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CAREER POINT UNIVE

SUBMITTED BY-Varun kumar meenaUID-K12020B.TECH 3RD YEARBRANCH-MECHANICAL

SUBMITTED TO-MR. Amardeep Kumar

Ass. Prof. OF ELECTRICAL DEPTT

MAJOR ASSIGNMENTEnvironmental friendly two stroke

engine

~ Function of Two Stroke Petrol EngineThe function of a

two stroke petrol engine is to deliver power to the crank shaft joined with the rotary wheel with the use of working substance as Petrol (Gasoline) entered through inlet port (Carbureter) which is ignited inside the cylinder through the spark plug and remaining substance is released through exhaust port. This whole process is completed in one revolution of flywheel.

Construction of Two Stroke Petrol Engine

Beginning of First Stroke When the piston moves

upward a partial vaccum is created in the crank case until its lowers edge uncovers the inlet port completely as shown in Fig.(A)

The pressure difference set

up between the atmosphere and crankcase will suck the petrol-Air mixture through the carburetor fitted to inlet port into the crank case.

The suction will be continued till the inlet port is covered by the piston during its next downward stroke.

After the inlet port is covered by the piston as shown in the Fig. (B) , its further downward motion will compress the Charge ( Petrol-Air Mixture ) in the crankcase upto the top edge of the piston uncovers the transfer port as shown in fig. (B).

The Compressed charge flows from the crank case to the cylinder through transfer port.

The electric spark ignites the compressed charge . The combustion of charge will release hot gases which increase the pressure and temperature in the cylinder .

The high pressure combustion gases force the piston downwards .The piston performs the power stroke till it uncovers the exhaust port as shown in the figure. (B)

The combustion gases which are at a pressure slightly higher than the atmosphere pressure escape through the exhaust port .

The piston uncovers the transfer port .The fresh charge which enters the cylinder pushes the burnt gases so more amount of exhaust gases comes out .

This sweeping out of exhaust gases by the incoming fresh charge is called scavenging

In this stroke the piston moves from BDC to TDC . It covers the transfer port as shown in the Figure ( c ) .

SECOND STROKE

After the above situation the supply of the charge is stopped and then when it moves further up it covers the exhaust port completely as shown in Fig.(D) stops scavenging.Upward motion of the piston will compress the charge in the cylinder.After the piston reaches TDC the first stroke repeat again.

Thank You