Introduction to Otto Cycle| Four-Stroke, Five-Event Cycle

Strokes - the movement of the piston (TDC to BDC and vice versa) 1. Intake Stroke 2. Compression Stroke 3. Power Stroke 4. Exhaust Stroke Events 1. Intake - the air-fuel mixture is drawn inside the combustion chamber via the intake valve 2. Compression - the mixture is compressed for optimum burning 3. Ignition - electric spark from the spark plug ignites the fuel-air mixture 4. Power - burned and expanding gases drives the piston down to the TDC 5. Exhaust - burned gases are forced out of the combustion chamber via the exhaust valve Otto Cycle 1 - 2: Isentropic Compression 2 - 3: Constant volume addition of heat 3 - 4: Isentropic Compression 4 - 1: Constant volume rejection of heat