation speed and pressure are enhanced
as the angle θ increases. In addition, the numerical simulation
indicates that the burning gas creates an eddy near the tip of the
flame, altering the flow field and causing the tulip flame to appear.
However, with the angle θ increased, the flame propagation is
restrained by the change in sidewalls, resulting in the different
flow patterns to suppress the formation of tulip flames and promote
flame combustion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.