PTU Punjab Technical University B-Tech May 2019 Question Papers 6th Semester Aerospace Engineering?
Roll No.
Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(ANE) (Sem.?6)
HELICOPTER ENGINEERING
Subject Code : ANE-324
M.Code : 60533
Time : 3 Hrs. Max. Marks : 60
INSTRUCTION TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.
SECTION-A
Q1 Explain the following terms :
(a) Teetering type rotor
(b) Articulated rotor
(c) Autorotation
(d) NOTAR.
(e) Synchropter
(f) Dissymmetry of lift
(g) Solidity
(h) Precession.
(i) Hinge-less rotor
(j) Feathering motion
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SECTION-B
Q.2 Explain the salient features of an articulated main rotor with the help of neat labelled
sketch.
Q.3 A helicopter having mass of 10000N has a rotor diameter of 10 m. The rotor rotates at
100 rpm and is hovering at sea level conditions. Find the disk loading, induced velocity and
rotor thrust coefficient.
Q.4 Explain `actuator disk theory' using relevant expressions.
Q.5 A tilt rotor helicopter weighs 80000N. The rotor diameter is 12m. On the basis of
momentum theory, estimate the power required for the rotorcraft to hover at sea level on
standard day. Assume that the figure of merit is 0.7 and transmission losses amount to 5%.
Q.6 Explain the `vortex ring state' with the help of a neat sketch.
SECTION-C
Q.7 Explain the importance of vibration absorbers in helicopters. Distinguish between active
and passive vibration absorbers. Explain active vibration control systems with the help of
sketches.
(2,3,5)
Q.8 Explain the effect of following on helicopter performance :
(2,3,2,3)
(a) Number of blades
(b) Ground effects
(c) Induced velocity
(d) Induced power
Q.9 Write notes on the following :
(2?5)
(a) Stability characteristics and their importance
(b) Auto-stabilization
NOTE : Disclosure of identity by writing mobile number or making passing request on any
page of Answer sheet will lead to UMC case against the Student.
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This post was last modified on 04 November 2019