4-Stroke Theoretical (Otto) Cycle Flashcards
1
Q
What is the name of the 4 different stokes?
A
- Induction
- Compression
- Power
- Exhaust
2
Q
What happens during the 4 different strokes?
A
- Induction- Inlet valve opens, piston descends, mixture is sucked into the cylinder
- Compression- All valves open, piston ascends, mixture is compressed to maximise pressure
- Power- All the valves close, mixture ignites, piston is pushed down by the expanding gases
- Exhaust- Exhaust valve opens, piston ascends, waste gases are expelled
3
Q
What does the term “stroke” mean?
A
The distance the piston travels between the highest and lowest point of the cylinder
4
Q
What is the term for the “highest point” within the cylinder?
A
TDC (Top Dead Centre)
5
Q
What is the term for the “lowest point” within the cylinder?
A
BDC (Bottom Dead Centre)
6
Q
When does ‘Ignition’ occur?
A
At TDC between Compression and Power
7
Q
Explain what happens during at ‘Induction’
A
- Inlet valve opens
- Mixture is sucked into the cylinder
- Piston travels from TDC to BDC
- Volume increases, pressure decreases, temperature decreases
- Crankshaft rotates 180˚
8
Q
Explain what happens during at ‘Compression’
A
- Inlet valve closes
- Piston ascends, moving from BDC to TDC
- Volume decrease, pressure increase, temperature increase
- Crankshaft rotates 360˚
9
Q
Explain what happens during ‘Power’
A
- Both valves close
- Piston descends from TDC to BDC due to gases pushing the piston
- Volume increases, pressure reduces, temperature reduces
- Crankshaft rotates 540˚
10
Q
Explain what happens during ‘Exhaust’
A
- Exhaust valve opens
- Piston ascends from BDC to TDC
- Volume decrease, pressure increase, temperature increase
- Crankshaft rotates 720˚
