EXPERIMENTAL DETERMINATION OF THE FORCES ON SUPERCAVITATING HYDROFOILS WITH INTERNAL VENTILATION,
Abstract
An investigation is in progress to develop techniques for using internal ventilation to produce very low cavitation numbers at low and moderate speeds. A nondimensional coefficient, the ventilation index, was defined. It was found that the cavitation number based on measured cavity pressure behaves differently for ventilated flows at speeds in the supercavitating regime and at speeds in the subcavitating regime. In both cases, however, the measured cavitation number is related directly to the ventilation index and is relatively insensitive to angle of attack. At high values of the ventilation index (about 0.19 for tests of the 5-term foil reported), the lift and drag coefficients become constant at values appropriate to zero cavitation number. Methods for relating the lift and drag coefficients for various ventilating airflow rates to the appropriate cavitation number are presented for the two speed ranges. Discrepancies exist between the results obtained from high- and low-speed ventilated tests. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1963
- Accession Number
- AD0615032
Entities
People
- G. F. Dobay
- N. L. Ficken Jr.