Abstract
Keywords: Cavitation, Nozzle, PIV, Spray, Break-up
Cavitation through the nozzle of a diesel fuel injector is known to have a dramatic influence on the liquid jet atomisation. In order to investigate the relationship between cavitation cavity length and turbulence, high speed visualisation and particle image velocimetry (PIV) measurements have been conducted. Compressed air was used to drive filtered tap water through a large-scale, sharp-edged, acrylic nozzle with an L/d ratio of 5. Cavitation regimes ranging from incipient cavitation to supercavitation were explored and as a result the following conclusions were obtained: (1) Shed cavitation bubbles convected through the nozzle exit plane for the supercavitation regime have a dramatic influence on the liquid jet structure and aid the aerodynamic shear break-up of the jet. (2) Turbulent Kinetic Energy (TKE) was shown to be strongly linked to the cavitation cavity length and less dependent on Reynolds number.