What is the difference between the Atkinson cycle and the Miller cycle?

[McAvery]

Here are the differences between the Atkinson cycle and the Miller cycle: 1. Different connecting rod mechanisms: The Atkinson cycle has a complex connecting rod mechanism, while the Miller cycle does not. The Miller cycle changes the compression ratio by altering the intake valve closing timing. 2. Different piston compression methods: The Atkinson cycle compresses through the connecting rod mechanism. In the Miller cycle, the intake valve closing is delayed during piston compression, allowing some of the air-fuel mixture drawn into the cylinder during the intake process to flow back into the intake manifold, thereby changing the compression ratio. 3. Overall perspective: Both cycles aim to achieve an expansion ratio greater than the compression ratio, but they employ different methods. The Atkinson cycle achieves this by altering the piston stroke through various mechanisms, while the Miller cycle accomplishes it by delaying the intake valve closing.