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The effect of freestream nuclei content on stable cavitation about a hydrofoil and subsequent microbubble production in the wake is investigated experimentally. Microbubble concentrations are measured upstream and downstream of the hydrofoil for four upstream nuclei concentrations and three cavitation numbers. For each case the number of activated nuclei on the hydrofoil and the transverse distribution of concentrations in the wake were measured. Upstream nuclei concentrations were measured with interferometric Mie imaging in the size range between 45-250 µm at concentrations up to 30 cm⁻³. Wake microbubble concentrations were measured using shadowgraphy in the size range 5-50 µm at concentrations up to 600 cm⁻³. Wake concentration were found to increase for small changes in low upstream nuclei concentrations but to then decrease for further increase in concentrations. Wake concentrations were found to generally increase with decrease in cavitation number for a particular upstream nuclei concentration. The increase in wake bubble concentrations with seeding increase, at the high cavitation number, is in the smaller bubble size range whereas the increase at the lower cavitation numbers occurs over a greater size range.

Item Type:	Refereed Conference Paper
Keywords:	nuclei, attached cavitation, microbubble wake
Research Division:	Engineering
Research Group:	Maritime engineering
Research Field:	Ship and platform structures (incl. maritime hydrodynamics)
Objective Division:	Defence
Objective Group:	Defence
Objective Field:	Maritime
UTAS Author:	Russell, PS (Mr Patrick Russell)
UTAS Author:	Venning, JA (Dr James Venning)
UTAS Author:	Brandner, PA (Professor Paul Brandner)
UTAS Author:	Pearce, BW (Dr Bryce Pearce)
UTAS Author:	Giosio, DR (Dr Dean Giosio)
ID Code:	136215
Year Published:	2019
Deposited By:	NC Maritime Engineering and Hydrodynamics
Deposited On:	2019-12-06
Last Modified:	2020-03-17
Downloads:	14 View Download Statistics