Four Stroke Piston Engine Video Lessons

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# Problem: The Otto-cycle engine in a Mercedes-Benz SLK230 has a compression ratio of 8.8.Part A. What is the ideal efficiency of the engine? Use γ=1.40.Part B. The engine in a Dodge Viper GT2 has a slightly higher compression ratio of 9.6. How much increase in the ideal efficiency results from this increase in the compression ratio?

###### FREE Expert Solution

Part A:

Ideal efficiency:

$\overline{){\mathbf{e}}{\mathbf{=}}{\mathbf{1}}{\mathbf{-}}\frac{\mathbf{1}}{{\mathbf{\left(}\frac{{\mathbf{V}}_{\mathbf{1}}}{{\mathbf{V}}_{\mathbf{2}}}\mathbf{\right)}}^{\mathbf{\gamma }\mathbf{-}\mathbf{1}}}}$

V1/V2 is the compression ratio.

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###### Problem Details

The Otto-cycle engine in a Mercedes-Benz SLK230 has a compression ratio of 8.8.

Part A.

What is the ideal efficiency of the engine? Use γ=1.40.

Part B.

The engine in a Dodge Viper GT2 has a slightly higher compression ratio of 9.6. How much increase in the ideal efficiency results from this increase in the compression ratio?