Accession Number:

AD0260436

Title:

SHIP RESISTANCE AND MOTIONS IN UNIFORM WAVES AS A FUNCTION OF BLOCK COEFFICIENT

Descriptive Note:

Corporate Author:

CALIFORNIA UNIV BERKELEY WAVE RESEARCH LAB

Personal Author(s):

Report Date:

1961-06-01

Pagination or Media Count:

1.0

Abstract:

A series of experiments were performed to study the effect of block coefficient and the wave steepness on the added resistance of ships in uniform waves. Five-foot models of Series 60 with block coefficients 0.60, 0.70, 0.80, and a destroyer model with a block coefficient of 0.492 were chosen. The models were towed in waves five feet long at wave steepnesses varying between 168 and 114. Still water resistances were measured in separate experiments and the added resistance due to the oncoming waves derived by subtracting the still water resistance from the total resistance in waves. Heaving and pitching motions were measured and the bow submergence and emergence estimated for each case. The results indicated that the added resistance depends upon the block coefficient, the speed of the ship, and the steepness of the waves. It has a maximum in the vicinity of the maximum motions and decreases again for the higher speeds. The added resistance reaches higher values per unit displacement for smaller block coefficients. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE