Study of laminar burning speed and calibration coefficients of quasi-dimensional combustion model for hydrogen enriched compressed natural gas fueled internal combustion engine along with exhaust gas recirculation

Utilization of hydrogen fuel in internal combustion engine is regarded as a good choice due to its zero-carbon emission. The experiments have been performed under a wide range of operating conditions and the traces of in-cylinder pressures are obtained. The authors have formulated five laminar burning speed correlations (HCNG/N-2, HCNG/N-2/P, HCNG/CO2/T, HCNG/CO2/P & HCNG/CO) from the previous experimental work 25,31,33,31,38] while, two correlations (HCNG/N-2/O-2/T & HCNG/CO/CO2/T) have been imported from the earlier research work 132,35 The iterations of these models have been staged in the quasi-dimensional combustion program of HCNG engine along with the exhaust gas recirculation but, results were un-satisfactory. Therefore, another laminar burning speed correlation (HCNG/N-2/CO2/T) has been developed to improve the quasi-dimensional combustion model of HCNG fuel mixture along with the EGR technique. The kinetic GRI Mech3.0 mechanism has been utilized for the prediction of laminar burning speed of HCNG fuel mixtures at different hydrogen fractions 0 to 20% by volume in compressed natural gas, EGR ratios (0-0.3) and inlet temperatures (300-350 K). The effect of EGR ratio on the laminar burning speed in HCNG fuel mixture is introduced as the simultaneous impact of CO2 and N-2 dilution of gases according to the balance chemical equation at stoichiometric condition. The presented model (HCNG/N-2/CO2/T) is best suited for the quasi-dimensional combustion code of HCNG fuel mixture along with the exhaust gas recirculation as mean of the sample points of Taylor length & turbulent intensity coefficients are closer to 1 and minimum absolute percentage error for the indicated mean effective pressure.

Automated summary

The study investigates the utilization of hydrogen fuel in internal combustion engines and proposes various laminar burning speed correlations for HCNG fuel mixtures. The effect of Exhaust Gas Recirculation (EGR) on the laminar burning speed is also explored, with a new correlation developed to improve the quasi-dimensional combustion model. The GRI Mech3.0 mechanism is employed for predicting laminar burning speeds under different operating conditions, showing promising results for HCNG fuel mixtures.