Aerodynamics Flashcards
The Forces Acting on the Aircraft
1.
2.
3.
4.
- Thrust
- Drag
- Lift
- Weight
Thrust is the forward force produced by the powerplant/propeller or rotor. It overcomes the force of ________.
Drag
True/False
As a general rule, thrust acts parallel to the longitudinal axis.
True
Drag is a rearward force, retarding force caused by disruption of airflow by the wing, rotor, fuselage, and outer protruding objects. Drag opposes _______, and acts rearward parallel to the relative wind.
Thrust
Weight is the combined load of the aircraft itself, the crew, the fuel, and the cargo or baggage. Weight pulls the aircraft downward because of the force of gravity. It opposes ________, and acts vertically downward through the plane’s center of gravity (CG).
Lift
True/False
In regards to the four forces acting upon an airplane:
In steady flight, the sum of these forces is always zero.
True
Word selection:
Drag is in the force that (assists or resists) movement of an aircraft through the air.
Resists
There are two basic types of drag:
- _________
- _________
1. Parasite Drag
2. Induced Drag
Parasitic drag is any drag not associated with the production of _______.
Lift
There are three forms of parasite drag:
1.
2.
3.
1. Form Drag
2. Interference Drag
3. Skin friction
Form drag is the porition of parasite drag generated by the aircraft due to its shape and airflow around it. Name some aircraft components that this would include:
Engine cowlings, antennas, and the aerodynamic shapes of other components
Interference drag comes from the intersection of _______ that creates eddy currents, turbulence, or restricts smooth airflow.
airstreams
An example of a location where interference drag would occur on an airplane…
The intersection of the wing and the fuselage at the wing root. This location has significant interference drag.
Air flowing around the fuselage collides with air flowing over the wing, merging into a current of air different fromt he two original currents. Fairings are often used to reduce this tendency.
Skin friction drag is the aerodynamic force due to the contact of moving air with the _________ of an aircraft.
Surface/skin
Every surface no matter its appearance has a rough ragged surface when viewed under a microscope. Air molecules come into contact with the surface of the wing and become virtually motionless.
Induced drag is the second basic type of drag. I
