Ice c-1 to 20 fundamentals

1. SI ENGINES

2. FOUR STROKE

3. INTERNAL COMBUSTION ENGINESFOUR STROKE

4. TWO STROKE

5. TWO STROKE

6. Wankel engines
• 3 LOBE ROTOR WHICH IS
DRIVEN ECCENTRICALLY IN A
CASING & 3 VOLUMES ARE
TRAPPED BETWEEN THE ROTOR
AND THE CASING. THESE
VOLUMES PERFORM
INDUCTION, COMPRESSION,
POWER & EXHAUST STROKES
SEPERATELY.
• SEAL WEAR & HEAT TRANSFER
ARE PROBLEM AREAS
ROTARY

7. Wankel Engine Four Strokes

8. Wankel Engine - Four Strokes

9. Wankel Engine Details

10. COMPRESSION RATIO
• It is the ratio between the cylinder volume
above the piston at BDC (Vbdc) and the volume
above the piston at TDC (Vtdc). Vbdc is Vtdc plus
the swept cylinder volume (Vsw).
• This is the ratio between the total volume to
the clearance volume in IC engines
compression ratio = ────────
Vsw + Vtdc
Vtdc

11. INTERNAL COMBUSTION ENGINES

12. Cylinder Swept Volume or Displacement
Volume (Vc
)
Vc
= Cylinder Area x Stroke Length
Vc
= Ac
x L = (π/4.dc
2
) x L
where:
Vc
= cylinder swept volume [usually cm3
(cc) or L ]
Ac
= cylinder area [usually cm2
or mm2
]
dc
= cylinder diameter [usually cm or mm]
L = stroke length (distance between the TDC and
BDC) [usually cm or mm]

13. BORE/STROKE RATIO
The ratio between the cylinder diameter/cylinder stroke
called “bore/stroke” ratio.
•A “bore/stroke" =1 is called square engine
•A “bore/stroke" >1 is called over square engine, and is
used in automotive engines
•A “bore/stoke” <1 is called an under square engine, and
is used in tractor engines
Engine Swept Volume (Ve):
Ve
= Combined Swept Volumes of all Engine Cylinders
Ve
= n Vc
Ve
= n Ac
x L = (π/4.dc
2
) x L where n= no of cylinders

14. HORSEPOWER
• Power is measured in many other units
besides horsepower, depending on location
and application. Watts (W) and kilowatts (kW)
are in common use worldwide. Less common
measures include British thermal units per
hour (Btu/hr) and foot-pound force per
minute (ft-lbf/min).

15. DEFINITION OF HORSEPOWER
• Standard mechanical horsepower is defined
as about 33,000 ft-lbf/min, or 745.7 watts.
However, there are other definitions of
horsepower. Some of these definitions refer
to different ways of measuring power for a
specific application.

16. Indicated Horsepower
• Indicated horsepower (ihp) is the power
developed inside the combustion chambers
during combustion. Indicated horsepower is
always higher than brake horsepower, as
some of the power developed in the cylinders
is lost in overcoming the internal friction in
the engine
• It is calculated from the pressures developed
in the cylinders, measured by a device called
an engine indicator – hence the name
indicated horsepower.

17. Indicated Horsepower
• Indicated Horsepower,ihp:
ihp = pmL a n
33,000
Where:
pm= mep, lb/in2
L = stroke, ft
a = piston area, in2
n = number of cycles per minute
33000 = ft-lb/min / hp (definition)