Experimental Study on Accelerating and Decelerating Ship Motions

Enhancing A Reliable Ship Performance Evaluation in Dynamic Maneuvering Conditions – A Gap Analysis

“…According to Voorde (1974), various wake and thrust deduction fraction properties are derivable only by extensive tank tests of a fully fitted ship model at overload conditions. It refers to propulsion tests at extremely high propeller loadings hence enabling the model to create negative towing forces F and being self-propelled at particular thrust values (MARIN, 1996). Indeed, laborious works were indicated by Harvald (1967) where in some cases tests were executed at lower than the desired speed whilst some others were left out due to time consideration.…”

“…The work further denoted that it seems acceptable to assume both fractions only as functions of the ship speed and propeller thrust magnitudes while independent of the ship speed and propeller loading combinations the thrust achieved. Such a presumption has been proven to be erroneous based on the findings of Harvald (1977Harvald ( , 1967) and experience at Marin (1996). Variation of wake and thrust deduction fraction values plotted as a function of apparent advance ratio J' in the work of Harvald (1977Harvald ( , 1967 have clarified that both fractions are significantly dependent on the ship's speed and the rate of propeller revolution in four quadrant operation.…”

“…Variation of wake and thrust deduction fraction values plotted as a function of apparent advance ratio J' in the work of Harvald (1977Harvald ( , 1967 have clarified that both fractions are significantly dependent on the ship's speed and the rate of propeller revolution in four quadrant operation. Marin (1996) disclosed that despite both fractions being almost independent of the ship's speed, the wake fraction often gradually decreases as the speed increases due to the correlation between the viscous resistance coefficient and the wake fraction viscous component. On the dependency on the propeller loading, it was claimed that both fractions most commonly gradually decrease as propeller loading increases.…”

Study on Stopping Ability of a Ship Equipped with Azimuth Propeller

“…Previous studies on the stopping ability of ships have focused primarily on methods using maneuvering mathematical models (Nakato et al, 1976;Yoshimura, 1994). Recent studies have investigated methods for estimating the stopping ability of full-scale ships using the free-running model test or computational fluid dynamics (Ueno et al, 2017;Sun et al, 2018).…”