LOW FRICTION PROPULSION BY MEANS OF BOUNDARY LAYER CONTROL
The propulsion resistance of ships is composed of wave resistance and frictional resistance. The former is being minimized by matching bow section, stern section, and length of parallel middle body and-more recently-by addition of bulbous bows etc. Accordingly frictional resistance is for many vessels an important part of the total. The frictional resistance refers to the ship's boundary layer only. For many years ship model basins have applied various boundary layer control methods to stimulate the transition from laminar to turbulent flow along the ship model in order to simulate what actually occurs on full-scale ships. This transition increases the frictional resistance of ships by a factor of about 10 whereas in the field of aeronautics various principles are utilized in order to prevent this transition from taking place. This paper deals with a system design and a cost/benefit analysis of boundary layer control by bleeding. The volume of water drained from the boundary layer which surrounds a ship is continuously discharged into the upper part of the ship wake to adapt the flow to the propeller and thus, in addition to saving power, reduce vibration pressures on the hull. Segregated oil tank ships lend themselves well to the system, which could be a means of obtaining high fuel economy in the tankers of the 80's.
- Paper presented at SNAME (Gulf Section) Spring Meeting and Star Symposium: Merchant & Naval Design, The Past in Review The Future in Forecast, Houston, April 25-28, 1979.
Society of Naval Architects and Marine Engineers601 Pavonia Avenue
Jersey City, NJ United States 07306-2907
- Kure, K
- Fog, J
- Publication Date: 1979
- Features: References;
- Pagination: 12 p.
- TRT Terms: Analysis; Ballast (Ships); Boundary layer; Costs; Economic analysis; Engine efficiency; Fluid resistance; Fuel conservation; Fuel consumption; Hulls; Laminar flow; Propellers; Propulsion; Ship motion; Ships; Skin resistance; Tankers; Turbulence; Turbulent boundary layer; Wakes; Wave resistance
- Uncontrolled Terms: Cost analysis; Hull resistance
- Old TRIS Terms: Boundary layer control; Laminar boundary layer; Propeller wake; Propulsive efficiency; Segregated ballast tankers
- Subject Areas: Design; Economics; Energy; Finance; Marine Transportation; Vehicles and Equipment;
- Accession Number: 00189654
- Record Type: Publication
- Source Agency: Society of Naval Architects and Marine Engineers
- Files: TRIS
- Created Date: Apr 25 1979 12:00AM