Quantitative evaluation of n-butane concentration on knock severity of a natural gas heavy-duty SI engine

Knocking combustion of a natural gas spark ignition engine with the addition of n-butane was investigated. Specially, the effects of n-butane concentration on knock severity were quantitatively evaluated with engine full-load at various engine speeds. The results show that with an increase in n-butane concentration, the peaks of in-cylinder pressure and heat release rate increase, combustion duration is shortened, and CA50 is advanced. At high...