Performance of dynamic azimuthing podded propulsor

This paper presents results and analyses of an experimental study into the effects of static and dynamic azimuthing conditions on the propulsive characteristics of a puller podded unit in open water. The model propulsor was instrumented to measure thrust and torque of the propeller, three orthogonal forces and moments on the unit, rotational speed of the propeller, azimuthing angle and azimuthing rate. The model was first tested over a range of advance coefficients at various static azimuthing angles in the range of-180° to 180°. These tests were followed by tests in which the azimuthing angle was varied dynamically at certain azimuthing rate and propeller rotational speed. A comparative study of the performance coefficients at static and dynamic azimuthing conditions in the range of-180° to 180° is presented. The performance coefficients of the propeller and the pod unit showed a strong dependence on the propeller loading and azimuthing angle. The coefficients in static azimuthing conditions fit well with a 10th order polynomial fit of the data obtained in the dynamic azimuthing condition in the corresponding azimuthing angles and advance coefficient. An uncertainty analysis of the measurements is also presented. © 2012-IOS Press and the authors.