• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.3
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• pp.129-139
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• 1995

This study investigates the combustion characteristics of methane-hydrogen-air premixture in a constant volume combustion chamber. Primary factors of the combustion characteristics of methane- hydrogen-air premixture are the equivalence ratio and hydrogen supplement rate. In the case of $\phi$= 1.1, maximum combustion pressure and heat release rate have peaks, and they increase as the initial pressure and hydrogen supplement rate increase. The total burning time is also the shortest at the $\phi$= 1.1, it shorten by lowering the initial pressure and by increasing the hydrogen supplement rate. The maximum flame temperature is shown at the $\phi$= 1.0, and increasing the initial pressure and hydrogen supplement rate, it increases. The concentration of NO reveals the highest value at the $\phi$= 0.9, and it increases by increasing the initial pressure and hydrogen supplement rate. It is also found that the limit of lean inflammability of methane-hydrogen-air premixture is greatly widened by increasing the hydrogen supplement rate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.3
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• pp.358-370
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• 1997

In the present study, investigations were carried out to obtain data on combustion characteristics of methane gas and hydrogen supplemented methane gas in a constant volume combustion chamber. The main results obtained from the study can be summarized as follows. The maximum combustion pressure increases as the initial pressure and hydrogen supplement rate increase, the total burning time is shorten by lowering the initial pressure and by increasing the hydrogen supplement rate. The maximum flame temperature and NO concentration increase by the initial pressure and hydrogen supplement rate increase. The flame propagation processes in near stoichiometric mixture are propagated with a spherical shape, but in excess rich or lean mixtures are propagated with a elliptical shape. And, they are changed an unstable elliptical shape flame with very regular cells by increasing the hydrogen supplement rate.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.3
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• pp.156-167
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• 1996

The present work is a continuation of our previous study to investigate the effects of parameters such as equivalence ratio, hydrogen supplement rate and initial pressure on combustion characteristics in a disk-shaped constant volume combustion chamber. The main results obtained from the study can be summarized as follows. The flames in near stoichiometric mixture of methane-air are propagated with a spherical shape, but in excess rich or lean mixtures are propagated with a elliptical shape. And, they are changed to an unstable elliptical shape flame with very regular cells by increasing the hydrogen supplement rate. Also, flame is sluggishly propagated at increased initial pressure in combustion chamber. Volume fraction of burned gas and flame radius as the combustion characteristics are increased by increasing the hydrogen supplement rate, especially at the combustion middle period, but then are slowly increased by increasing the initial pressure.

• Journal of Energy Engineering
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• v.13 no.4
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• pp.311-318
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• 2004

In the present study, the combustion characteristics of methane and hydrogen-supplemented methane as alternative fuels for automotive vehicles were investigated at various hydrogen substitution rate, ignition position and ignition methods in a CVCC. The main results obtained from the study can be summarized as follow. In case of center ignition and neat methane-air mixture, the flame propagation processes are propagated with an elliptical shape, but they are changed an instable elliptical shape flame with very regular cells and higher velocity by increasing the hydrogen supplement rate. In case of side, 0.5R ignition and neat methane-air mixture, the flame propagation processes are propagated with an instable elliptical shape flame, but they are changed from an instable elliptical shape to wedge shape flame with very irregular cells and higher velocity by increasing the hydrogen supplement rate. Although the flame propagation shape with ignition position and ignition devices was not differ, the flame area of MSCDI device was a little larger than it of CDI device at the same time.