Propellers Flashcards
With increasing TAS, the angle of attack of the propeller will ___
reduce
The propeller pitch angle is the angle between ___ and ___
The plane of rotation and the blade cord line
At 0 TAS, the propeller angle of attack is the angle between the ___ ___ and the ___ __ ___
chord line, plane of rotation
With a TAS >1, the angle between the resultant airflow and the plane of rotation is called the ___ ___
helical path, or the angle of advance
The thrust bending force tries to ___ the blades ___
bend, forward
Torque bending force tires to bend the blade in the ___ direction to/as its rotation
opposite
Increasing the blade camber will ___ the power absorption capability
improve
Geometric pitch is ___
how far the propeller should move forward in one rotation when the helix angle is equal to the blade angle
The helix angle will be equal to the blade angle when the angle of attack is ___
zero
The effective pitch is ___
how far the propeller actually moves in one revolution
The difference between the effective pitch and the geometric pitch is called the ___
propeller slip
The blade angle of attack, when the TAS is greater than 0, is the angle between the ___ and the ___
section chordline and relative airflow
The advance ratio is ___
A non-dimensional measure of the forward speed in relation to the speed of the tip of the propeller blade
The advance ratio formula is ___
Forward Speed / ( Propeller rotational speed x Diameter )
Propeller resisting force is the same as ___ force on a conventional airfoil
Drag
The aerodynamic turning moment will try to twist the blades to a ___ pitch
coarse
Centrifugal turning moment will try to twist the blades to a ___ pitch
fine
What is meant by “absorbing power”?
The resisting force must be able to balance engine torque to ensure RPM isn’t too high
Increasing chord ___ CTM
increases
Torque produces ___, whilst slipstream produces ___
roll, yaw
When the RPM lever is moved backwards, the blade pitch becomes more ___ and the rate of descent will ___
coarse, decrease
Blade angle of attack is determined by the added vectors of ___ and ___
propeller RPM and TAS
Increasing speed at constant RPM will ___ the blade angle of attack
decrease
Increasing RPM at constant TAS will ___ the blade angle of attack
increase
At constant Mach, the thrust and fuel flow decrease with ___ pressure at constant temperature
decreasing
