Turning Moment Diagrams and Flywheel topics include: Energy fluctuation, flywheel and its energy storage, coefficient of speed and energy fluctuation, turning moment diagram for single and multi cylinder engine and also four stroke cycle combustion engine. A turning moment diagram, also known as a crank effort diagram, is a graphical representation of the relationship between the turning moment and the crank angle at various crank positions. It can be used to design a flywheel for an engine to minimize crank speed variance during each cycle.  A flywheel is a mechanical device that stores... Show more

Turning Moment Diagrams and Flywheel topics include: Energy fluctuation, flywheel and its energy storage, coefficient of speed and energy fluctuation, turning moment diagram for single and multi cylinder engine and also four stroke cycle combustion engine.

A turning moment diagram, also known as a crank effort diagram, is a graphical representation of the relationship between the turning moment and the crank angle at various crank positions. It can be used to design a flywheel for an engine to minimize crank speed variance during each cycle. 

A flywheel is a mechanical device that stores energy in the form of rotational momentum. Torque can be applied to a flywheel to cause it to spin, increasing its rotational momentum. This stored momentum can then be used to apply torque to any rotating object, most commonly machinery or motor vehicles. 
The turning moment diagram can also be used to determine the fluctuation of energy for one complete cycle of operation. 

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Machine Dynamics Practice Test: Turning Moment Diagrams and Flywheel

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25 Questions

1. Turning moment is maximum when the crank angle is 90 degrees.

TrueDon't KnowMaybeFalse

2. The coefficient of fluctuation of speed is the _____________ of maximum fluctuation of speed and the mean speed.

productratiodifferencesum

3. For a 4 stroke IC engine, the angle θ assumes a value equal to _______

ππ/22π4π

4. The coefficient of fluctuation of speed is the _________ of maximum fluctuation of speed and the mean speed.

productdifferenceratiosum

5. The curve abc in figure below is known as _________

Negative coupleInstrokeOutstrokePositive couple

6. Maximum fluctuation of energy in a flywheel is equal to

2ECSall of theseIω2CSIω(ω1 – ω2)

7. In a punching press, the requirement is to punch 40 mm diameter holes in a plate having a thickness of 15 mm. The rate at which the holes should be punched is 30 holes/min. Energy requirement is of 6 N-m per mm2 of sheared area. If the punching takes time 1/10 of a second and the speed of the flywheel varies from 160 to 140 rpm, determine the mass of the flywheel having radius of gyration of 1 m.

200 Kg327 Kg163.5 Kg654 Kg

8. The co-efficient of fluctuation of energy is the ratio of maximum energy to the minimum energy.

MaybeFalseTrueDon't Know

9. For a certain engine having an average speed of 1200 rpm, a flywheel approximated as a solid disc, is required for keeping the fluctuation of speed within 2% about the average speed. The fluctuation of kinetic energy per cycle is found to be 2 kJ. What is the least possible mass of the flywheel if its diameter is not to exceed 1 m ?

51 kg62 kg73 kg40 kg

10. Mass moment of inertia of two arbitrary masses placed will be same as the mass moment inertia of the rigid body.

FalseDon't KnowMaybeTrue

11. When mass of the reciprocating parts is neglected then the inertia force is _____

0MinimumNot definedMaximum

12. The cross-section of the flywheel arms is usually

I-sectionL-sectionrectangularelliptical

13. Energy during actual punching operation is same as the energy supplied by the motor.

FalseMaybeTrueDon't Know

14. Torque due to weight of the connecting rod affects the torque due to connecting rod.

MaybeFalseDon't KnowTrue

15. In order to reduce the heavy weight of the flywheel which of the following mechanical component is used?

EngineShaftGearsBearings

16. For a multicylinder engine, the moment of inertia of a flywheel is 6500 kg-m², from the turning moment diagram, it is found that fluctuation of energy is 56000 N-m, if mean speed is 120 rpm, then find maximum speed.

119122121118

17. From the data given:
54tr xc
Connecting rod of mass 2 kg and the distance between the centre of crank and centre of gudgeon pin is 25 cm. The Center of Gravity lies at a point 10 cm from the gudgeon pin along the line of centres.
The radius of gyration of this system about an axis through the Center of Gravity perpendicular to the plane of rotation is 11 cm.
Find the mass placed at distance l2 from center of gravity.

0.81.11.20.9

18. If the stroke punch is 100mm, find the radius of the crank in mm.

10050400200

19. Force which does not act on the connecting rod is ______

Radial forceCoriolis forceInertia force of connecting rodWeight of connecting rod

20. When the work is done on the gases, which of the following effect is observed on the turning moment diagram?

Formation of negative loopFormation of an infinite loopFormation of positive loopFormation of no loop

21. When engine torque is more than mean resisting torque, then the flywheel _______

Has accelerationHas uniform velocityHas 0 velocityHas retardation

22. If E = Mean kinetic energy of the flywheel, C_S = Coefficient of fluctuation of speed and Δ E = Maximum fluctuation of energy, then

ΔE = 2 E × CSΔE = E × CSΔE = E / CSΔE = E2 × CS

23. For a multicylinder engine, the coefficient of fluctuation of speed would vary with _________

Number of cylindersRemains unaffectedLength of connecting rodInput temperature

24. For a steam engine, the following data is given:
Piston diameter = 0.24 m, length of stroke = 0.6 m, length of connecting rod = 1.5 m, mass of reciprocating parts = 300 kg, mass of connecting rod = 250 kg; speed of rotation = 125 r.p.m ; centre of gravity of connecting rod from crank pin = 0.5 m ; Kg of the connecting rod about an axis through the centre of gravity = 0.65 m
calculate inertia force at θ=30 degrees from IDC.

19064 N19032 N19000 N20064 N

25. 4-stroke engine has one power stroke per 2 revolutions hence turning moment diagram is uniform.

TrueFalseDon't KnowMaybe