Indicator Diagram or P-V Diagram (Actual) for a Two Stroke Cycle Petrol Engines

Indicator Diagram or P-V Diagram (Actual) for a Two Stroke Cycle Petrol Engines Points : Indicator Diagram or P-V Diagram (Actual) for a Two Stroke Cycle Petrol Engines Shows the indicator diagram of a two stroke cycle petrol engine. The suction is shown by the line 1.2.3 (i.e. from the Instant inlet port opens end inlet port close). We know that during the Suction stage, the exit poll is also open. In the first hail of suction stage the volume of fuel air mixture and burnt gases increases. This happens as the piston moves from I to 2 (i.e. B.D.C.). In the second half of the suction stage the volume of charge and burnt gases decreases. This happen as the piston moves upwards from 2 to 3. A little beyond 3, the exhaust port closes (EPC) at 4. Now the charge inside the engine cylinder is compressed which is shown by the line 4.5. At the end of the compression, there is an increase in the pressure inside the engine cylinder. Shortly before the end of compression (i.e. TDC) the charge is ignited (IGN) with the help of spark plug as shown in the figure. The sparking suddenly increases pressure and temperature of the production of combustion. Bu the volume, practically, remains constant as shown by the line 5.6. The expansion is shown by the line 6.7. Now the exhaust port open (EPO) at 7, and the burnt gases are exhausted into the atmosphere through the exit valve. it reduces the pressure. As the piston is moving towards BDC, therefore volume of burnt gases increases from 7 to 1. At 1, the inlet port opens (IPO) and the suction starts.