Success of renowned ‘Wageningen B’ followed by the future-ready C & D-Series


A three-year JIP leads to 35 new, open and ducted Controllable Pitch Propeller (CPP) designs after a test programme involving more than 750 open water tests. Henk van den Boom & Jie Dang, h.v.d.boom@marin.nl


T


he results from a new series of open and ducted CPPs have recently been implemented in a practical,


designers’ software. The software enables propeller manufacturers and naval architects to customise design propellers and to derive geometry and thrust/torque characteristics, as well as blade spindle torque for arbitrary design cases.


Many ships and offshore vessels are equipped with open or ducted CPPs, which are used for navigation and dynamic positioning (DP). For these types of propellers, not only the thrust-power performance over the complete rpm/speed range is of importance, but also the blade spindle torque. However, until now no systematic data has been available for CPPs.


15 pitch settings Based on the success of the well-known Wageningen B-series,


MARIN initiated the Wageningen C&D Propeller Series JIP three years ago. With the support of leading CPP designers and manufacturers worldwide, an extensive systematic series of contemporary design propellers were developed. In total, 20 open and 15 ducted CP propellers were designed. The series comprises four and five bladed propellers with blade area ratios ranging from 40% to 75%. The D-propellers are combined with both duct No. 19A and No. 37. Each propeller with a specific design pitch was tested at more than 15 different pitch settings. In total the test programme thus comprised more than 750 open water tests.


As conventional open water tests would require more than two years work in the towing tank, a new quasi-steady testing technique was developed. During one run


the speed is varied at constant rpm, whereas in a second run the rpm is varied at constant speed. From these two runs the full propeller characteristics and blade spindle torque is derived for each pitch setting. The results from the quasi-steady and conventional open water tests concurred well. The test results were processed to generate the open water diagrams for all quadrants and these were delivered to all participants, both in tabular and graphical form. Results showed that the new propellers perform well; often better than the B-series fixed pitch propellers.


MCD software The abundance of data produced in the JIP requires a dedicated tool which provides practical access for naval architects and propeller designers. To this end, MARIN developed and delivered the MCD software in an extension of the JIP. The function of the software includes:


Final participants meeting hosted by MAN in Frederikshavn, June 2015 26 report


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