Effects of Lewis number on conditional fluid velocity statistics in low Damköhler number turbulent premixed combustion: A direct numerical simulation analysis

摘要: The effects of global Lewis number Le on the statistics fluid velocity components conditional in unburned reactants and fully burned products context Reynolds Averaged Navier Stokes simulations have been analysed using a Direct Numerical Simulations (DNS) database statistically planar turbulent premixed flames with low Damkohler ranging from 0.34 to 1.2. extracted DNS data respect well-known Bray-Moss-Libby (BML) expressions which were derived based bi-modal probability density function reaction progress variable for high flames. It has shown that substantially affects mean fluctuation correlation products, effect being particularly pronounced Le. As far as are concerned, BML agree reasonably well reported present work. Based priori analysis previously data, empirically modified here order account effects, non-bimodal distribution variable. Moreover, it demonstrated first time surface averaged stresses can be modelled without invoking involving number, these quantities remain approximately equal their conditionally counterparts mixture.