Propulsors & Cavitation
The Propulsors and Cavitation Team is specialized in ship propulsors, including the interaction with the aftbody of the ship and Energy Saving Devices (ESDs). The full range of propulors is addressed, such as screw propellers, water jets, pump jets, and fin propulsion. Propulsors are designed for both high efficiency and low noise, reducing propeller-induced hull-pressure fluctuations to a minimum, while avoiding erosive cavitation. Increasing demands tend to be imposed with regard to the radiated noise level of the propulsor, further limiting the design space. For surface combattants, the propulsor & cavitation team focuses on designing propellers with the highest possible cavitation speed and a reduced signature. Cavitation on rudders and struts is studied as well.

Propeller designs or propeller analyses are among the most requested services from the Propulsors and Cavitation Team. Much of the knowledge of the team is collected from over 70 years of propeller design experience, and the participation in a number of multi-client research and development projects (JIPs, CRS). Apart from the “conventional” propeller design, the team is involved in a number of development projects for new propulsor types, almost all of them striving for higher efficiencies combined with an acceptable cavitation behaviour.

Propeller designs are made using the full range of available design and analysis tools, such as lifting line programs, boundary element menthods, and RANS codes. The RANS codes are used for wake prediction as well as propeller analysis. A computational cavitation analysis is part of each propeller design evaluation. Propeller testing is optionally advised, depending on the constraints of the ship-propeller design.

MARIN uses two test facilities for cavitation resarch. The Depressurised Towing Tank is used for most projects, where propellers are tested for cavitation, ventilation, and noise at precisely-scaled conditions . The Cavitation Tunnel is used for applied cavitation research.



Propulsors and Cavitation expertise
MARIN's propulsors and cavitation expertise embodies:

  • Consultancy on the physics of various propulsors types and cavitation.
  • Designing of screw propellers with a high efficiency, delayed or good cavitation behaviour, low noise and high-inception speeds.
  • In-house potential and viscous flow codes, which are being developed continuously through our R&D effort, contributing to the understanding of local flow phenomena, sub-system optimisation, investigations and calculations of scale effects, understanding of underlying physics of flows, cavitation, etc.
  • Analysing and evaluating cavitation observations performed in our basins.
  • Interpretation of propeller-induced hull-pressure fluctuations and radiated noise, linked to the observed cavitation behaviour.
  • Interpretation of cavitation erosiveness
Contact
Phone +31 317 49 34 72
E-mail ships@marin.nl

The Propulsors and Cavitation Knowledge Team is headed by:

Prof. dr. ir. Tom van Terwisga,<br>Propulsors and Cavitation Knowledge Coordinator Prof. dr. ir. Tom van Terwisga,
Propulsors and Cavitation Knowledge Coordinator
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