Flame-sheet dynamics of bluff-body stabilized flames during longitudinal acoustic forcing

Large Eddy Simulation of the Sensitivity of Vortex Breakdown and Flame Stabilisation to Axial Forcing

“…These phenomena are generally referred to as "combustion dynamics", and constitute one of the most challenging areas in combustion research [3]. The flame response to axial oscillations has been deeply investigated by researchers in the recent years in both non-swirling [4,5] and, as the current study, swirling flames [6][7][8][9][10][11]. Because of the intrinsic unsteadiness of the phenomena, the dynamics of swirl-stabilised flames (i.e.…”

“…The bar in (1)(2)(3)(4)(5) denotes presently the LES-low pass spatial filter which removes the subgrid scale turbulence.…”

Coordinate Systems and Integration Limits for Global Flame Transfer Function Calculations

“…For example, past studies have defined the flame position with respect to the axial coordinate [13,14], transverse coordinate [2,3,8] or in a coordinate system normal to the time averaged flame position [7,9,15]. To illustrate, the resulting expression written in the axial coordinate system is: (2) Here, x A ≡ x A (x, z, t).…”

“…Shin et al [13] and Shanbhogue et al [14] used the axial coordinate system for their study, as the position of shallow angle flames remains a single valued function of the coordinate for much larger amplitudes in that coordinate system. We focus attention for the rest of this note on the linearized flame area dynamics.…”

“…These end corrections for the bulk forcing problem are given by: Substituting eqns. (14) and (15) respectively into eqns. (8) and (10) yields the area fluctuations with the fixed width boundary condition.…”