Test performed in KHRC free-surface cavitation tunnel T-31. The Thruster/POD-housings are fitted around a gear unit which provides momentum to the propeller from an electric motor. The gear unit is set up in a test-rig with a flat plate representing the hull plating. A piston controls the azimuth angle of the unit (±15 deg).
Propeller thrust and torque are measured using a dynamometer between the gear unit and the propeller hub. Total unit thrust is measured using a 5-axis dynamometer, placed between the Thruster/POD unit and the drive mechanism.
Propeller thrust/torque and unit forces are measured at a range of different advance numbers (J) and cavitation numbers (σ) by changing the shaft speed and tunnel pressure at constant water velocity.
A full set of tests comprise of:
Force measurements, propeller and unit efficiency
Cavitation observations and inception test (propeller and unit) at different azimuthing angles.