Numerical Investigation of Laminar Premixed Conical Flame Response to Acoustic Excitation

Abstract

Dynamics of laminar premixed conical flame in acoustic-velocity field was studied via numerical simulation. Methane/air combustion was modeled using a single-step, irreversible reaction and diffusion phenomena with a simple but efficient method. First, the steady flame was obtained and its corresponding parameters were verified. Then this steady state solution was excited by modulation of the inlet velocity. After the initial transients, heat release rate of the flame kept fluctuating with the forced frequency. The response function for various modulation intensities and frequencies agrees satisfactorily with experiments. Also, like the experimental observations the flame wrinkles and the convex sections which convert to sharp edges travel from the base to the tip of the cone at the speed of the flow.

Keywords

• combustion instability-laminar flame
• acoustic oscillations-methane flame