Gas Diffusion Studies in Steady and Nonsteady Cavities
Abstract
These pages present a study of gaseous diffusion into and turbulent entrainment from steady as well as nonsteady fully cavitating flows and characterize the nonsteady cavity as a dynamic element in a water tunnel test section. An approximate theoretical analysis is done for gaseous diffusion across steady axisymmetric cavities. A comparison with experimental results reveals that the present approximate analysis is suited for better estimates of gaseous diffusion across the gas-liquid interface of axisymmetric cavities than past analyses. Water tunnel experiments for two dimensional flows were conducted on cavities behind a stationary and oscillating flat plate (wedge) hydrofoil. It is found that the steady cavity pressures were significantly higher than the vapor pressure of water and larger cavities tend to maintain higher cavity pressures. Unsteady cavity pressures were found to be significant only at low frequencies of profile oscillation. Downstream and upstream of the cavity, the oscillating cavity was observed to behave like dipole source at low frequencies of foil oscillation. An analysis of the oscillating cavity lengths revealed that for sinusoidal motions of the foil, the first two harmonics of the cavity gas pressure fluctuations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1987
- Accession Number
- ADA185795
Entities
People
- B. R. Parkin
- K. Ravindra
Organizations
- Pennsylvania State University