Folding propeller
Encyclopedia
A folding propeller is a type of propeller
where the propeller blades fold in when the propeller is not in use, and out when the propeller is in use. This type of propeller is often used on sailing yachts to reduce drag
while under sail. It is also used on microfilm model aircraft. Pros and cons of folding compared with fixed propellers are:
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...
where the propeller blades fold in when the propeller is not in use, and out when the propeller is in use. This type of propeller is often used on sailing yachts to reduce drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
while under sail. It is also used on microfilm model aircraft. Pros and cons of folding compared with fixed propellers are:
| Pros | Cons |
|---|---|
| Folding propellers reduce drag while not in use. Less fluid resistance allows for more speed through the water or air. | Non self feathering folding propellers have poor performance when used in reverse. |
| Less noise and vibration than fixed blades when not in use since the propeller will not rotate when forced through water. | They cost more than fixed propellers. |
| Self feathering propellers may increase efficiency because the blades are always pitched at the optimal angle. | For marine propellers, vegetation growth can stop the propeller from folding in/out. |