In-Cylinder LDA Measurements Using a Correlator

An LDA system using photon correlation technique and capable of handling non photon resolved signals is reported. Comparisons with the power spectrum of actual detector signals show that the correlation technique is very efficient. Turbulence production by means of swirl has been tested by making cycle resolved LDA measurements in a motored petrol engine for three different swirl levels. Firing tests of the engine show that the ignition delay (0 - 1% burned) correlates well with the high frequency components (> 1 kHz) of the turbulence at the spark plug location.