Standards for environmental impact, safety and operational performance of ships are becoming increasingly strict. In order to meet these standards, the new ship designs must be predicted with an increasing level detail confidence. As present prediction methods lack realistic, dynamic behaviour ship's propulsion plant, there is a need more advanced methods. this paper, open water test Hardware i...

The necessity to improve the hydrodynamic performance of marine vessels has confirmed urgency conducting further investigations on biomimetic tubercles. In this work, towing tank tests were conducted at a range speeds conveniently prepared flat plates coated with 3D printed humpback whales mimicked results showed that artificial tubercles induced drag reduction up 1.3% compared bare plate. Foll...

This paper introduces an autonomous towed vehicle which has various navigation modes; towed mode, autonomous mode and kite mode, to stand against fast and changeable sea currents. The property assures safe and reliable observation works irrespective of a current speed. Such vehicle must be useful for port area application since in a port area sea currents are so fast and complex. The different ...

A contra-rotating marine current turbine has a number of attractive features: near-zero reactive torque on the support structure, near-zero swirl in the wake, and high relative interrotor rotational speeds. Modified blade element modelling theory has been used to design and predict the characteristics of such a turbine, and a model turbine and test rig have been constructed. Tests in a towing t...

Hydraulic turbine discharges in low-head hydroelectric plants, and plants with awkward intake geometries can be measured relatively easily with the Acoustic Scintillation Flowmeter (ASFM). The ASFM is non-intrusive, and may be deployed in intake gate slots in a straightforward manner, lending itself to multiple measurements in the same plant. Examples of measurements in two generating stations ...

An experimental investigation has been carried out to document and relate the frictional resistance and roughness texture of painted surfaces smoothed by sanding. Hydrodynamic tests were carried out in a towing tank using a flat plate test fixture towed at a Reynolds number ~ReL ! range of 2.8310 25.5310 based on the plate length and freestream velocity. Results indicate an increase in friction...

An experimental study has been made to compare the frictional resistance of several ship hull coatings in the unfouled, fouled, and cleaned conditions. Hydrodynamic tests were completed in a towing tank using a flat plate test fixture towed at a Reynolds number ~ReL! range of 2.8310 6 – 5.5310 based on the plate length and towing velocity. The results indicate little difference in frictional re...