Wind and current correction methods for speed trial analysis of ships

Abstract

This paper presents theoretical treatments of the external disturbance correction due to wind, tidal current, etc. for the speed trial analysis. Basic equations are presented for the external disturbance correction. By solving the equations, the true relation in ship speed, propeller revolution and delivered power after reducing the external disturbance effects is captured. To validate the present methods, virtual speed trial data is theoretically generated for certain external disturbance conditions and the present method is applied to eliminate the external disturbance effects from the virtual speed trial data. The obtained results are compared with true answer. As a result, the present methods are useful for the external disturbance correction for cases where the current velocity variation is small with respect to the time required for a trial.