Development and Validation of a Combustion Model for a High-Performance H2 Engine Considering Thermo-Diffusive Instability Effects

Abstract

This study presents the development and validation of a predictive 0D/1D combustion model for a high-performance direct injection hydrogen spark-ignition engine, explicitly incorporating thermo-diffusive instability (TDI) effects through a physics-based formulation derived from linear flame stability theory and DNS-informed scaling laws. A laminar flame speed correlation obtained from detailed chemical kinetics is enhanced via an instability growth-rate model and embedded within an entrainment-based turbulent combustion framework, coupled with an Extended Zeldovich mechanism for NOx prediction. The model is validated against experiments covering 2000–7500 rpm, loads up to 28 bar IMEP-H, and relative air-to-fuel ratio between 1.2 and 3.0. The results demonstrate that instability-aware modeling is essential for accurate ultra-lean combustion prediction, where conventional approaches severely underpredict burning rates. Across the full operating map, combustion phasing is predicted within ±3 CAD and NOx with an average error of 20%, enabling robust system-level simulation and virtual calibration of high-performance hydrogen engines.