This is the topic of Elements of mechanical engineering. Here are the all cycles which is important for our syllabus

1. Air Standard cycles - Otto, Diesel, Dual
and Brayton Cycle
Dr. Rohit Misra
Associate Professor
Department of Mechanical Engineering
Engineering College Ajmer

2. Otto cycle

3. Otto Cycle: Air Std. Eff. & mean effective pressure

7. Diesel cycle

8. Diesel Cycle: Air
Std. Eff. & mean
effective pressure

13. Dual cycle

14. Dual Cycle:
Air Std. Eff. &
mean effective
pressure

21. Important Terms in I.C. Engine
Top Dead Centre and Bottom Dead Centre

22. Important Terms in I.C. Engine (Contd.)
 Stroke length and Bore
 Displacement or Swept volume
 Cubic capacity or Engine Capacity
 Clearance volume
 Compression ratio

23. Cross-section of Spark Ignition engine

24. Working of 4 Stroke S.I. Engine

25. Working of 2 Stroke S.I. Engine

26. Comparison of SI and CI Engine

27. Comparison of SI and CI Engine (Contd.)

28. General expression for Power
Power=(pmALN)/n
 where pm= mean effective pressure, N/m2
 L=length of stroke, m
 A=Area of piston, m2
 N=rotational speed of the engine rev/sec
 n=number of revolutions required to complete one engine cycle
n=1 for two stroke engine
n=2 for four stroke engine

29. Comparison of 4-Stroke and 2-Stroke Engine

30. Comparison of 4-Stroke and 2-Stroke Engine (Contd.)

31. First Law Analysis of Engine cycle

32. Engine Performance Parameters
 Indicated Thermal Efficiency
 Brake Thermal Efficiency
 Mechanical Efficiency
 Volumetric Efficiency
 Relative efficiency or efficiency ratio
 Mean effective pressure
 Specific Fuel consumption
 Air Fuel ratio

33. Indicated Power, Brake Power and Friction Power
Brake power (b.p.): Power developed by the engine at the output shaft.
b.p.=2 πNT
Where T is torque in Nm and N is rotational speed in rps.
T=Wr
Where W is the force at dymaometer in N and r is radius in m.

34. Indicated Power, Brake Power and Friction Power
Indicated Power (i.p.): Total power developed by combustion of fuel in
combustion chamber is, however, more than b.p.
Friction power (f.p.): Power consumed in overcomingfriction between moving
parts, inducting the air, exhausting the products of combustion, drive
auxiliary devices like water pump and lubricating oil pump etc.
b.p.=i.p-f.p.

35. Indicated Thermal Efficiency
Ratio of energy in the indicated power to the fuel energy
it
f
ip
m CV
 


36. Brake Thermal Efficiency
Ratio of energy in the Brake power to the fuel energy
bt
f
bp
m CV
 


37. Mechanical Efficiency
Ratio of Brake power to indicated power.
mech
bp
ip
 

38. Volumetric Efficiency
Ratio of the air actually inducted at ambient conditions to the swept volume of the
engine. Volumetric efficiency can be calculated considering mass or volume of air. It is
preferable to use mass basis.
vol
s
V
V
 

39. Mean Effective Pressure
Hypothetical pressure which is thought to be acting on the piston throughout the
stroke that results in the same amount of indicated or brake work produced by the
engine.
Scales out effect of engine size. It is true indication of the relative performance
of different engines.
where pim=indicated mean effective pressure, N/m2
L=length of stroke, m
A=Area of piston, m2
N=rotational speed of the engine rev/sec
n=number of revolutions required to complete one engine cycle
n=1 for two stroke engine
n=2 for four stroke engine

40. Specific fuel consumption
Amount of fuel consumed per unit of power developed per hour.

41. Energy Distribution

42. THANKS