Some aspects of the research into propeller induced vibrations 1

Abstract

A review is given of the various types of excitation due to the propeller and the engine.

Experimental results of the excitation forces are discussed and compared with theoretical analysed values.

An accurate theoretical approach for the calculation of these excitation forces, giving a more satisfactory agreement, is being developed.

The excitation of the propeller on the shaft can be split up into an axial and a lateral part. The theoretically or experimentally determined axial excitations (thrust and torque) are dealt with in more detail, and used as a basis for the prediction of the full size thrust and torque fluctuations and vibratory motions.

Problems, concerning the instrumentation for the measurement of the propeller induced hull excitations, are discussed.

The analysis of the lateral vibrations of the propeller shaft (whirling) must be combined with the hull vibrations. Interactions are given in a diagram.

Finally the present limitations of the analysis are stated and an outline of the future research in order to come to a reliable design stage prediction technique of the hull and shaft vibrations is given.