An Investigation of the Ignition Process in a Lean-Burning Engine Using Conditionally Sampled Laser-Doppler Anemometry

An investigation of the relationship between fluctuations in the flow field in the region of the spark plug and the efficiency of subsequent combustion has been carried out in a lean-burning engine. The experiment involved the application of conditional sampling techniques to laser-Doppler anemometry measurements.

Strong correlations were measured between mean velocity in the vicinity of the spark plug immediately preceding ignition and the peak pressure achieved; however, a much weaker dependence on turbulence intensity variations was observed.