Effect of hydrogen enrichment of compressed natural gas on combustible limit and flame kernel evolution in a constant volume combustion chamber using laser ignition

Pre-ignition in internal combustion engines is an abnormal combustion phenomenon which often results in structural damage to the engine. It occurs when an ignition event takes place in the combustion chamber before the designed ignition time. In this work, a numerical study was done to investigate the pre-ignition with potential application to natural gas marine engines. This was done by simulating experiments of lube oil–induced ignition and subsequent combustion in a constant volume combustion chamber using an in-house version of the KIVA4-CFD code. Initial conditions of the chamber gases are obtained from the pre-burn process of a known composition of C2H2/oxidizer mixture. Natural gas was injected from a single-hole injector at an injection temperature and pressure of 300 K and 105 Pa, respectively. A rotating fan was modeled, as is in the experimental setup. Oil droplet of known size and velocity is injected into the constant volume combustion chamber. For accurate prediction of oil droplet ignition, the computational cells that contain the droplets are to be refined. Combustion calculations are then carried out on the refined grid. Ignition delay times of both lube oil and methane/air mixtures were calculated. Parametric studies were also conducted by varying droplet conditions, and their results are also presented.

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Numerical Study on Direct Injection of Hydrogen-Methane Blends into a Constant Volume Combustion Chamber

10.31224/osf.io/ebvah ◽

2019 ◽

Author(s):

Mohammadrasool Morovatiyan ◽

Martia Shahsavan ◽

John Hunter Mack

Keyword(s):

Natural Gas ◽

Combustion Chamber ◽

Volume Fraction ◽

Numerical Study ◽

Computational Study ◽

Constant Volume ◽

Chamber Pressure ◽

Compression Ignition ◽

Constant Volume Combustion ◽

Constant Volume Combustion Chamber

Natural gas is not commonly used in compression ignition cycles due to difficulty in achieving autoignition conditions. The addition of hydrogen to natural gas can help overcome this issue considering hydrogen’s flammability range and ability to autoignite. In this computational study, the turbulent injection of hydrogen-methane mixtures with varied composition of the gaseous fuels into a constant volume combustion chamber has been modeled. All conditions including injection pressure, initial chamber temperature, and initial chamber pressure are kept constant; the jet properties and combustion characteristics were then investigated. The results indicate that adding hydrogen to methane drastically shortens the ignition delay, enables the system to run at a lower initial temperature, and provides appropriate conditions for the compression ignition of the gaseous fuel. Increasing the volume fraction of hydrogen in the mixture strongly affects the spray tip penetration length and cone angle, while altering the mixing rate of the injected fuel with air. The mixtures with higher hydrogen volume fractions penetrate more during the early stages of injection. However, the higher momentum of the mixtures with more methane compensates for this effect when the jet disperses significantly in the chamber.

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COMBUSTION CHARACTERIZATION OF LASER IGNITION OF METHANE AIR MIXTURE IN A CONSTANT VOLUME COMBUSTION CHAMBER

10.1615/ihmtc-2017.1660 ◽

2018 ◽

Author(s):

Sanket Mulye ◽

Chidanand Koshti ◽

Milankumar Nandgaonkar

Keyword(s):

Combustion Chamber ◽

Constant Volume ◽

Laser Ignition ◽

Constant Volume Combustion ◽

Constant Volume Combustion Chamber

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Natural Gas Partially Stratified Lean Combustion: Analysis of the Enhancing Mechanisms into a Constant Volume Combustion Chamber

Fuel ◽

10.1016/j.fuel.2017.09.100 ◽

2018 ◽

Vol 211 ◽

pp. 737-753 ◽

Cited By ~ 6

Author(s):

L. Bartolucci ◽

S. Cordiner ◽

V. Mulone ◽

V. Rocco

Keyword(s):

Natural Gas ◽

Combustion Chamber ◽

Constant Volume ◽

Combustion Analysis ◽

Lean Combustion ◽

Constant Volume Combustion ◽

Constant Volume Combustion Chamber

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Analysis of flame kernel development with Schlieren and laser deflection in a constant volume combustion chamber

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/095440702760178604 ◽

2002 ◽

Vol 216 (7) ◽

pp. 581-590 ◽

Cited By ~ 6

Author(s):

J Song ◽

M Sunwoo

Keyword(s):

Combustion Chamber ◽

Dwell Time ◽

Constant Volume ◽

Flame Velocity ◽

Ignition Energy ◽

Schlieren Method ◽

Kernel Development ◽

Flame Kernel ◽

Constant Volume Combustion ◽

Constant Volume Combustion Chamber

The purpose of this study is to investigate the relation between ignition systems (or energy) and flame kernel development. In this research, three different kinds of ignition systems and several different kinds of spark plug electrodes are designed and manufactured. The flame propagation velocity in a constant volume combustion chamber is measured by both a laser deflection method using an He-Ne laser and a Schlieren method using a high speed digital camera. In order to control the ignition energy, the dwell time is varied by a spark time controller. The results indicate that, when the ignition energy is increased by extending the dwell time, flame kernel growth accelerates. As the electrode gap width is increased, the breakdown energy is also increased, which stimulates the initial kernel development. The materials, diameter and shape of the electrode affect the discharged energy, the energy transfer efficiency and heat losses and, thus, these also affect the flame kernel development. The average difference in measurement of the flame velocity by the laser deflection method and Schlieren method is only 1.73 per cent. The laser deflection method is found to be preferable because it is more effective and employs simpler means for the analysis of flame kernel development.

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