Optical Measurement of Tip Penetration of a Diesel Fuel Spray : Development of Measuring Instrument

Abstract

A new optical measurement technique of tip penetration of a diesel fuel spray was developed. In this technique, arrival time of the spray tip at various locations distant from a nozzle was measured by detecting the interception of light sheets by a spray (the light sheet interception method). Then, the relation between the spray tip penetration and the time from the start of injection was obtained. The measurement accuracy was verified by photographing the spray intercepting the light sheet. The photograph shows that this new measurement technique is capable of measuring the spray tip penetration much more easily than the conventional photographic technique, and has sufficient accuracy. The effects of the operating conditions on spray tip penetration were also investigated by this technique. The measurement results of spray tip penetration varied with each continuous injection cycle, and the scattering increased with increasing distance from the nozzle or increasing ambient pressure.