Further Studies of Cavitation and Atomization in Diesel Injection

The paper describes how laser light sheet illumination was used to study the onset and development of cavitation in a scaled up plain orifice nozzle. In addition, measurements were taken using laser Doppler velocimetry and the refractive index matching technique, and these establish the velocity profiles within the orifice under non-cavitating conditions.

The light sheet makes visible new detail in the cavitating flow field and additional stages in the cavitation process are identified. The mechanism which causes hydraulic flip is demonstrated and confirms the authors' hypothesis from previous studies.

An investigation into the form which the cavitation takes is included: flow conditions are demonstrated in which the cavitation produces an opaque mass of small bubbles, and alternative conditions in which large transparent vapour pockets are produced.

The increased visibility enabled by the technique provides new insight into the mechanism by which cavitation influences the atomization of the jet.