Two stroke enging

Two stroke enging

1. Presented By Subrata Kumar Sarker B.S.C in Textile Engineering (Evening) ID: 151014002

2. My Presentation Topic Is Two Stroke Engine

3. Learning Outline

4. Sir Dugald Clerk Frist Two stroke patented in 1881 Sir Dugald Clerk KBE, FRS (1854, Glasgow-1932, Ewhurst , Surrey) was a Scottish engineer who designed the world’s first successful two-stroke engine in 1878 and patented it in England in 1881.

5. A two stroke engine has one working stroke after every revolution of the crank shaft. It means the suction compression expansion and exhaust takes place during two stroke of the piston. Different parts of it Glow plug, Cylinder head, Intake port C onnecting rod, Crankshaft, C ooling fans, Piston, transfer port & crankcase

6. Intake/Suction stage : In this stage the piston while going down towards bottom dead center uncovers both the transfer port & the exhaust port. The fresh fuel-air mixture flows into the engine cylinder from the crank case. Compression stage : In this stage the piston while moving up first covers the transfer port and then exhaust port. After that the fuel is compressed as the piston moves upward. In this stage the inlet port opens and the fresh fuel-air mixture enters into the crank case.

7. Expansion/Power Stage : Shortly before this piston reaches the top dead center the charge is ignited with the help of a spark plug. It suddenly increase the pressure & the temperature of the products of combustion. But the volume practically remains constant. Due to rise in the pressure the piston is pushed downwards with a great force. The hot burnt gases expand due to high speed of the piston. During this expansion some of the heat energy produced is transformed into mechanical work. Exhaust stage : In this stage the exhaust port is opened as the piston moves downwards the products of combustion from the engine cylinder are exhausted through the exhaust port into the atmosphere. This completes the cycle and the engine cylinder is ready to suck the charge again.

8. Four Stroke E ngine Two Stroke E ngine There are two types of stroke engine

9. Four Stroke Two Stroke One cycle completed in every revolution of crank shaft No valves but ports are used for admission and exhaust Less moving parts Less maintenance Light in weight Less expensive Compeer between four & two stroke engine One cycle completed in every 2 revolution of the crank shaft Valves are used for charge admission and exhaust More moving parts More maintenance Heavy in weight More expensive

10. Advantage of two stroke engine One cycle completed in every revolution of crankshaft It is more compact required less space and lighter in weight than four stroke engine The design & construction is much simpler than four stroke engine Easy to manufacture & low cost

11. Disadvantage of two stroke engine Flow is choked during combustion due to high pressure differential and small clearance area The friction and wear at the ball piston cylinder wall sliding interface Leakage through the ball piston cylinder gap is a significant factor for engine deficiency at low speed