96/00712 Measuring the laminar burning velocity of methane/diluent/air mixtures within a constant-volume combustion bomb in a micro-gravity environment

Premixed combustion of hydrogen was investigated with the purpose of examining the effect of the full or partial substitution of argon for nitrogen in air on laminar burning velocity. Theoretically, this partial replacement decreases the NOx emissions and increases the thermal efficiency of internal combustion engines due to the high specific heat ratio of noble gases. An optically-accessible constant volume combustion chamber (CVCC) with central ignition was used to study flame propagation, flame morphological structure, and instability. The spherical flame development was studied using a high-speed Z-type Schlieren visualization system. Moreover, a numerical model was developed to convert the pressure rise data to laminar burning velocity. Coupling the model to a chemical equilibrium code aids in determining the burned gas properties. The experimental and numerical investigations indicate that increasing the concentration of argon as the working fluid in the mixture can increase the laminar burning velocity and extend the lean flammability limit.

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The uncertainty of laminar burning velocity of premixed H2-air flame induced by the non-uniform initial temperature field inside the constant-volume combustion vessel

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2018.09.037 ◽

2018 ◽

Vol 43 (45) ◽

pp. 21049-21059 ◽

Cited By ~ 4

Author(s):

Zunhua Zhang ◽

Peng Cheng ◽

Jian Tan ◽

Junjie Liang ◽

Yeyuan Li ◽

...

Keyword(s):

Temperature Field ◽

Initial Temperature ◽

Burning Velocity ◽

Constant Volume ◽

Laminar Burning Velocity ◽

Constant Volume Combustion ◽

Combustion Vessel

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A study on the influence of ignition energy on ignition delay time and laminar burning velocity of lean methane/air mixture in a constant volume combustion chamber

Journal of Science and Technology Issue on Information and Communications Technology ◽

10.31130/ud-jst2021-009e ◽

2021 ◽

pp. 1-4

Author(s):

Nguyen Minh Tien Nguyen

Keyword(s):

Combustion Chamber ◽

Ignition Delay ◽

Delay Time ◽

Ignition Delay Time ◽

Burning Velocity ◽

Constant Volume ◽

Laminar Burning Velocity ◽

Ignition Energy ◽

Constant Volume Combustion ◽

Constant Volume Combustion Chamber

This study presents the effect of ignition energy (Eig) on ignition delay time (tdelay) and uncertainty of laminar burning velocity (Su0) measurement of lean methane/air mixture in a constant volume combustion chamber. The mixture at an equivalence ratio of 0.6 is ignited using a pair of electrodes at the 2-mm spark gap. Eig is measured by integrating the product of voltage V(t) and current I(t) signals during a discharge period. The in-chamber pressure profiles are analyzed using the pressure-rise method to obtain tdelay and Su0. Su0 approximates 8.0 cm/s. Furthermore, the increasing Eig could shorten tdelay, leading to a faster combustion process. However, when Eig is greater than a critical value, called minimum reliable ignition energy (MRIE), the additional elevating Eig has the marginal effect on tdelay and Su0. The existence of MRIE supports to optimize the ignition systems and partly explains why extreme-high Eig>> MRIE has less contribution to engine performance.

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