Propeller Tests

In the laboratorytests on model propellers measuring 40cm in diameter and smaller, are conducted both in open water and in the wake of ship models, adhering to the procedures outlined by the International Towing Tank Conference (ITTC).

Propeller open water tests

In propeller open water tests, performance measurements of model propellers are carried out using a propeller open water dynamometer. Thrust and torque values are measured, and propeller open water diagrams are obtained by changing the flow rate and the speed of the propellers in the cavitation tunnel test section.

Propeller tests behind the ship model (Cavitation observation and noise measurement)

A standard propulsion dynamometer or contra-rotating propeller dynamometer is used during the experiments in which the propeller is tested behind the ship model. Performance and noise measurements of model propellers and cavitation observations can be made. The pressure inside the cavitation tunnel is changed in a controlled manner to establish flow similarity between the full-scale ship and the model.

In the cavitation observation tests, a pair of stroboscopes is utilized to observe cavitation at various angular positions of the propellers. Continuous light sources and a high-speed camera are employed during cavitation observations to conduct real-time imaging and capture recordings for subsequent detailed examinations. For noise measurement tests, a set of broad-spectrum hydrophones is deployed to measure background and total noise levels. Ongoing research focuses on implementing a measurement mechanism within the cavitation tunnel to mitigate errors arising from finite volume and reverberation.