[L3]_AERODYNAMICS OF TURBINE BLADES

Question 1

ENGY-688

In the context of Aerodynamics, what is meant by the term ‘Aero’?

[L3]

Answer 1

The Interaction of Air Movement

[L3]

Question 2

ENGY-688

What is the combined definition of Aerodynamics?

[L3]

Answer 2

The study of motion for air and fluids on a body

[L3]

Question 3

ENGY-688

What is the cross section length of an airfoil?

[L3]

Answer 3

Chord

[L3]

Question 4

ENGY-688

What shape is a positive Camber?

[L3]

Answer 4

Convex

[L3]

Question 5

ENGY-688

What percentage of the chord length is the maximum thickness?

[L3]

Answer 5

30%

[L3]

Question 6

ENGY-688

Where is the center of gravity of an airfoil located?

[L3]

Answer 6

Mean Camber Line

[L3]

Question 7

ENGY-688

What is the most forward point of the mean camber line?

[L3]

Answer 7

The Leading Edge

[L3]

Question 8

ENGY-688

What is the most rearward point of the mean camber line?

[L3]

Answer 8

The Trailing Edge

[L3]

Question 9

ENGY-688

What does NACA stand for?

[L3]

Answer 9

National Advisory Committee for Aeronautics

[L3]

Question 10

ENGY-688

What is a characteristic of the first two digits being zero in an airfoil?

[L3]

Answer 10

Symmetrical Airfoil

[L3]

Question 11

ENGY-688

What is the Coanda Effect?

[L3]

Answer 11

Fluid jet stream attachment

[L3]

Question 12

ENGY-688

What type of airfoils do wind turbine blades use?

[L3]

Answer 12

Non-Symmetrical (cambered)

[L3]

Question 13

ENGY-688

Do air molecules meet at the trailing edge of blade?

[L3]

Answer 13

No

[L3]

Question 14

ENGY-688

What happens to the speed of air on the upper camber?

[L3]

Answer 14

Increases

[L3]

Question 15

ENGY-688

What happens to pressure as the velocity of air increases?

[L3]

Answer 15

Pressure Decreases

[L3]

Question 16

ENGY-688

Define aerodynamic force (F) direction as it relates to an airfoil

[L3]

Answer 16

Perpendicular to the Airfoil

[L3]

Question 17

ENGY-688

How do you calculate aerodynamic force?

[L3]

Answer 17

F = Pnet * A

[L3]

Question 18

ENGY-688

How is drag force oriented in relation to the wind?

[L3]

Answer 18

Parallel to wind direction

[L3]

Question 19

ENGY-688

What does α (alpha) represent?

[L3]

Answer 19

Angle of Attack

[L3]

Question 20

ENGY-688

In the equations, what does the symbol δ represent?

[L3]

Answer 20

Air Density

[L3]

Question 21

ENGY-688

What aerodynamic forces can act on an airfoil?

[L3]

Answer 21

Lift and Drag

[L3]

Question 22

ENGY-688

Under what condition does Lift become reversed?

[L3]

Answer 22

Negative Angle of Attack

[L3]

Question 23

ENGY-688

What happens when the critical angle of attack is surpassed?

[L3]

Answer 23

Stall

[L3]

Question 24

ENGY-688

What does ωblade represent?

[L3]

Answer 24

Rotational speed of the blade

[L3]

Question 25

ENGY-688

What happens to angle of attack (α) when pitch angle (β) is increased?

[L3]

Answer 25

α is reduced

[L3]

Question 26

ENGY-688

What does TSR stand for?

[L3]

Answer 26

Turbine Blade Tip Speed Ratio

[L3]

Question 27

ENGY-688

What is the relationship between number of blades and TSR?

[L3]

Answer 27

Fewer blades, higher TSR

[L3]

Question 28

ENGY-688

What is the tip velocity?

[L3]

Answer 28

Maximum speed of rotor tip

[L3]

Question 29

ENGY-688

What issues arise from a high TSR?

[L3]

Answer 29

Turbulent air and failures

[L3]

Question 30

ENGY-688

What is the consequence of elevated TSR on a structure?

[L3]

Answer 30

Structural Failure

[L3]