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Tip vortex cavitation (TVC) is an important cavitation phenomenon in marine propeller. The formation and evolution of tip vortex cavitation are hot topics consistently both in engineering application and mechanism research. In this paper some recent studies on tip vortex cavitation inception and the noise of tip vortex cavitation evolution are presented. The effects of both flow field and water qualities on tip vortex cavitation inception are considered by experiments and numerical simulations. The results show that besides the average minimum pressure in the vortex core the turbulence fluctuation and water qualities including air content and nuclei distribution have great influence on tip vortex cavitation inception. Based on the idea of first nucleus cavitating in tip vortex core new prediction formula for tip vortex cavitation inception is proposed. The synchronous technique of high speed video observation and noise measurement are adopted to study the development of tip vortex cavitation. S-type total noise characteristics are obtained when cavitation number from low to high. Vortex singing is found in the case where the tip vortex cavitation just before leaves the tip region. The excited mechanism of vortex singing is proposed by analyzing the wave propagation on the interface of vortex cavity. [ABSTRACT FROM AUTHOR]

The inception of tip vortex cavitation is very sensitive to water quality. In order to quantify the effect of water quality on the inception of tip vortex cavitation, we develop a motion model to describe the migration and growth of nuclei in water. An analytical solution of migration of nuclei in a vortex flow is obtained so that the capture times of various nuclei can be given out directly. A criterion is built to determine the critical nucleus in a certain nuclei spectra distribution. Tensile strength of the critical nucleus is used to quantify the effect of water quality and correct the tip vortex cavitation inception number. Finally this change of cavitation inception number is compared with experimental results to validate our model. [ABSTRACT FROM AUTHOR]

Kuiper and Jessup (1993) developed a design method for propellers in a wake based on the Eppler foil design method. The optimized section is transformed into the three-dimensional propeller flow using the approach of the effective blade sections. Effective blade sections are two-dimensional sections in two-dimensional flow which have the same chordwise loading distribution as the three-dimensional blade sections of a propeller. However, the design procedure is laborious in two aspects: finding an optimum blade section using the Eppler program requires much skill of the designer, and transforming the two-dimensional blade section into a propeller blade section in three-dimensional flow is complex. In this work, these two problems were coped with. A blade section design procedure was presented using an optimization technique and an alternative procedure for the effective blade section is developed using a lifting surface design method. To validate the method a benchmark model of a naval ship was used. This benchmark model was extended by new appendices and a reference propeller, and designed using conventional design methods. This reference propeller was optimized using the new design procedure and model tests were carried out. Special attention was given to the data of the model and the reference propeller, to make the configuration suitable for the Reynolds-Averaged Navier-Stokes (RANS) calculations. [ABSTRACT FROM AUTHOR]