Experimental investigation of the influence of hub taper angle on the performance of push and pull configuration podded propellers

The influence of propeller hub taper angle and mode of operation on open water baseline and podded propeller performance have been experimentally evaluated for push and pull mode propellers with 15° and 20° hub taper angles. Results from two series of experiments considering performance with and without the presence of the pod and strut geometry are presented.; Discussions of the testing methods used for 'propeller only' tests and 'podded propeller unit' tests have been provided. Limitations of these methods are included and test procedures to evaluate the influence of fairing adapters on 'propeller only' results are suggested.; The effect of hub taper angle on both 'propeller only' and 'podded propeller unit' performance are provided along with suggestions of how these findings may be used to better adapt propeller designs to the operational profile of the vessel.; Variation in performance as a function of mode of operation is described, along with discussion of potential causes of observed differences. Recommendations are provided to guide future research in this area.; Experimental uncertainty analysis methods and results are detailed for both 'propeller only' tests and for 'podded propeller unit' tests. Approaches to reduce uncertainty levels in future experiments are suggested.