Modeling Homogeneous, Stratified, and Diffusion Combustion in Hydrogen SI Engines Using the Wiebe Approach

The use of hydrogen as a fuel for piston engines enables environmentally friendly and efficient operation. However, several challenges arise in the combustion process, limiting the development of hydrogen engines. These challenges include abnormal combustion, the high burning velocity of hydrogen-enriched mixtures, increased nitrogen oxide emissions, and others. A rational organization of hydrogen combustion can partially or fully mitigate these issues through the use of advanced methods such as late direct injection, charge stratification, dual injection, jet-guided operation, and others. However, mathematical models describing hydrogen combustion for these methods are still under development, complicating the optimization and refinement of hydrogen engines. Previously, we proposed a mathematical model based on Wiebe functions to describe premixed and diffusion combustion, as well as relatively slow combustion in lean-mixture zones, behind the flame front, and near-wall regions. This study further develops the model by accounting for the combined influence of the mixture composition and engine speed, mixture stratification, and the effects of injection and ignition parameters on premixed and diffusion combustion. Special attention is given to combustion modeling in an engine with single injection and jet-guided operation.