Numerically investigation of the effect of initial temperature on the ignition in a shear-less mixing layer

Ignition process in a shear-less mixing layer has been studied in this paper. The effect of initial temperature on the flame propagation phase of ignition process is the main goal. The investigation is done by large eddy simulation method coupled with thickened flame approach and DRM_19 chemical mechanism. Mean and RMS axial velocities from both coarse and fine grids and mean mixture fraction have been validated against experimental results. Most upstream and downstream positions of flame edge are in good agreement with experimental. By increasing the initial temperature from 323 K to 1000 K, the mean edge flame propagation velocity increase from 1 to 4.5 m/s. The same trend exists for flame kernel volume. Comparison between calculated edge flame propagation velocity and laminar flame speed and its root density correction show that corrected laminar flame propagation can better predicts the edge flame propagation velocity. Also, by increasing the initial temperature, bibrachial edge flame convert to a triple flame.