The optical characterisation of diesel flows and sprays

The paper will discuss three topics involving different aspects of diesel flows. The first topic will cover measurements of diesel cavitation flow obtained inside optically accessible real size diesel injector nozzles. The cavitation flow obtained inside the injector is observed to vary with fuel properties. The second topic will cover the combined impact of temperature and cavitation flow on diesel fuel. Cavitation is shown to induce a change in composition in diesel fuel, which is measured through a time-dependent variation in spectral absorptivity. The third topic will cover the application of laser sheet dropsizing to a diesel spray in a running diesel engine. The paper will review laser sheet dropsizing, and present the experimental configuration employed in the diesel experiment. The experimental data suggests a correlation between small droplets in the spray and lower soot volume fraction formed during combustion.