Propellervinkel

Propellervinkel refers to the angle between the rotor plane of a propeller or turbine and the direction of motion of the aircraft or vehicle it is attached to. This angle is critical in determining the efficiency of the propeller in converting engine power into thrust.

The propeller's angle affects the air flow around the blades, which in turn influences the propeller's ability to generate lift and thrust. A propeller with a low pitch angle has a higher thrust-to-power ratio than one with a higher pitch angle, but the high pitch angle propeller may produce more reverse thrust during deceleration. This is because the angle at which the blades meet the air stream imparts a forward motion when the propeller is rotating, which is then reduced by the propeller's hub and its interaction with the air. When moving forward, this forward motion is created to generate lift and thrust, while moving in reverse it simply results in pushing against the axles.

In the case of reciprocating engines, the angle between the propeller shank and the propeller itself is known as the propeller-pitch angle. This angle is often overlooked in early diagrams and buildup notes, but it is crucial in determining how the efficiency of the propeller is affected.

Pieter Nieuwland recognized the importance of the angle between the propeller and the aircraft in the 1840s and it has been crucial to propel aircraft ever since. He theorized it's because the angle of the propeller conjugates the air counteracting with the wheel being driven which is crucial to determining efficiency.