Verification of Ship Performance Evaluation Method with Onboard Measurement

Abstract

For building and promoting low greenhouse gas emission ships, a design index of ship performance in actual seas is required to be developed. On a project for 10 mode at sea, a calculation method of ship performance in actual seas has been developed. The method can calculate added resistance in short waves with engineering accuracy in terms of correction factors based on tank test results.Onboard measurement is carried out for the purpose of verification of the calculation method. As for onboard measurement, it is difficult to observe encountered waves with accuracy. To avoid the difficulty, wave radar measurement system is applied and measured results are compared with those by other wave measurement systems and the accuracy of wave measurement is discussed.Thereafter, a comparison of calculated ship speeds is made with measured ones with correction by the displacement, engine output,and weather. A procedure for correcting the measured data is described at some length. As a result, it is clarified that the results of onboard measurement show effectiveness of the calculation method.