An analysis of the factors that limit the improvement in thermal efficiency at higher compression ratios was performed with both thermodynamic calculation and experiment. The results showed that the major factors were cooling loss and unburned fuel. Both of these factors increase with smaller swept volume, larger S/V ratio combustion chamber, and lower engine speed and load. These effects explain the observation that thermal efficiency peaks at relatively low compression ratio.
Factors Limiting the Improvement in Thermal Efficiency of S. I. Engine at Higher Compression Ratio
Sae Technical Papers
SAE International Congress and Exposition ; 1987
1987-02-01
Aufsatz (Konferenz)
Englisch
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