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.