Published on January 20, 2016
1. BACKGROUND • The use of “air lubrication” has been the goal of naval architects for many years (patents from the 1800’s). • “Stepped Hulls” have been employed on planing craft and amphibious aircraft since the 1920’s. • But, gas injection for drag reduction has found practical application on some high speed moving vehicles. • And, its use on surface ships is under active development.
2. POTENTIAL DRAG REDUCTION BENEFITS INCREASED SHIP PERFORMANCE REDUCED FUEL USAGE AND COST REDUCE CO2 AND OTHER EMISSIONS (NOX AND SOX)
3. BUBBLE DRAG REDUCTION(BDR) AIR LAYER DRAG REDUCTION(ALDR) PARTIAL CAVITY DRAG REDUCTION(PCDR)
4. FUTURE PROJECTS Air lubrication system Bubbles generated by blower reduce the frictional resistance between the vessel’s bottom and the sea water. Estimated CO2 Reduction : 10% Already installed on heavy lift vessels YAMATAI built by Mitsubishi Heavy Industries. Will also undergo verification tests on a bulk carrier. C/O MHI M/V Yamatai, M/V Yamato Length overall: 162.0m Beam: 38.0m Max. draught: 6.34m Gross ton: 14,538GT Deadweight: 19,500 DWT
5. FIRST PHASE (14 Jan 16-04 Feb 16) Methods and concept understanding (14 Jan-22 Jan) Techniques of ALS (27 Jan-31 Jan) Feasibility of retrofitment on existing ships (01 Feb- 04Feb) Application in new ships (23 Jan-26 Jan)
6. SECOND PHASE (06 Feb 16-27 Feb 16) Calculation of drag percentage reduction on a conventional ship (06 Feb-12 Feb) Basic CFD studies on the hull (23 Feb-27 Feb) Empirical methods based on studies carried out (17 Feb- 22Feb) Calculation of resistance components on a vessel fitted with ALS (12 Feb-16 Feb)
7. THIRD PHASE (28 Feb 16-18 Mar 16) Cost benefit analysis (28 Feb-04 Mar) Life cycle cost estimate (14 Mar-18 Mar) Proposed cost for installation, operation and maintenance of the system (09 Mar- 13Mar) Energy saving calculation (05 Mar- 08Jan)
8. FOURTH PHASE (19 Mar 16-31 Mar 16) Carrying out calculation on a warship- LIVE PROJECT
... Drag reduction; Air lubrication; Air layer; ... usually through a slot, porous material or a ... ρg,1 is the initial density of the gas to be ...
Lubrication Drag reduction Dimple Bubble Meniscus force. 1 Introduction. Many scholars conducted much research on drag reduction using dimples on a surface.
The Mitsubishi Air Lubrication ... will realize a 10 percent reduction in CO2 emissions through the ... get turbulence that adds to the drag.
Aerosols An aerosol is a ... moving at velocity Uoo through a stagnant fluid. The total drag force exerted by ... projected into still air at 298 K with an ...
Hydrodynamic lubrication ... Fluid bearing "pads" often have to be used in ... The fluid film of the bearing is air that flows through the bearing ...
Decreasing frictional resistance by air lubrication on ... of air injection: Bubble Drag Reduction (BDR ... the gap through a needle at ...
Lubrication is the process or ... phenomenon where reduction of friction ... the fluid to flow through. Much as in hydrodynamic lubrication, ...
The force on an object that resists its motion through a fluid is called drag. ... it is called aerodynamic drag (or air ... has any initial horizontal ...
A consideration on drag reduction by air lubrication using integral type boundary layer computation
This difference creates a backward force called pressure drag. ... a shape that slips through the air more smoothly and helps reduce pressure drag. ...