An Experimental Analysis of the Knock Response of Di erent Stoichiometric Mixtures of Gasoline-Natural Gas to Various Engine Speeds

Gasoline causes engine knock in higher compression ratios due to having lower spontaneous ignition temperature. natural gas (ng) has a higher octane number and is a proper fuel in terms of anti-knock properties; however, using it as the engine fuel results in a increases the emission of some exhaustgases due to lower burning velocity and gaseous nature and decline in the power of the engine. using the mixture of gasoline and ng with gasoline as the predominant fuel can compensate the decline of the engine power and prevent the occurrence of engine knock. bearing this in mind, in the presentstudy, 4 dierent combinations of gasoline and ng consisting of 100%, 90%, 80%, and 70% gasolineand the rest ng (ga100, ga90, ga80, and ga70, respectively) were experimentally investigated using a single cylinder si research engine at the equivalence ratio of 1.0, compression ratio of 11, and the engine speeds of 1500, 1800, and 2100 rpm.