Development of a Simulation Code for Hydrogen Fuelled SI Engines

Hydrogen is an attractive alternative energy carrier, which could make harmful emissions, global warming and the insecurity concerning oil supply a thing of the past. Hydrogen internal combustion engines can be introduced relatively easily, from a technological as well as from an economic point of view. This paper discusses the development of a model for the combustion of hydrogen in spark ignition engines, which has lead to a simulation program that can assist the optimization of these engines. The importance of a laminar burning velocity correlation taking stretch and instability effects into account is shown. The effects are particularly strong for the highly diffusive hydrogen molecule. In this paper, a laminar burning velocity correlation published previously by two of the authors is combined with a number of turbulent burning velocity models in a quasi-dimensional two-zone combustion model framework. After calibration of the combustion model for a reference condition, simulation results are compared with experimental cylinder pressure data recorded on a single cylinder hydrogen engine. Correspondence between simulation and measurement is shown for varying equivalence ratio, ignition timing and compression ratio. All models performed well for varying ignition timings and compression ratios; the real test proved to be the ability of the models to predict the effects of a varying equivalence ratio, this lead to a clear distinction in the models.