AAE 334 MIDTERM 1 EXAM QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026
What's the difference between the graph of a cambered airfoil and symmetric airfoil? - Answers
Symmetric passes through origin
Cambered passes through around -10 degrees
Center of Pressure - Answers The balance point of aerodynamic forces, average location of pressure,
with no pitching moment
Aerodynamic Center - Answers Location on airfoil where the aerodynamic moment is constant
According to thin airfoil theory, where is the aerodynamic center located on an airfoil? - Answers
Quarter chord length, c/4
How can shear stress be used to locate the point of flow separation? - Answers By monitoring the
velocity gradient (shear stress), and noting where is becomes close to zero
Kutta Condition - Answers Flow leaves the upper and lower surfaces of the trailing edge smoothly.
If angle made by upper and lower surface is non-zero, then the trailing edge is a stagnation point.
What's the difference between flow before and after stall? - Answers Before Stall: Flow is smooth,
attached, and generates efficient lift.
After Stall: Flow separates, becomes turbulent, lift decreases sharply, and drag increases.
Airfoil Thickness - Answers Stall: Thicker airfoils begin to stall earlier, but have a more gradual stall,
maintaining a high lift coefficient for a large span of angles of attack. Thinner airfoils have higher
peaks in lift coefficients, but drop off sooner.
Skin Friction: Thicker airfoils cause more skin friction due to larger surface area.
For viscous flow over a low-speed airfoil, boundary layer separation can happen: - Answers In an
adverse pressure gradient
For viscous flow over a low-speed airfoil, boundary layer transition can happen: - Answers In either a
favorable or an adverse pressure gradient depending on the development of the boundary layer
For viscous flow over a low-speed airfoil, as the Reynolds number is increased, the location of
boundary layer transition from laminar to turbulent flow - Answers Moves towards the leading edge
For viscous flow over a low-speed 2-D airfoil, boundary layer separation happens at a point where: -
Answers The skin friction coefficient changes from positive to negative
The lift curve slope, 𝑑𝑐ℓ⁄𝑑α, for a thin airfoil at low-speed when the angle of attack is measured in
radians is approximately - Answers 2π
A typical value for the maximum lift coefficient of a single element airfoil is: - Answers 1.5
Does the transition from laminar to turbulent flow increase or decrease the drag on a thin cambered
airfoil at a small angle of attack? - Answers Increase. The flow is fully attached, and the drag is mostly
due to viscous friction, which is increased by transition
Does the transition from laminar to turbulent flow increase or decrease the drag on a sphere? -
Answers Decrease. The drag is mostly due to pressure drag due to flow separation. Since transition
delays separation and increases the pressure in the separated region, drag will decrease
Airfoil naming convention - Answers First digit represents the maximum camber compared to chord
length.
Second digit represents location of maximum camber.
Last two digits refer to the maximum thickness of the airfoil as a percentage of the chord.
4412: Would be 4% camber, maxing at 40% of chord length, with 12% thickness.
0021: Would be a symmetric airfoil with 21% thickness.
On a Cp distribution graph, what does a negative slope indicate? - Answers An adverse pressure
gradient
What does the first negative peak on a Cp distribution graph indicate? - Answers Front Stagnation
Point
On a shear stress distribution graph, which surface is represented by the top line? - Answers Upper
Surface
On a shear stress distribution graph, how can you find the laminar separation on the upper surface?
How can you find the reattachment point on the lower surface? - Answers The first time the upper
surface hits zero, then the first time the lower surface hits zero
Looking at a Cl/Cd graph, how can you determine the location of maximum lift to drag ratio? -
Answers Draw a positive tangent line from the origin, mark intersection
What's the difference between the graph of a cambered airfoil and symmetric airfoil? - Answers
Symmetric passes through origin
Cambered passes through around -10 degrees
Center of Pressure - Answers The balance point of aerodynamic forces, average location of pressure,
with no pitching moment
Aerodynamic Center - Answers Location on airfoil where the aerodynamic moment is constant
According to thin airfoil theory, where is the aerodynamic center located on an airfoil? - Answers
Quarter chord length, c/4
How can shear stress be used to locate the point of flow separation? - Answers By monitoring the
velocity gradient (shear stress), and noting where is becomes close to zero
Kutta Condition - Answers Flow leaves the upper and lower surfaces of the trailing edge smoothly.
If angle made by upper and lower surface is non-zero, then the trailing edge is a stagnation point.
What's the difference between flow before and after stall? - Answers Before Stall: Flow is smooth,
attached, and generates efficient lift.
After Stall: Flow separates, becomes turbulent, lift decreases sharply, and drag increases.
Airfoil Thickness - Answers Stall: Thicker airfoils begin to stall earlier, but have a more gradual stall,
maintaining a high lift coefficient for a large span of angles of attack. Thinner airfoils have higher
peaks in lift coefficients, but drop off sooner.
Skin Friction: Thicker airfoils cause more skin friction due to larger surface area.
For viscous flow over a low-speed airfoil, boundary layer separation can happen: - Answers In an
adverse pressure gradient
For viscous flow over a low-speed airfoil, boundary layer transition can happen: - Answers In either a
favorable or an adverse pressure gradient depending on the development of the boundary layer
For viscous flow over a low-speed airfoil, as the Reynolds number is increased, the location of
boundary layer transition from laminar to turbulent flow - Answers Moves towards the leading edge
For viscous flow over a low-speed 2-D airfoil, boundary layer separation happens at a point where: -
Answers The skin friction coefficient changes from positive to negative
The lift curve slope, 𝑑𝑐ℓ⁄𝑑α, for a thin airfoil at low-speed when the angle of attack is measured in
radians is approximately - Answers 2π
A typical value for the maximum lift coefficient of a single element airfoil is: - Answers 1.5
Does the transition from laminar to turbulent flow increase or decrease the drag on a thin cambered
airfoil at a small angle of attack? - Answers Increase. The flow is fully attached, and the drag is mostly
due to viscous friction, which is increased by transition
Does the transition from laminar to turbulent flow increase or decrease the drag on a sphere? -
Answers Decrease. The drag is mostly due to pressure drag due to flow separation. Since transition
delays separation and increases the pressure in the separated region, drag will decrease
Airfoil naming convention - Answers First digit represents the maximum camber compared to chord
length.
Second digit represents location of maximum camber.
Last two digits refer to the maximum thickness of the airfoil as a percentage of the chord.
4412: Would be 4% camber, maxing at 40% of chord length, with 12% thickness.
0021: Would be a symmetric airfoil with 21% thickness.
On a Cp distribution graph, what does a negative slope indicate? - Answers An adverse pressure
gradient
What does the first negative peak on a Cp distribution graph indicate? - Answers Front Stagnation
Point
On a shear stress distribution graph, which surface is represented by the top line? - Answers Upper
Surface
On a shear stress distribution graph, how can you find the laminar separation on the upper surface?
How can you find the reattachment point on the lower surface? - Answers The first time the upper
surface hits zero, then the first time the lower surface hits zero
Looking at a Cl/Cd graph, how can you determine the location of maximum lift to drag ratio? -
Answers Draw a positive tangent line from the origin, mark intersection
