Swirl-stabilized auto-igniting spray flames are essential for designing
efficient and clean combustion systems. The present study performs large eddy
simulations (LES) of the dilute auto-igniting methanol flame in a vitiated, hot
coflow of varying swirl intensities. The six-dimensional Flamelet Generated
Manifold (FGM) technique is used to solve the reactive flow accurately and
economically. The swirl numbers (SN), i.e. 0.2, 0.6, 1.0, Und 1.4, are used to
assess their effect on auto-ignition and flame stability. At lower to moderate
swirl numbers (SN =0.2, 0.6), the increase in swirl is found to increase the
lift-off height. Beyond the critical swirl number (SN=0.6), the lift-off height
drops. Also, the time-averaged flame structure transitions from a tubular-like
flame into a uniformly distributed combustion region at these high swirl
numbers. It also results in a more compact flame for the higher swirl numbers.
These effects on flame dynamics are analyzed in detail using the mean gas-phase
flow field distribution, particle statistics, and proper orthogonal
decomposition (POD).

Dieser Artikel untersucht Zeitreisen und deren Auswirkungen.

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