Global linear stability analysis of a flame anchored to a cylinder

This study investigates the linear stability of a laminar premixed flame, anchored on square cylinder and confined inside channel. Many modern analysis concepts have been developed validated around non-reacting bluff-body wake flows, objective this paper is to explore whether those tools can be applied with same success reacting flows in similar configurations. It found that instability steady flow states accurately predicts critical parameters for onset limit-cycle oscillations, when compared direct numerical simulation performed simple one-step reaction scheme low Mach number limit. Furthermore, strong stabilising effect flame ignition, consistent documented experiments simulations. Instability ignited is, however, set at sufficiently high Reynolds number, wavemaker characterises as being driven by hydrodynamic mechanisms nature flows. The frequency nonlinear oscillations unstable regime retrieved eigenmode time-averaged mean flow, under condition full equations linearised. If, contrary, unsteadiness density rate are excluded from model, then congruence between dynamics lost.