Quasi-Steady Two-Quadrant Open Water Tests for the Wageningen Propeller C- and D-Series

The Maritime Research Institute Netherlands (MARIN) has recently started a Joint Industry Project (JIP) on controllable pitch propeller (CPP) series called the Wageningen Propeller C- and D-series, after the successful development of the famous Wageningen B-series which are used by designers and engineers worldwide.
The B-series comprise the open water characteristics of conventional fixed pitch propellers (FPPs) designed for merchant ships with various numbers of blades and blade area ratios at different pitch. For several of these propellers, also the four-quadrant characteristics were published by MARIN in the sixties and seventies of the last century.
Today many ships are equipped with CPPs. Also used widely are the ducted CPPs, both for ships and offshore structures. The off-design performance of the CPPs is not only of importance for ships’ powering performance, but also for e.g. dynamic positioning and manoeuvring of those vessels. Due to a lack of systematic information for the CPPs in such cases, the B-series data are often used instead, both for the estimation in an early design stage and also as the final data delivered for specific new CPP designs, simply because there is no other systematic data available rather than the B-series data. However, the characteristics of CPPs differ substantially from those of FPPs. There is a high demand for developing CPP series with full off-design information - the complete twoquadrant open water characteristics at all possible pitch settings.
In order to reduce the cost, a quasi-steady propeller open water test technique has been developed and thoroughly studied under support of this JIP, which reduced the tank test time by a factor of 8 to 10. This method ensures the affordability of the tests for the C- and D-series, and therefore the whole JIP.
In addition to the propeller thrust and torque, the propeller blade spindle torque is also provided as systematic data in propeller series for the first time.