Accession Number : AD0430179


Title :   An Experiment Concerning Partly Closed Cavities Behind a Surface-Piercing Rod


Corporate Author : CALIFORNIA INST OF TECH PASADENA HYDRODYNAMICS LAB


Personal Author(s) : Meijer, M. C.


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/430179.pdf


Report Date : JAN 1964


Pagination or Media Count : 31


Abstract : The post-base ventilation state, as described by P. Thomsen in TRG, Inc., report 156 SR-2, did not occur in the free surface water tunnel in a natural manner. It could be obtained by partial closure of the gap in the water surface with a plate. Removal of this plate resulted always in a restoration of the original base ventilated state if the velocity was high enough. It seems reasonable to suppose that in the case of A. D. Hay's experiments (Flow About Semi-Submerged Cylinders of Finite Length, Princeton U., 1 October 1947) such a plate or other spray cover near the surface must have been present, which became effective at high velocities, when the spray sheet could make good contact with it. At the transition of the pre-base ventilation state and the base ventilation state, stable cavities did exist which were nearly closed near the water surface, or at a lower point. (Author)


Descriptors :   *CAVITIES , *SURFACE WATERS , *SEMISUBMERGED , AIR , VACUUM , BUBBLES , WAKE , DRAG , HYDRODYNAMICS.


Subject Categories : FLUID MECHANICS


Distribution Statement : APPROVED FOR PUBLIC RELEASE