Propeller induced pressure fluctuations and noise as well as cavitation are investigated by means of measurements and high speed video observation. Propeller shaft and single propeller blade forces and moments can be measured using advanced in-house developed miniaturized instrumentation, in addition to standard thrust and torque measurements.
The flow around two- and three-dimensional bodies can be studied by means of stereo particle image velocimetry (S-PIV), while deformations of hydro elastic structures are measured with stereo digital image correlation (S-DIC).
Typical services:
- Cavitation observations, documentation, pressure pulses and noise measurements of propellers in open water and behind a model
- Open water tests of conventional , ducted and azimuthing propellers (and duct) in axial and oblique flow
- Flow field measurements by Particle Image Velocimetry (PIV), Laser Doppler Velocimentry (LDV) and Pitot racks
- Evaluation of performance of air lubrication systems
- Evaluation of performance of antifouling coatings
- Measurement of the shape of hydroelastic objects by Digital Image Correlation (DIC) and strain gauges
- Measurement of hydrodynamic performances of flow exposed objects
SINTEF's standard procedure for propeller cavitation testing in behind condition, is to use aftbody model and simulation of estimated full scale wake distribution, based on the measured wake distribution in the towing tank.
Cavitation tunnel data:
- Length of test section: L = 6m.
- Cross section dimensions: W 1.3m x H 1.2m.
- Maximum water velocity: 10 m/sec.
- Maximum working pressure: 2.5 atm.abs.
- Minimum working pressure: 0.2 atm.abs./sv~0.2.
- Impeller motor power: 1150 kW.
- Open water dynamometer, thrust = +- 1000 N, torque = +- 55 Nm.
- Boat dynamometer thrust = +- 1000 N, torque = +- 50Nm