CLASSIFICATION OF IC ENGINES

IC ENGINE

THE ENGINES IN WHICH THE COMBUSTION POWERING THE ENGINE TAKES PLACE INTERNALLY WITHIN THE ENGINE CYLINDER IS KNOWN AS INTERNAL COMUSTION ENGINES

LETS DISCUSS ABOUT ITS CLASSIFICATION IN THIS BLOG.

CLASSIFICATION OF IC ENGINE

 1.According to ignition System:

a.Compression Ignition Engine (C. I. Engine):

In this type of engine, the heat of the compressed air itself ignites the fuel.

b.Spark Ignition Engine (S. I. Engine):

In this type of engine (Otto engine), the fuel is ignited by the spark produced by a high-tension electrical circuit.

2. According to Strokes/Cycle 

a) Four Stroke Engine:

An engine, which needs 4 strokes of the piston (2 in and 2 out) to complete one cycle, is called Four-stroke engine

b) Two Stroke Engine:

An engine that needs only 2 strokes of the piston (1 in and 1 out) to complete one cycle is called Two-stroke engine.

3.According to Piston Connection.

(a)   Trunk Piston Type:

The piston is connected directly to the upper end of the connecting rod

      (b) Cross Head Type:

The piston fastens to a vertical piston rod whose lower end is attached to a ‘cross head’, which slides up and down in guides

trunk piston vs cross head 

4.According to method of Charging:

a.Natural aspirated Engine:

The vacuum is created when the piston moves away from the combustion space draws in the fresh charge.

b.Supercharged Engine:

The charge is admitted into the cylinder at a higher than atmospheric pressure.

5. According to Speed.

1. Slow Speed Engines: 100 to 150 r.p.m.

2. Medium Speed Engines: 300 to 1000 r.p.m.

3. High Speed Engines: More than 1000 r.p.m.

6.According to Bore/Stroke Ratio

1. Square Engine: If bore/stroke is about one, crankshaft web dimensions become less compared to journal and crankpin.

2. Over Square Engines (Short Stroke): If bore/stroke > 1, web dimensions (less height, more thickness) are such that webs will be weak. So generally over square engines are not used.

3. Long Stroke Engines: Generally, engines have stroke/bore >1. This gives crankshafts of good strength. Most common ratio is stroke/bore = 2^. 0: 2^.2.

4. Super-long Stroke Engines: To have better propeller efficiency and better combustion even with lower grade fuels, lower RPM engines with longer strokes are gaining popularity. These engines have stroke/bore ratio = 3. 

7.According to Cylinder Arrangement:

a. Cylinder-in-Line Arrangement:

This is the simplest and most common arrangement, with all cylinders arranged vertically in line.

                      inline engine arrangement

b.V - Arrangement:

If an engine has more than eight cylinders, it becomes difficult to make a sufficiently rigid frame and crankshaft with an inline arrangement. Also engine becomes quite long and takes up considerable space. So V-arrangement is used for engines with more cylinders, (generally 8, 12, 16) giving about half-length of engine, more rigid and stiff crankshaft, less manufacturing and installing cost. Angle between two

‘Banks’ is kept from 30* to 120*

V engine arrangement

c. Flat Arrangement:

It is a V-engine with angle between the banks increased to 180*. Generally, it is used in trucks, buses, rail cars, etc. where there is little headroom

flat engine arrangement

d. Radial Arrangement:

In a radial engine, all the cylinders are set in a circle and all point towards the center of the circle. 

radial engine arrangement

 

Now being understood the various classification of ic engine , lets know more about THE VARIOUS CYCLE OF EVENTS DURING ENGINE OPERATION . click here to know more