Propeller Induced Flow: Experimental In vestigation by LDV Techniques

The research activity in applied hydrodynamics is today mainly dealing with two topics, both allowed by advances in computer and instrumentation technologies: the development of sophisticated numerical approaches, more and more able to describe complex models; the possibility of performing experimental tests: by non intrusive measuring devices, from which information on local quantities can be derived. The cooperation between numerical and experimental research can today allow both of them to obtain significantenhancements. A typical example of the mentioned subject is the cooperation between the Dipartimento di Ingegneria Navale e Tecnologie Marine, Genoa University, and the INSEAN, Italian Basin of Rome. The two institutions have developed a research program with the aim of obtaining a complete mapping of the significant physical parameters describing the propeller induced flow, to be used in validation procedures of the numerical codes developed by INSEAN. Tests were carried out in the cavitation tunnel of Genoa University; two conditions were selected, the first with an advance ratio near to the propeller design point (high J); the second one referred to an off design condition, with relatively low 1. In the paper the measuring and data processing techniques are described, some or the experimental results obtained are shown and analyzed.