Dipl. Math. Julia Dohmen, B.Sc. Erwin van Heumen, Dipl.-Ing. Klemens Hitzbleck

Determination of design loads for the structural design of ship propellers: PROPSEAS

The influence of ship  motions in seaways on propellers and the stress resulting from manoeuvring processes have not been recorded in a way that would allow load spectra to be determined for the dimensioning of the propeller‘s structure.

In recent years, propeller designs have changed notably. In addition, podded drives have increasingly found their way into the design of even the largest ships. For these new developments, experimental data are lacking as yet.

Within the framework of the European joint project “Propulsion in Seaways”, procedures and methods are aimed to be developed to create load spectra for propellers on the basis of the operational profile, the conditions of sea in the cruised area and the typical manoeuvring situations. For this purpose, strain gauges are installed at a propeller of an offshore supply vessel. The stresses working on the propeller are recorded along with the motor power and the ship motions. Based on these data, a load spectrum can be drawn up for the ship examined and similar ones. The loads affecting the propeller are determined on the basis of the sea state and the geometry of the ship by using numerical methods as well. The results of these calculations are validated on the basis of the full-scale measurements and model tests. From the results of the mea-surements, model tests and simulations, guidelines and recommendations are to be derived by which propellers can be reliably dimensioned for different design loads.

Project partners for this project in Germany are Develogic GmbH and Germanischer Lloyd AG and in Norway the research centre MARTEC, Norwegian University of Science and Technology, Rolls-Royce Marine AS and Farstad Shipping ASA.

Partners of this project in Germany are: University of Hamburg, Develogic GmbH, Germanischer Lloyd AG. In Norway: Research Centre MARINTEK, Norwegian University of Science and Technology, Rolls-Royce Marine AS and Farstad Shipping ASA.