THE PERFORMANCE OF A FULLY SUBMERGED PROPELLER IN REGULAR WAVES
Abstract
The performance of a 16-in., 6-bladed propeller in waves was determined experimentally, and the records of the time-dependent fluctuating propeller forces are analyzed. Various wave lengths, wave heights, and frequencies of encounter were investigated with the propeller advancing normal to the wave crests at each of two fixed shaft centerline submergences. The results indicate that the orbital velocities of the waves have a significant effect, causing fluctuations of the advance coefficient and corresponding fluctuations of the thrust and torque coefficients. The local advance coefficients have been determined by calculating the mean orbital velocities of the waves in way of the propeller disk from trochoidal wave theory. The thrust and torque coefficients for the propeller when operating below wave crests and wave troughs were plotted against their local advance coefficients, and the results were in good agreement with the open-water characteristic curves for the propeller in uniform flow. It is concluded that the performance of a propeller in waves may be predicted from a q quasi-steady state analysis.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 31, 1961
- Accession Number
- AD0259814
Entities
People
- G. L. Ober
- J. H. Mccarthy
- W. H. Norley