LDA Flow Rate Measurements Applied for Analysis of Transient Injection Characteristics

Abstract

In the present study an LDA-based technique was applied to analyze details of a transient pipe-flow induced upstream by a fuel ingector. Due to highly accurate measurements of the instantaneous time series of velocity, fuel flow rate and pressure gradient were achieved. The pipe flow has been driven under an injection pressure of 0.6MPa at high injection frequencies of 25 and 50 Hz. The influence of the outflow orifice diameter, varid in range from 100 to 500 μm, on the transient pipe flow dynamics has also been described. The results show that transient behavior of rapid oscillating pipe flow is remarkably and systematically dependent on injection frequency and duration as well as on the orifice diameter.