MECHANICAL ENGINEERING
ME-302 Dynamics of Machines
Time 3 Hours Maximum Marks 70
Note:
Attempt any Five questions. All questions carry equal marks
Q.1
Explain the
dynamic force analysis including inertia and frictional forces of planer mechanisms.
Q.2
Derive the
expression for forces on the reciprocating parts of an engine, neglecting
The weight
of the connecting rod.
Q.3
The
following data refer to two cylinder
Locomotives
with cranks at 90 degree Reciprocating mass
per cylinder 300 kg. Crank radius 0.3 m; Driving wheel diameter 1.8 m; Distance
between cylinder centre lines 0.65 m; Distance between the driving wheel central
planes 1.55 m. Determine
(l) the fraction
of the reciprocating masses to be
balanced, if
the hammer blow is not to exceed
45 kN at
96.5 kmph;
(2) the
variation intractive efforts; and (3) the maximum swaying couple.
Q.4
A shaft
carries four masses A, B, C and D of magnitude 200 kg., 300 kg., 400 kg. and
200
kg.
respectively and revoling at radii 80 mm,
70 mm, 60 mm
and 80 mm in planes measured
from A at
300 mm, 400 mm and 700 mm. The
angles
between the cranks measured anticlokwise are A to B 450, B to C 700 and C to D
1200. The balancing masses are to be placed in planes X and The distance
between the planes A and X is. 100 mm, between x and Y is 400 mm and between Y
and D is 200mm. If the balancing masses revolved at a radius of 100 mm, find
their magnitude and angular positions.
Q.5
In an engine governor of the Porter type, the upper
and lower arms are 200 mm and 250mm respectively and pivoted on the axis of rotation.
The mass of the central load is 15kg., the mass of each ball is 2 kg. and
friction of the sleeve together with the resistance of the operating gear is
equal to a load of 25 N at the sleeve. If the limiting inclinations of the upper
arms to the vertical and 300 and 400,find, taking friction into account, range
of speed of the governor.
Q.6
What is the
difference between absorption and
transmissioin
dynamometers? Describe with sketches one form of torsion dynamometer explain
with detail the calculations involved in finding the power transmitted.
Q.7
The
turbine rotor of a ship has a mass of 3500kg. It has a radius of gyration of
0.45 m and a speed of 3000 rpm clockwise when looking from stem. Determine the
gyroscopic couple and its effect upon the ship
(1)When the
ship is steering to the left on
a curve of
100 m radius at a speed of 36km/h.
(2)When the
ship is pitching a simple harmonic motion, the bow falling with its maximum
velocity. The period of pitching is 40 seconds and the total angular
displacement between the two extreme positions of pitching is 12degrees.
Q.8 Explain
the following
(a)
Gyroscopic Stabilization
(b)
Hydraulic Dynamometer
(c) Hunting
of Centrifugal Governors.
