18ME15/25
Model Question Paper- CBCS scheme
USN
Seventh Semester B.E. Degree Examination, Dec- 2018 Jan 2019
Tribology
Time: 3hrs. Max. Marks: 80
Note: 1.Answer any FIVE full questions, choosing one full question from each module.
2. Use of Tribology handbook is permitted
MODULE I
1
a. Distinguish between Dynamic and Kinematic viscosity Fluidity and viscosity Newtonian and Non Newtonian fluid
b. Explain with neat sketch construction and working of Saybolt and Ostwald viscometers.
(08 Marks)
(08 Marks)
OR
2
a. Define the following
Tribology Lubrication Viscosity Newtonian fluid
b. Explain with neat sketch construction and working of Saybolt and falling sphere viscometers.
(08 Marks)
(08 Marks)
MODULE II
3
a. Define wear and explain type of wear with sketches
b. Explain in brief friction measuring methods.
(08 Marks)
(08 Marks)
OR
4
a. Define friction. State laws for friction.
b. Explain with neat sketch abrasive wear tester.
(08 Marks)
(08 Marks)
MODULE III
5
Derive petroff's equation. State the assumptions made.
(16 Marks)
OR
6
Stating the assumptions made in deriving Reynolds, derive the Reynolds equation in two dimensions.
(16 Marks)
MODULE IV
7
a. Derive an expression for oil flow rate in a hydrostatic bearing.
b. A pivoted shoe of a slider bearing has square shape. The load acting on the bearing is 13.34kN, velocity of the moving member is 5.08m/s. lubricating oil is SAE 40. The expected mean temperature of oil film is 900 C. permissible minimum oil film thickness is 1.905*10-5m. Find
i)Required dimensions of the shoe
ii)Coefficient of friction in the bearing under given operating condition
iii)Power loss
Assume that inclination of surface corresponds to maximum load carrying capacity. Neglect effect of end flow of oil
(08 Marks)
(08 Marks)
OR
15ME751
Important Note: 1. On completing your answers, compulsorily draw diagonal cross lines on the remaining blank pages.
2. Any revealing of identification, appeal to evaluator and /or equations written e.g, 38+2 40, will be treated as malpractice.
8
a. Derive the expression for rate of flow of oil and load carrying capacity for on hydrostatic step bearing.
b. The following data refers to the hydrostatic thrust bearing.
W 460KN, outside dia 400mm, pocket dia 250mm, oil film thickness 0.15m, speed 2800rpm, viscosity 0.033 pa-s. Determine Inlet pressure, Energy lost in pumping, Power loss due to friction, Total energy lost, and Coefficient of friction.
(08 Marks)
(08 Marks)
MODULE V
9
a. Discuss any six desirable properties of bearing materials.
b. Explain the properties and applications of commonly used bearing materials.
(08 Marks)
(08 Marks)
OR
10
a. Explain Electroless and Electro plating wit neat sketches.
b. Define Surface Engineering. Explain Ion Implantation method.
(08 Marks)
(08 Marks)