Technical Paper
Investigation on Measurement of Diesel Spray Breakup Length by Using Doppler Signals
2001-03-05
2001-01-0533
New measuring methods of diesel spray characteristics were investigated by using laser Doppler signals, when diesel spray was injected into a high pressure vessel at room temperature(Injection under the high pressure means the simulation of injection atmosphere of diesel engine). We describe two methods of breakup length measurement, and these have great advantage compared with the conventional method using spray photographs. First, spray tip penetration was measured by the delay time of Doppler signals from injection start to spray tip arrival at each measuring point (measuring volume of Laser Doppler Velocimeter (LDV)), traversing the measuring point along the spray axis center line or offset line of the center line from nozzle hole towards downstream. Spray breakup length was measured as the inflection point of the curve drawing the delay time of Doppler signals versus the measuring points.