Full-scale performance sea trials of the PressurePoresTM technology

Full-scale URN measurement trials, including propeller cavitation observations, were conducted successfully with the research vessel, Princess Royal, on the North East coast of England in August 2020. The trials involved the testing of two different pressure pores configurations and an unmodified propeller for comparison.

The reduction in cavitation volume was observed through porthole video cameras, and the URN levels of the vessel for each configuration were measured using a traditional hydrophone system with sensors located at 10m, 25m and 45m depth (right). The URN levels were at a range of engine speeds. The trial validated the results of the original CFD and cavitation tunnel studies into PressurePoresTM. 

  • Reductions in URN levels up to a max 10 dB levels were obtained in the 10Hz to 1,000Hz range, for low to medium speeds.
  • Between 700 rpm and 1200 rpm large reductions in cavitation volume were recorded on video for the modified propellers compared to the unmodified.
  • The frequency peaks related to the blade passing frequency (BPF) and its second harmonic (2BPF) at higher speed range displayed a favourable decrease in amplitudes with increasing number of pores.