Which is faster, a 3 or 4 blade prop?
With fewer blades, a three-blade prop creates less drag, delivering higher speeds, improved fuel mileage, and that perfect hole shot for your high-speed boat. As you mentioned, your trade off is at the higher end of the speed and RPM scale where a 3 blade prop will out perform a 4 blade prop. You can expect to loose about 5% off the top speed with a 4 blade prop.
What are the two types of propellers?
Fixed-pitch and ground-adjustable propellers are designed for best efficiency at one rotation and forward speed. In other words, they are designed to fit a given aircraft and engine combination. A propeller may be used that provides the maximum propeller efficiency for takeoff, climb, cruising, or high speeds. Propeller blades should have an airfoil shape, with the cross-section showing camber and twist, which will generate more lift than flat blades of the same area. A flat blade is not as efficient as a fully shaped blade, with camber, curve and twist.Another leading theory states that single-blade propellers are more efficient because they don’t experience the wake turbulence of other blades, and thus rotate through less disturbed air.
What is a plane propeller called?
A propeller (often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propeller rpm refers to the rotational speed of a propeller, typically measured in revolutions per minute, which influences the effectiveness and efficiency of propeller designs, such as increased diameter or low rpm configurations.