Accession Number : AD0730783

Title :   Constant Thrust vs. Constant Velocity Method for Resistance Measurement in Waves,

Corporate Author : CALIFORNIA UNIV BERKELEY COLL OF ENGINEERING

Personal Author(s) : Sibul,O. J.

Report Date : JUN 1971

Pagination or Media Count : 36

Abstract : Constant thrust and constant velocity methods of towing for the resistance measurement of ship models in waves were compared in irregular waves of four different spectral content. The results indicate that there is no difference in results between the two methods. This is very encouraging, because the constant velocity towing is very much easier to perform, and the results are more reliable and accurate. A new constant velocity dynamometer was designed and built so that the periodic forces, caused by the orbital velocities in waves, and the net horizontal force can be separated. This is done by integration. The average slope of the integrated dynamometer output curve represents the net horizontal force. (Author)

Descriptors :   (*SHIP HULLS, *DRAG), WATER WAVES, THRUST, VELOCITY, MEASUREMENT, DYNAMOMETERS, MODEL TESTS

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE