Accession Number : ADA119800

Title :   Experimental and Theoretical Studies of the Effect of Gas Content on Unsteady Cavity Flows.

Descriptive Note : Final rept. 1 Oct 79-31 Jan 81,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF OCEAN ENGINEERING

Personal Author(s) : Van Houten,Robert J ; Sayre,H Clayton

PDF Url : ADA119800

Report Date : Jan 1982

Pagination or Media Count : 112

Abstract : A partially cavitating two-dimensional hydrofoil was oscillated in pitch while air was bled into the cavity at a controlled rate. By varying the ambient pressure and air flow rate simultaneously, a constant ventilation number was maintained for a series of cavity air partial pressures. Unsteady forces and cavity pressures were measured, and photographs taken. It was found that cavity air caused fluctuating cavity pressures, and tended to stabilize cavity length. Its effect on force coefficients was relatively modest. These trends were also found from a parallel theoretical investigation in which a computer program which predicts unsteady cavitation of 2-D foils was modified to allow for cavity gas. (Author)

Descriptors :   *Hydrofoils, *Cavitation, *Air flow, *Unsteady flow, Constants, Ventilation, Coefficients, Two dimensional, Partial pressure, Pitch(Motion), Computer programs, Predictions, Modification, Experimental data, Gas flow, Oscillation, Flow rate, Variations, Leading edges, Vapor pressure

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE