T&T: Propeller question

[John Baker]

I doubt the jury is still out.  This is a physics question and I bet the answer is known.  There are also many variables affecting this issue.  Maybe a four blade prop is more efficient on a displacement boat that chooses to cruise right up against the hullspeed....IOW, the prop is "loaded" all the time whereas a boat going significantly slower than hullspeed(or faster...planing) may not be under as much load and is more in a balance equilibrium state that the 3 or 2 bladed props are more efficient.  I am talking outta my rear here.  I do know 2 bladed props on airplanes are more efficient.....dunno why but I am sure the same fluid dynamics apply....probably has something to do with the blades operating in "clean air"(or water) as opposed to more turbulent air/water operating in the wake of the preceding blade.  I have a 5 bladed prop on my boat but it is due to physical limitations of a prop tunnel.
   
  Trawler on,
  John

       
---------------------------------
Get the free Yahoo! toolbar and rest assured with the added security of spyware protection.