Two Stroke Cycle Diesel Engines

Two Stroke Cycle Diesel Engines Points : Two Stroke Cycle Diesel Engines, Suction, Compression, Expansion, Exhaust A two-stroke cycle diesel engine also has on working stroke after every revolution of the crankshaft. All the four stages of a two stroke cycle diesel are described here: 1. Suction In this stage the piston, while going down uncovers the inlet port (I) and fresh air flows into the engine cylinder from the crank case. 2. Compression In this stage the piston, while moving up, first covers the inlet port, and then exhaust port. After that the fuel is compressed as the piston moves upwards as shown in. In this stage the valve (V) opens and the fresh air enters into the crankshaft. 3. Expansion Shortly before the piston reaches the TDC (during compression stroke), the fuel oil is injected in the form of very fine spray into the engine cylinder through the nozzle (N) known as fuel injection valve. At this moment, temperature of the compressed air is sufficiently high to ignite the fuel, It suddenly increases the pressure and temperature of the products of combustion. The fuel oil is continuously injected for a fraction of the crank revolution. The fuel oil is assumed to be burnt at constant pressure. Due to increase in pressure, the piston is pushed with a great force. The hot burnt gases expand due to high speed of the piston. During the expansion, some of heat energy produced is transformed into mechanical work. 4. Exhaust In this stage, the exhaust valve is opened and the piston moves downwards. The products of combustion from the engine cylinder are exhausted through exhaust valve (EO) into the atmosphere. This completes the cycle. The engine cylinder is ready to suck the air once again.