Comparison of CI and SI engine and calibration of Single cylinder CI-Engine

Aim:-> To compare SI and CI engine and perform basic calibration of single cylinder CI engine.

Comparison of SI V/S CI Engine model:

SI Engine	CI Engine
SI engine is internal combustion engine that operates on the principle of spark ignition.	CI engine is internal combustion engine that operates on the principle of compression ignition.
Low compression ratio needed.	Higher compression ratio needed.
High thermal efficiency.	Low thermal efficiency.
Generates lesser noise and vibration as compared to CI engine.	Generates high noise and vibrations.
Weight is low.	Weight is high.
Gasoline is used as fuel.	Diesel is used as fuel.
Cost is cheaper.	Cost is high.
Generates high speed.	Generates low speed.
Works on Otto cycle.	Works on Diesel cycle.
Volume to power ratio is less.	Volume to power ratio is high.
Maintenance cost is low.	Maintenance cost is high.
Applications: Light duty vehicles like motor-cycles, cars.	Applications: Heavy duty vehicles like buses, trucks.

~Circuit Model:

Fig: SI engine model

Fig: CI engine model

SI Engine	CI Engine
Fig: Cylinder geometry
Fig: Fuel injection properties
Fig: Inlet environmental conditions

~Result for RPM 1800:

SI Engine	Ci Engine
Fig: PV Diagram
Fig: Incylinder temperature
Fig: Incylinder pressure

Calibration of single cylinder CI Engine:

~Problem setting:

Cases:

Cylinder geometry:

Injection parameter:

Valve lifts:

Fig: Inlet valve	Fig: Outlet valve

~Result:

Effect of varying crank-angle degrees (duration) of the main diffusion burn:

Case:

Cylinder geometry:

Injection parameter:

Direct-Injection Diesel Wiebe Combustion Model:

Fig: Main duration of 20	Fig: Main duration of 35	Fig: Main duration of 50

~Result:

Conclusion:

Hence, CI engine model is studied and difference in SI engine & CI engine is stated.