16-02-2010, 09:44 AM
ABSTRACT
DRAG REDUCTION
Whatâ„¢s Drag?
Drag is a mechanical force generated by a solid object moving through a fluid.
Forces Acting are :-
Frictional resistance
Wave making resistance
Air resistance.
Whatâ„¢s Microbubble?
Microbubbles is a drag reduction device that reduces skin friction of a solid body moving in water by injecting small bubbles into the turbulent boundary layer developing on the solid body.
Applications
Itâ„¢s application is confined to the ships, especially large ships. Ships such as tankers play a major role in marine transportation.
Conclusion
The near-wall concentration of the bubbles is an important factor and when this drops to a low level the drag reduction effect is diminished or eliminated. This indicates that the interactions of the bubbles with the near-wall turbulence are critical.
Smaller bubbles in general are more effective in reducing drag.
At higher Reynolds numbers the range of bubbles sizes may be effective in reducing drag.
DRAG REDUCTION
Whatâ„¢s Drag?
Drag is a mechanical force generated by a solid object moving through a fluid.
Forces Acting are :-
Frictional resistance
Wave making resistance
Air resistance.
Whatâ„¢s Microbubble?
Microbubbles is a drag reduction device that reduces skin friction of a solid body moving in water by injecting small bubbles into the turbulent boundary layer developing on the solid body.
Applications
Itâ„¢s application is confined to the ships, especially large ships. Ships such as tankers play a major role in marine transportation.
Conclusion
The near-wall concentration of the bubbles is an important factor and when this drops to a low level the drag reduction effect is diminished or eliminated. This indicates that the interactions of the bubbles with the near-wall turbulence are critical.
Smaller bubbles in general are more effective in reducing drag.
At higher Reynolds numbers the range of bubbles sizes may be effective in reducing drag.