Evaluation of the corrections methodologies for improving the ignition delay time calculation in hydrogen/air mixtures using a design of experiments approach

The ignition delay time is one of the fundamental combustion parameters for fuel characterization. For this reason, adequate prediction is essential, particularly for alternative fuels, to broaden the spectrum of implementation. However, significant deviations exist between the values calculated numerically concerning the experimental ones under moderate- and low-temperature conditions. Different types of chemical and physical principles corrections have been proposed to solve this problem. In the present study, different corrections were evaluated using an experimental design approach, along with additional factors like pressure, temperature, and the reaction mechanism. The results of the analysis of variance make it possible to establish that there is no synergistic effect when combining physical and chemical corrections. The average reduction in the response variable when individual corrections were applied was 3.7%, whereas a slight increase in the same quantity was observed when the approaches were applied simultaneously. For a pressure of 0.5 MPa, the chemical and physical approaches to improve the ignition delay time prediction allow for achieving a decrease in response variable of 6.5% and 26.4%, respectively. However, the trend is the opposite at high pressure, and the deviations increase for both corrections. In addition, the values of the sum of squares evidenced that the interactions between the corrections and the thermodynamic conditions present incidence levels on the deviations between experimental and numerical data greater than those exposed by each isolated factor.