11-06-2013, 04:53 PM
SEMESTER EXAMINATIONS FOR AEROSPACE SENSORS AND MEASUREMENT SYSTEMS
AEROSPACE SENSORS.pdf (Size: 38.79 KB / Downloads: 14)
Answer any five questions
All questions carry equal marks
1.a) Define the terms sensitivity and calibration of an instrument with an example.
b) Give different types of errors that occur during measurement with an instrument. Suggest minimizing these errors.
2.a) What is meant by positive displacement flow meter? Explain any one of the positive displacement flow meters with neat sketch.
b) Explain neatly with a sketch, the working of a Doppler Global Velocimetry (DGV).
3.a) Explain path lines, streak lines, stream lines and time lines in a fluid flow.
b) Explain the different methods used for flow field visualization.
4.a) Explain aerodynamic wind tunnels.
b) Describe the three-component Roof balances.
5.a) Explain the working principle of electrical strain gauge for strain measurement.
b) A rectangular rosette is mounted on a steel plate having E=200 GPa and Poison’s ratio = 0.3. The three strains are measured as
ε1 = + 500 μ mm/mm
ε2 = + 400 μ mm/mm
ε3 = - 100 μ mm/mm
Calculate the principal strains and stresses, the maximum shear stress, and the orientation angle for the principal axis of the stress.
6.a) Describe basic concept of seismic instrument.
b) A cantilever beam of span 3 m of steel of cross sectional area 10 mm x 20 mm is subjected to a free end transverse load of 4 kN, along the depth. Determine the natural frequency of vibration. If the beam used as a simply supported beam loading at center, determine the frequency and vibration.
7.a) Explain with neat sketch the working principle of pendulous accelerometer (Open and closed loop).
b) Explain the construction, principle of working and salient features of Piezo-electric type accelerometer.
8. Write short notes on
a) Rate gyros
b) Magnetometers
c) Sun sensors.