ME55 – APPLIED HYDRAULICS AND PNEUMATICS MODEL EXAMINATIONS

B.E./B.TECH.DEGREE MODEL EXAMINATIONS, OCT/NOV – 2011

REGULATION 2008

FIFTH SEMESTER

ME55 – APPLIED HYDRAULICS AND PNEUMATICS

MECHANICAL ENGINEERING

Time: Three Hours                                Date: 14.10.2011                               Maximum: 100 marks

ANSWER ALL QUESTIONS

PART – A (10 x 2 = 20 marks)

1.      Define Fluid power.

2.      Compare hydraulic and pneumatic system?

3.       Name any four desirable characteristics of hydraulic pumps?

4.      Why end cushions are used in cylinders?

5.       List any four types of pressure control valves.

6.       Write the function of solenoid valve.

7.       What is the need of lubricator unit in the pneumatic system?

8.       What are the reasons for pressure drop in pneumatic lines?

9.       Define FLUIDICS?

10.   Define coanda effect.

PART – B (5 x 16 = 80 marks)

11.  (a) (i) Discuss the factors to be considered in the selection of hydraulic fluids. (12)
     (ii) Discuss the properties of hydraulic fluids.                                                             (4)
                                                             (OR)
(b) (i) What is the basic consideration in the design of a hydraulic circuit. (8)
     (ii) Define Reynolds Number?                                                                                     (2)
     (iii) Differentiate between laminar and turbulent flow.                                              (6)

12.  (a) (i) Explain the working principle of Unbalanced vane pump and determine its                             performance Measures.                                                                                                   (10)

           (ii) Explain with a diagram the working of a cylinder.                                           (6)

(OR)

(b) (i) Explain the working principle of external gear pump and determine its performance

Measures.                                                                                                                         (10)

(ii) Explain the factors which affect the selection of pumps and discuss in detail the          classification and performance features of different types of hydraulic pumps             (6)

13.  (a) (i) Explain the construction and working of pressure regulated flow control valve with neat diagram.                                                                                                                             (8)

    (ii) Make a circuit sketch, showing the use of an accumulator, as a secondary power source.                                                                                                                               (8)

(OR)

(b) (i) Explain the working principle of pressure intensifier, with neat diagram.       (8)                                                                                                         

    (ii) Explain the working principle of Electrical control solenoid DCV with neat diagram.                                                                                                                             (8)

14. (a) What is the synchronizing? Explain the synchronizing circuit with suitable Circuit diagram and approaches?                                                                                                (16)

(OR)

(b) (i) Draw a neat sketch of an electro-hydraulic for sequencing drilling and clamping

cylinders.                                                                                                                           (8)

    (ii) Explain the working and operation of Air over oil circuit with neat diagram.       (8) 

15.  (a) (i) Explain the construction and working principle of Electro hydraulic servo system  with neat diagram.                                                                                                             (8)

     (ii) Enunciate various criteria for the selection of pneumatic components.                 (8)

(OR)

(b) (i) List out various operating problems associated with hydraulic circuits and pump and the Corresponding possible causes and suitable remedy for each problem.              (8)

      (ii) Explain the working principle of a PLC with neat block diagram.                       (8)