Abstract Authors continued to develop and expand new experimental methodology on tank model test with the MDES (Marine Diesel Engine Simulator) and the ATS (Auxiliary Thruster System), for making evaluation techniques on actual ship performance in waves more sophisticated. In this fourth report, the methodology is so enhanced that measured results of model test can be directly evaluated as the actual ship performance in waves. Here, the details of the newly expanded methodology are introduced, and experimental results measured from the free running model tests in waves with the expanded methodology are validated, even focusing on behaviors of ship diesel engine.

Abstract The experimental methodology for Self-Propulsion test with a MDES (Marine Diesel Engine Simulator) is expanded by a newly developed Auxiliary Thruster System. The MDES controls propeller rotational speed, by measured propeller torque and rotational speed itself as inputs, with control algorithm reflecting the marine diesel engine characteristics. Here, with auxiliary and adjustable force equaling to Skin Friction Correction on a model ship even in free running experiment, we can make propeller loading condition of model ship corresponded to that of actual ship at same Froude number. Authors developed an Auxiliary Thruster System (hereafter, ATS) whose thrust force is controllable. Then, adding the force equaling to Skin Friction Correction by the ATS, the experimental methodology with the MDES will be upgraded, because propeller torque input to the MDES are greatly approached to that corresponding in actual ship. In this study, free running model experiment in waves using the MDES and ATS were conducted, and there are significant differences between the results with and without the ATS. Furthermore, a problem on the methodology with the MDES and ATS are discussed.

ABSTRACT Controllable pitch propeller, CPP, is added to the experimental methodology for self-propulsion model test in waves with the MDES: Marine Diesel Engine Simulator. MDES is a real-time control system of propeller rotating speed reflecting the characteristics of marine diesel engine. The authors (Tanizawa, Kitagawa, Takimoto and Tsukada, 2012) introduced MDES, presented the model test results in waves and proposed the new experimental methodology to measure ship performance in waves. Using this methodology, we can measure not only ship motion responses but also the realistic dynamic responses of ship propulsion system in waves such as propeller load, rotating speed fluctuation and fuel supply rate of main engine and et cetera. As one of the additional functions of the methodology, the authors developed a model of controllable pitch propeller, CPP. This model CPP is driven by MDES and the transient response of engine to the variation of pitch angle can be reproduced. Using this model CPP and MDES, the authors conducted self-propulsion model test in waves at Actual Sea Model Basin of NMRI. This paper introduces the outline of the model CPP and result of the experiment.