PARTIAL FORM FACTORS FROM EQUIVALENT BODIES OF REVOLUTION FOR THE FROUDE METHOD OF PREDICTING SHIP RESISTANCE
The role of partial form factors is described in improving the Froude method of extrapliating the resistance measurements of ship models to full-scale conditions. "Partial form factors" convert the equivalent flat-plate resistance into the part of the viscous resistance of ship hulls which varies with Reynolds number. In contrast, "whole form factors," sometimes called Hughes form factors, convert the equivalent flat-plate resistance into a viscous resistance which varies completely with Reynolds number. The use of a partial form factors results in a full-scale resistance less than that predicted by the traditional method of zero form factor and greater than that predicted by the whole form factor (Hughes) method. It is advocated that partial form factors tailored to the particular ship be obtained from boundary-layer calculations of the viscous resistance of equivalent bodies of revolution. Some numerical examples are given and a rough correlation of calculated partial form factors with hull geometry is also presented.
- Presented at the First Ship Technology and Research (STAR) Symposium, Washington, D.C., August 26-29, 1975.
Society of Naval Architects and Marine Engineers601 Pavonia Avenue
Jersey City, NJ United States 07306-2907
- Granville, P S
- Publication Date: 1975-8
- Features: References;
- Pagination: 8 p.
- TRT Terms: Bodies of revolution; Fluid resistance; Hulls; Resistance (Mechanics); Viscosity; Wave resistance
- Uncontrolled Terms: Hull resistance
- Old TRIS Terms: Model ship correlation; Viscous resistance
- Subject Areas: Design; Marine Transportation;
- Accession Number: 00126937
- Record Type: Publication
- Source Agency: Society of Naval Architects and Marine Engineers
- Report/Paper Numbers: #9
- Files: TRIS
- Created Date: Nov 5 1975 12:00AM