Avit 323 Exam 2 UPDATED Exam Questions
and CORRECT Answers
In one sentence, define induce drag and be very specific. - CORRECT ANSWER - The aft
acting component of lift
Explain sphere of influence. - CORRECT ANSWER - Airflow influenced by the wing
itself
What happens to induced drag as: aspect ratio goes up - CORRECT ANSWER - Di
Decreases
What happens to induced drag as: Weight goes up? - CORRECT ANSWER - Di Increases
What happens to induced drag as: speed goes up? - CORRECT ANSWER - Di decreases
What happens to induced drag as altitude goes up? - CORRECT ANSWER - Di Increases
Why are wingtip vortices included in induced drag? - CORRECT ANSWER - Because
they are a consequence of the generation of lift
Define viscosity - CORRECT ANSWER - Resistance to shear/ resistance to deformation
and flow
What happens to the boundary layer during the adverse pressure gradient? - CORRECT
ANSWER - Kinetic energy decreases, air slows to the point of reversing and once fully
reversed it separates= aerodynamically dead air= form drag
, Name type of drag that increase as the boundary layer separates aft of the center of lift. -
CORRECT ANSWER - Form drag (caused by pressure differences between forward and
aft surfaces)
What causes parasite drag? - CORRECT ANSWER - Any loss of momentum of the
airstream (power plant cooling, A/C, poor construction, etc)
Define profile drag. - CORRECT ANSWER - Combination between skin friction and form
drag. It accounts for the total drag caused by the shape and surface of an object moving through
the air
What is another name for pressure drag? - CORRECT ANSWER - Form drag (pressure
differences between aft and front surfaces of an object)
Define interference drag. - CORRECT ANSWER - Drag caused by the intersection of two
objects boundary layer creating more air displacement
When is interference drag the worst? - CORRECT ANSWER - acute angles
Is total drag constant? - CORRECT ANSWER - No
What makes the total drag move to the right? - CORRECT ANSWER - Increasing altitude
What makes the total drag curve move up? - CORRECT ANSWER - Weight,
configuration
What makes the total drag curve move down? - CORRECT ANSWER - Streamline, gear
up, antennas in, anything outside and move inside
Explain ground effect. - CORRECT ANSWER - Because of flow dissipation velocity goes
down so static pressure goes up resulting in very high pressure under wing increased upwash
and CORRECT Answers
In one sentence, define induce drag and be very specific. - CORRECT ANSWER - The aft
acting component of lift
Explain sphere of influence. - CORRECT ANSWER - Airflow influenced by the wing
itself
What happens to induced drag as: aspect ratio goes up - CORRECT ANSWER - Di
Decreases
What happens to induced drag as: Weight goes up? - CORRECT ANSWER - Di Increases
What happens to induced drag as: speed goes up? - CORRECT ANSWER - Di decreases
What happens to induced drag as altitude goes up? - CORRECT ANSWER - Di Increases
Why are wingtip vortices included in induced drag? - CORRECT ANSWER - Because
they are a consequence of the generation of lift
Define viscosity - CORRECT ANSWER - Resistance to shear/ resistance to deformation
and flow
What happens to the boundary layer during the adverse pressure gradient? - CORRECT
ANSWER - Kinetic energy decreases, air slows to the point of reversing and once fully
reversed it separates= aerodynamically dead air= form drag
, Name type of drag that increase as the boundary layer separates aft of the center of lift. -
CORRECT ANSWER - Form drag (caused by pressure differences between forward and
aft surfaces)
What causes parasite drag? - CORRECT ANSWER - Any loss of momentum of the
airstream (power plant cooling, A/C, poor construction, etc)
Define profile drag. - CORRECT ANSWER - Combination between skin friction and form
drag. It accounts for the total drag caused by the shape and surface of an object moving through
the air
What is another name for pressure drag? - CORRECT ANSWER - Form drag (pressure
differences between aft and front surfaces of an object)
Define interference drag. - CORRECT ANSWER - Drag caused by the intersection of two
objects boundary layer creating more air displacement
When is interference drag the worst? - CORRECT ANSWER - acute angles
Is total drag constant? - CORRECT ANSWER - No
What makes the total drag move to the right? - CORRECT ANSWER - Increasing altitude
What makes the total drag curve move up? - CORRECT ANSWER - Weight,
configuration
What makes the total drag curve move down? - CORRECT ANSWER - Streamline, gear
up, antennas in, anything outside and move inside
Explain ground effect. - CORRECT ANSWER - Because of flow dissipation velocity goes
down so static pressure goes up resulting in very high pressure under wing increased upwash
