The investigation of the correlation between turbulent parameters and pressure variations during engine flame development [Motor alevġ gelġġġmġnde türbülans parametrelerġ ve basinç deǧġġġmlerġ arasindakġ ġlġġkġnġn ġncelenmesġ]

The objective of this study was to investigate the effects of turbulence in cylinder on flame and pressure development under various engine running conditions. in the study,mie scattered laser sheet methane-air flame images,captured from a single cylinder optically accessed spark ignition engine operated at 1500 rpm,were used. the time between frames was 0,1 milliseconds. contours of methane flames were subtracted from images using visualization techniques. a mathematical treatment of wrinkles of flame surface was predicted applying the spectral analysis method to the samples of flame contours. integral length scale,flame brush thickness and mean flame radius were measured from the spectral analysis of flame images. in addition,indicated mean effective pressure and mass fraction burned values were calculated from the pressure data measured simultaneously with flame images. turbulent parameters and pressure related parameters were than compared depending on crank angle for the engine running conditions of two different swirling flow conditions (0° and 40° swirl ports) and two different spark plug location (central and mid-radius ignition). findings showed that the swirl created in cylinder had an effect of increasing the turbulent intensity of fluids,thereby accelerating the combustion speed by means of increasing the turbulent flame brush thickness. results also showed that the eddy structures (by means of their intensity and scale) appeared in cylinder and their positions with respect to the spark plug were quite important in terms of combustion phases. a relationship was also found between pulses in pressure data and variations in turbulent parameters. ©2008 tibtd printed in turkey.