Mean effective pressure oscillations in an IC-SI engine after the addition of hydrogen-rich gas

Fluctuations during the combustion of hydrogen-enriched gasoline in an Internal Combustion Spark Ignition (IC-SI) engine were investigated. The energy share of the hydrogen-rich fuel for the engine was varied as 0%, 5%, 10%, and 20%, respectively. The cyclic combustion pressure was measured and its cyclic oscillations were expressed by indicated mean effective pressure per cycle. The statistical and multifractal analyses applied to the corresponding time series showed considerable changes in the engine dynamics for hydrogen percentages ranging from 5% to 20%. The mean indicated pressure and the maximum pressure in the combustion chamber of the engine running under steady conditions were measured.