An experimental study of uncertainty considerations associated with predicting auto-ignition timing using the Livengood-Wu integral method

The application of the Livengood-Wu (LW) integral method as a tool to estimate knock onset in spark ignited (SI) engines and combustion phasing advanced compression ignition (ACI) has been demonstrated through simulations several times. In this study, effect uncertainties associated with parameters required for LW method, when used model based control timing an ACI engine, were experimentally studied using five full boiling range gasoline fuels. As first step, was applied experimental data from rapid machine it found that ability predict very sensitive performance chemical kinetic each fuel. subsequently single-cylinder engine simple approximations input parameters, predicted time significantly different actual start combustion. Systematic evaluation various parametric conducted thereafter showed uncertainty cylinder charge temperature greatest influence. Improved methods estimating are proposed account previously determined corrections, enable use timing.