Accession Number : AD0725171

Title :   Investigation of Water Impact of Blunt Bodies.

Descriptive Note : Final rept. Nov 66-Dec 70,

Corporate Author : SOUTHWEST RESEARCH INST SAN ANTONIO TEX DEPT OF MECHANICAL SCIENCES

Personal Author(s) : Gerlach,C. Richard ; Astleford,William J.

Report Date : DEC 1970

Pagination or Media Count : 87

Abstract : The report summarizes results of an experimental study to determine the influence of hull form, water surface state, and elasticity of a model bottom on the peak pressures experienced by a body impacting on a water surface. Three two-dimensional models were constructed having section shapes of a U, UV, and V form, but identical extent of flat bottom. Drop tests were performed on still water and on waves, and impact pressure data was obtained at several locations on the bottom of each model. For impacts on still water, the peak pressure varies in a complex fashion as a function of basic shape, mass loading, and extent of flat bottom. For impacts on waves, the pressure values are quite random for subsequent drops, and the average value for a large number of samples is greatly reduced from the still water pressure value. It is concluded that the impact mechanism for waves is quite different from the still water impact condition, and the wave data correlates well with model seaworthiness test results. The effect of bottom elasticity is observed with regard to the peak impact pressure. Work hardening of the elastic bottom is related to the cushioning effect, in which the peak pressure increases for subsequent drops. (Author)

Descriptors :   (*SHIP HULLS, IMPACT SHOCK), (*OCEAN WAVES, IMPACT), BLUNT BODIES, MODEL TESTS, ELASTIC PROPERTIES, HYDRODYNAMIC CONFIGURATIONS, NAVAL RESEARCH, HYDRODYNAMICS, SURFACE PROPERTIES, PRESSURE

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE