Accession Number : AD0649746

Title :   PRELIMINARY EXPERIMENTAL INVESTIGATION OF SLAMMING,

Corporate Author : DAVID TAYLOR MODEL BASIN WASHINGTON D C

Personal Author(s) : Szebehely,Victor G. ; Brooks,Samuel H.

Report Date : JUL 1952

Pagination or Media Count : 15

Abstract : The results of experiments performed on a ship model to determine the impact forces on the bottom are analyzed and compared with previous theoretical investigations. It was found that by introducing the concept of equivalent deadrise angle and considering only the first few milliseconds of the impact (i.e., the period of the sudden deceleration), the theoretically predicted acceleration-time curve approximates the experimentally found curve sufficiently well for all practical purposes. On the basis of the few successfully performed experiments, the cautious statement can be made that the speed of advance does not seem to influence greatly either the maximum impact force or the time required to reach maximum deceleration. It is remarkable that the approximate formulae result in good agreement with the experiments performed. The experimental conditions were artificial since the impact was produced by dropping the model at very small (0.1 - 0.2 degree) trim angles. The results of these artificial experiments show very large impact forces. If the actual pitching motion of the ship is considered, the impact forces are much smaller. (Author)

Descriptors :   (*SHIP MODELS, HYDRODYNAMICS), (*WATER WAVES, IMPACT SHOCK), FORCE(MECHANICS), DECELERATION, GRAVITY, MATHEMATICAL ANALYSIS

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE