Third year, Department of Mechanical Engineering
First
and second Units Questions.
Answer ALL Questions
PART A – (10 x 2 = 20 Marks)
2. State D’alemberts principle
3. Define crank effort and crank pin
effort
4. What are the conditions for state
equilibrium
5. Specify the difference between
static force and dynamic force analysis
6. What are the requirements of an
equivalent dynamical system
7. Define mass moment of inertia
8. Define compound pendulum
9. Give expression for equivalent
length of compound pendulum
10. What is
engine shaking force
PART - B (5 x 16=80
Marks)
Answer all questions
1) A shaft fixed on Flywheel
Rotates at 520 rpm drives a machine. The torque of the machine of various in a cycle manner over the period of 3 rotation. The torque rises from 750N-m to
3000N-m uniformly during half rotation and
remaining constant for the following rotation. then fall uniformly 750N-m.during
next half rotation and remains constant at one rotation. the cycle be defected their
after. Determine The power required to drive the machine and percentage
Fluctuation It Speed. If The driving torque obtain to shaft is constant and mass
of flywkeel 500kg with radius of gyration is 600mm
2) A horizontal steam engine running
at 120 rpm as bore of stroke of 400mm.The connecting rod Is 0.6m and mass of reciprocating
part is 60kg,When the crank has turn through an Angle of 450 from the
Inner dead centre The Pressure of cover end side is 550kN/m2.Considering
The Diameter of The Piston rod is 50mm.turning Moment of crank Shaft Thrust on
The Power of The Bearing. Accleration of the Flywheel. If The Power of the engine Is
20kw.mass of The Flywheel 60kg and radius of gyration 0.6m
3) A horizontal steam engine running
at 210 rpm Has a bore 190mm And Stroke of 350mm.Piston rod is 20mm In diameter
And connecting rod Length 950mm.The Mass of reciprocating part is 8kg And The firictional
resistence Is Equivalent To Force of 350N.Determine The following ,When The
Crank is at 115°From Inner Dead Centre The Mean Pressure Being 4500N/m2
An The Core Side And 100N/m2 on The Crank Side I)Thrust on The
Connecting Rod Ii)Thrust on The Cylinder Rod Iii)Load on The Bearing Iv)Turning
Moment on Crank Shaft
4) A Single Cylinder Vertical
Engine Has A Bore of 300mm And A Stroke of 400mm .A Connecting Rod Is 1000mm
Long . The Mass of Reciprocating Part Is 140kg of The Expansion Stroke With The
Crank At 30° From Top Dead Centre. the Gas Pressure Is 0.7mpa.If The Engine
Runs At 250rpm.Determine I)Net Force Acting on The Piston Ii)Resultant Wall
Load on gudgeon Iii)Thrust on A Cylinder
5) A Rotating Shaft Carries
Four Unbalanced Mass 18kg,14kg,16kg,12kg At Radii 5cm,6cm,7cm,6cm The Second
And Third And Fourth Masses Rotating Plains 8cm,16cm,28cm Measured From The
Plane of The First Mass And Are Angular Locate At 60°,135° And 270° Measured
Clockwise From First Mass Looking From The Mass end of The Shaft. The Shaft
Dynamical Balanced By Two Masses Both Locate At 5cm Radii And Revolving In
Planes Midway Between Those Are First And Second Masses And Midway Between
Those of Third And Fourth Masses. Determine Graphically Are otherwise the Magnitude
of Masses And Their Respective Angular Position
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