Design of research vessels; propeller cavitation and bubble sweep down in operational conditions
Author Gert-Jan Zondervan, Patrick Hooijmans, Gerco Hagesteijn en Teunis Huisman
Title Design of research vessels; propeller cavitation and bubble sweep down in operational conditions
Conference/Journal 13th International Symposium on Practical Design of Ships (PRADS), Copenhagen, Denmark
Paper no. ID157
Month September
Year 2016

Abstract
A critical aspect in the operation of special purpose research vessels is the interference by the flow over the hull and propel-lers with acoustic sensors. Low noise propellers are designed for these vessels that have delayed cavitation inception char-acteristics allowing the propeller to operate free of cavitation for a specified operational speed range. These propellers are often designed and tested on model scale for ideal trial condi-tions. In reality, however, the low noise characteristics of the ship and propellers are substantially influenced by the opera-tional conditions that the ship experiences. Serious downtime is for example to be experienced when the sonar equipment is disturbed by air bubbles. In this paper first an overview and discussion is made on the approach in low noise propeller design and the effect of oper-ational conditions on the design. It is further shown how model tests in waves carried out in a depressurized towing tank provide valuable insight in the performance of the pro-pellers in operational conditions. Furthermore, other typical issues such as bubble sweep down as a source of malfunction-ing of the echo sounders can be investigated.

   Subject to copyright regulations
Disclaimer | print