Abstract
To investigate the influencing factors and influence patterns of cooled exhaust emission with small ejection ratio during engine operation in a climate laboratory, a typical low bypass ratio engine was selected as the research object. Using numerical simulation methods and considering engine exhaust composition and variable specific heat fluid properties, the effects of exhaust duct diameter, pipe inlet distance, and water spray cooling on the emission characteristics of engine exhaust with small ejection ratio were analyzed. The results indicate that: the ejection ratio exhibits a linear positive correlation with exhaust duct diameter, increasing as the duct diameter increases; pipe inlet distance has a minor effect on the ejection ratio, but an optimal pipe inlet distance exists; water spray cooling disrupts the shock wave structure of the ejector flow field, reduces the jet velocity deficit, and increases the ejection ratio.
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