Helicopter Engineering
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R07
Code No: 07A82104
Set No. 2
IV B.Tech II Semester Examinations,AUGUST 2011
HELICOPTER ENGINEERING
Aeronautical Engineering
Time: 3 hours
Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
1. (a) Describe with sketches and plots the difference between a conventional airplane and Helicopter. Emphasize on the generation of lift in both cases.
(b) Explain with sketches and plots the requirement of tail rotor in a conventional single rotor helicopter. Describe the rotor transmission mechanism.
[8+8]
D
L
2. (a) Discuss the aerodynamics of an airplane propeller and a ducted fan/rotor used for forward motion of a Hovercraft.
R
O
(b) Provide the principal details of a Hovercraft in as far as its forward and hovering motion is concerned.
[8+8]
3. A helicopter weighs 30,000N and has a single rotor of 16m diameter. Using momentum theory estimate the power required for level flight at a speed of 20m/sec at sea level. Take CD = 0.0065 based on rotor disc area.
[16]
W
U
4. A rotor in a given flight condition has the following flapping motion with respect to the control axis (control plane): β (ψ ) = 60 − 40 cos ψ − 40 sin ψ .
T
N
(a) Sketch a side view and rear view of the rotor.
(b) How much is the TPP inclined in the fore and aft direction? Forward or backward? J
(c) How much is the TPP inclined laterally? Is the advancing or retreating blade high? (d) What angle does the blade make with the control plane at Φ = 00 , 900 ,1800 ,
2700 ,
(e) At what azimuth angle is the flapping angle greatest?
(f) What is the flapping angle at this point?
[16]
5. A helicopter is operating in level forward flight at 63.6ms−1 under the following conditions: shaft power supplied = 488.4kw, w = 2722 Kg, ρ = 1.038 Kg/m3 . The rotor parameters are R = 5.75m. σ = 0.08, ΩR=212.12ms−1 , K = 1.15, Cdo = 0.01.
(a) How much power is required to overcome induced losses?
(b) How much power is
R07
Code No: 07A82104
Set No. 2
IV B.Tech II Semester Examinations,AUGUST 2011
HELICOPTER ENGINEERING
Aeronautical Engineering
Time: 3 hours
Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
1. (a) Describe with sketches and plots the difference between a conventional airplane and Helicopter. Emphasize on the generation of lift in both cases.
(b) Explain with sketches and plots the requirement of tail rotor in a conventional single rotor helicopter. Describe the rotor transmission mechanism.
[8+8]
D
L
2. (a) Discuss the aerodynamics of an airplane propeller and a ducted fan/rotor used for forward motion of a Hovercraft.
R
O
(b) Provide the principal details of a Hovercraft in as far as its forward and hovering motion is concerned.
[8+8]
3. A helicopter weighs 30,000N and has a single rotor of 16m diameter. Using momentum theory estimate the power required for level flight at a speed of 20m/sec at sea level. Take CD = 0.0065 based on rotor disc area.
[16]
W
U
4. A rotor in a given flight condition has the following flapping motion with respect to the control axis (control plane): β (ψ ) = 60 − 40 cos ψ − 40 sin ψ .
T
N
(a) Sketch a side view and rear view of the rotor.
(b) How much is the TPP inclined in the fore and aft direction? Forward or backward? J
(c) How much is the TPP inclined laterally? Is the advancing or retreating blade high? (d) What angle does the blade make with the control plane at Φ = 00 , 900 ,1800 ,
2700 ,
(e) At what azimuth angle is the flapping angle greatest?
(f) What is the flapping angle at this point?
[16]
5. A helicopter is operating in level forward flight at 63.6ms−1 under the following conditions: shaft power supplied = 488.4kw, w = 2722 Kg, ρ = 1.038 Kg/m3 . The rotor parameters are R = 5.75m. σ = 0.08, ΩR=212.12ms−1 , K = 1.15, Cdo = 0.01.
(a) How much power is required to overcome induced losses?
(b) How much power is