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Results of the experimental work aimed at characterising the hydrodynamic performance of a 7000 DWT chemical tanker are presented. This vessel is selected as representative of existing merchant ships equipped with conventional screw propellers. The present report is written in fulfilment of the STREAMLINE Project Deliverable D21.1 'Results of model tests on reference configurations.' The work documented herein is performed in the framework of Work Package 21 in which propulsion efficiency enhancements deriving from the application of advanced CFD and numerical optimisation tools in design procedures are investigated.

A deep study focused on cavitation nuclei in particular on their size and velocity has been performed. The scope was getting the higher number of information on this phenomenon whose comprehension seems to be really difficult. To this aim, optical techniques such as PIV and ILIDS, ILIDS being the acronym for Interferometric Laser Imaging Droplet Sizing have been used. This technique uses the same setup of a PIV-2D study, evaluating the size of transparent particles. Until now, its feasibility has been demonstrated especially in sprays of water droplets in air, where an optimal light scattering can be obtained thanks to the values of the relative refractive index and to the spherical shape. The proposed technique would be helpful in research applied to the reduction of greenhouse gas into seawater [7], while in our study we tried to apply it to the air bubbles produced by incipient cavitation in marine propeller wake. Analyzing images respectively at each single frame and in two consecutive ones allows to derive simultaneously bubbles size and velocity.

As a result of the INSEAN activity in the framework of Test 4 of the Contract 07CT09 between Brunvoll AS and INSEAN, the present Report describes the aspects concerning force measurements and cavitation observations around an installed propeller-rudder configuration.

An enhancement of Stereo PIV calibration is presented. The feature of this technique is to calibrate the Stereo system directly from a uniform flow measurement. This is achieved making a first two-dimensional calibration of the measurement plane using a standard dotted target, then getting information of perspective and laser sheet thickness from some measurements of well-known flows (uniform flow). This technique results in three-dimensional measurements of high accuracy with a simple calibration phase and reduces mechanical misalignment and dot recognition errors. A very simple application of this technique is performed in towing tanks. The technique is tested to a tip vortex couple of a submarine bridge fin.

The present Report describes the aspects concerning the experimental activities performed in the framework of the Contract 07CT09 between Brunvoll AS and INSEAN. More specifically, the following tests are documented hereinafter: „h Test 4. Ducted propeller with rudder behind ship hull. Force measurements at non-cavitating and cavitating conditions: - Test 4a. Force measurements at non-cavitating conditions - Test 4b. Force measurements and cavitation observations at cavitating condition „h Test 5. Ducted propeller with rudder behind ship hull. Velocity field measurements at non-cavitating conditions: - Test 5a. Velocity field measurements „h Test 6: Open propeller separated from ship hull. Cavity ordinate measurements - Test 6a. Cavitation tests in straight and oblique flow

As a result of the INSEAN activity in the framework of the Workpackage 4se of the EU-funded "Swirl Jet Study" Research Project, the present Report describes the 2D-PIV experimental campaign addressing the flow field generated by a seabed excavation unit operating within a cavitation tunnel. More specifically the report is arranged according to the following scheme: 1. brief description of the seabed excavation ducted propeller model; 2. overview of the experimental apparatus and set-up used to perform PIV tests at different operating conditions; 3. summary of the main aspects involved in the 2D-PIV images analysis; 4. analysis of the attained results in terms of those flow quantities relevant to the study of the seabed excavation system effectiveness.

As a result of the INSEAN activity in the framework of the Workpackage 2se of the EU-funded "Swirl-Jet Study" Research Project, the present Report describes the aspects concerning the design and construction of the ducted propeller system, as well as the first stage of the experimental activity for the qualification of the swirling jet. More specifically the Report is arranged according to the following scheme: 1. design and construction of the seabed excavation ducted propeller model; 2. measurement of the performance at different operating conditions; 3. wall pressure measurements; 4. visualizations of the jet behaviour. Aims of this experimental activity are to get a preliminary assessment of the behaviour of the swirling jet and to provide recommendations regarding the follow-up test program in Workpackages 4se and 5se.