Important breakthrough in tests innovative composite screw propeller
PhD candidate Pieter Maljaars and Mirek Kaminski, professor of ship and offshore structures at the Department of Maritime and Transport Technology, have made an important breakthrough in their Greenpop research project. Together with MARIN and the Ministry of Defence, they carried out measurements on a composite screw propeller with a diameter of 1 m, which was designed with Solico and Wärtsilä for one of the Royal Netherlands Navy’s diving support craft. For the first time in history TU Delft and MARIN did a full-scale measurement of the deformations of a composite screw propeller. The quality of the measurements exceeded all expectations. The results of these measurements are extremely important to validate predictions used to design screw propellers. Eventually this can lead to better performance of a ship.
Flexible composite screw propeller
The use of fibre-reinforced plastics in screw propellers is not a new idea, in fact composites are already being used on a highly limited scale in screw propellers. Never before has a composite propeller with such flexible blades been made, however. To maximise the flexibility of the blades, Maljaars optimised the laminate layup of the composite. The blades needed to be highly flexible in order to accurately measure the blade deformations. The ultimate goal is to use the flexibility of composite screw propellers in the future to make better designs. Indeed, the smart use of the blades’ flexibility can improve output and reduce propeller noise. The gained knowledge has been incorporated into the design, production and analysis of the composite screw propeller, thus putting the concrete application of flexible propellers within hand’s reach.
The Greenprop research project’s mission is to develop a validated calculation method that makes it possible to predict the hydrodynamic and elastic behaviour of flexible composite propellers. Greenpop’s extensive validation study aims to illustrate the potential advantages of composite propellers. Subsequently, this knowledge will need to be implemented in practice. More research is needed for that to happen, for example on fatigue and the behaviour of composite propellers in extreme situations. The duration of the Greenprop project is four years, and it is being funded by NWO-Toegepaste en Technische Wetenschappen and the project partners MARIN, the Ministry of Defence, Solico and Wärtsilä.