Accession Number : AD0499889

Title :   Inception of Cavitation on Hydrofoil Systems.

Descriptive Note : Technical rept.,

Corporate Author : BATH IRON WORKS CORP ME*

Personal Author(s) : Hoerner, S. F.

Report Date : AUG 1952

Pagination or Media Count : 42

Abstract : This report is concerned with the inception of cavitation in flows about bodies pertinent to hydrofoil systems. The basic phenomenon of cavitation is first discussed with respect to the influence of air content, time of exposure to low pressures, and separated flows. Minimum pressures on airfoils are related to the thickness and lift coefficient; empirical relations involving these parameters are determined which are applicable to a large class of hydrofoil shapes. The use of critical Mach numbers in determining inception values of the cavitation index, particularly for interference flows, is discussed. Cavitation data for several forms of blunt bodies are given. Considering surface roughness elements as blunt bodies, an approximate method of predicting the inception of cavitation on roughness elements in a boundary-layer flow is presented. An empirical formula is derived for the critical speed of hydrofoils and broad conclusions deduced from this study are stated.

Descriptors :   *HYDROFOILS), (*CAVITATION, HYDRODYNAMICS, BLUNT BODIES, AIRFOILS, FLUID FLOW, FLOW SEPARATION, VELOCITY, AIR, DRAG, LIFT, BOUNDARY LAYER, PRESSURE, THICKNESS, ASPECT RATIO, MACH NUMBER, SURFACE ROUGHNESS.

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE