Experimental quantification and assessment of combustion anomalies under defined operating conditions of a heavy-duty hydrogen engine

Abstract Hydrogen internal combustion engines have the potential to become a key zero-emission propulsion system of the future. Especially the use in heavy-duty applications seems promising. However, some challenges remain, one of them being the tendency of these engines towards combustion anomalies. The present paper proposes a methodology for the quantification and evaluation of combustion anomalies occurring under varying operating conditions on an engine test bench. For this, a test procedure is defined to detect irregularities in a systematic way. The classification of the anomalies is conducted through a post-processing routine, which utilizes appropriate parameter limit values. The findings of this study indicate that engine anomaly behavior is strongly influenced by ambient conditions, most notably by elevated charge air and coolant temperatures. Furthermore, ignition timing exerts a significant additional effect. This paper also addresses the reproducibility and validity of the test procedure for real-life operation. All research activities conducted in this paper were performed under the scope of the COMET project Hylley.