Toward H ₂ ICE: Experimental and computational characterization of hydrogen injection, mixing, and combustion

Hydrogen-fueled internal combustion engines (H 2 ICE) have great potential as future carbon-free transportation, especially in heavy-duty applications, but the implementation in real vehicles has not yet been demonstrated due to a number of technical challenges. One of the most important issues is the design of hydrogen injector systems that can provide the needed amount of fuel into the combustion chamber with rapid mixing with the main chamber gases to achieve a near homogeneous mixture, in order to ensure stable combustion without anomalies such as pre-ignition and knocking. The present study provides an overview of the ongoing FUELCOM4 project with KAUST and Saudi Aramco in an effort to enhance our knowledge of hydrogen injection, mixing, and combustion characteristics by utilizing high-fidelity laser diagnostics and simulations. First, hydrogen jet injection and mixing characteristics are investigated in a high-pressure constant volume chamber experiment with accompanying simulations for validation. Jet penetration and dispersion characteristics depending on different injector configurations are examined. Recent developments in advanced laser diagnostic techniques to quantify the hydrogen fuel distribution are also discussed. Finally, parametric studies of the effects of jet dispersion and mixing on engine combustion characteristics are presented.