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

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.

scholarly journals Experimental and Computational Study of n-Heptane Autoignition in a Direct-Injection Constant-Volume Combustion Chamber

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
James C. Allen ◽  
William J. Pitz ◽  
Brian T. Fisher
Keyword(s):  
Combustion Chamber ◽  
Computational Study ◽  
Direct Injection ◽  
Negative Temperature ◽  
Constant Volume ◽  
Chamber Pressure ◽  
Combustion Model ◽  
Significant Finding ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber

The purpose of this study was to characterize experimental n-heptane combustion behavior in a direct-injection constant-volume combustion chamber (DI-CVCC), using chamber pressure to infer ignition delay and heat-release rate. Measurements generally displayed expected trends and indicated entirely premixed combustion with no mixing-controlled phase. A significant finding was the observation of negative temperature coefficient (NTC) behavior. Comparing results with CHEMKIN-PRO simulations, it was found that a homogeneous combustion model was reasonably accurate for ignition delays longer than 5 ms. The combination of NTC behavior and homogeneous fuel-air mixtures suggests that this DI-CVCC can be useful for validation of chemical-kinetic mechanisms.

Numerical investigation of oil droplet combustion using single particle ignition cell model

2020 ◽  
pp. 146808741989693
Author(s):  
Ankith Ullal ◽  
Youngchul Ra ◽  
Jeffrey D Naber ◽  
William Atkinson ◽  
Satoshi Yamada ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Structural Damage ◽  
Internal Combustion Engines ◽  
Initial Conditions ◽  
Numerical Study ◽  
Constant Volume ◽  
Oil Droplet ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber

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.

The flame behaviour of liquefied petroleum gas spray impinging on a flat plate in a constant volume combustion chamber

2005 ◽  
Vol 219 (5) ◽  
pp. 655-663 ◽  
Author(s):  
Kweonha Park
Keyword(s):  
Combustion Chamber ◽  
Ambient Pressure ◽  
Constant Volume ◽  
Chamber Pressure ◽  
Cylinder Wall ◽  
Liquefied Petroleum Gas ◽  
Wide Range ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber ◽  
Ignition Site

Liquefied petroleum gas (LPG) sprays and diffusion flames are investigated in a constant volume combustion chamber having an impingement plate. The spray and flame images are visualized and compared with diesel and gasoline images over a wide range of ambient pressure. The high-speed digital camera is used to take the flame images. The injection pressure is generated by a Haskel air-driven pump, and the initial chamber pressure is adjusted by the amount of pumping air. The LPG spray and flame photographs are compared with those of gasoline and diesel fuel at the same conditions, and then the spray and flame development behaviour is analysed. The spray photographs show that the dispersion characteristics of LPG spray are sensitive to the ambient pressure. In a low initial chamber pressure LPG fuel in the liquid phase evaporates quickly and does not reach down easily to the impinging plate having a hot coil for ignition. That makes the temperature and equivalence ratio low near the ignition coil, thus making ignition diffcult. On the other hand, in a high initial chamber pressure the spray leaving the nozzle gathers around the ignition site after impinging on the plate, which makes an intense flame near the plate. If applied to small-sized direct injection engines that are not able to avoid spray impinging on a cylinder wall, LPG will have faster and cleaner combustion than diesel or gasoline fuels. However, the chamber geometry should be carefully designed to enable a sufficient amount of vaporized fuel to get to the ignition site

Experimental and numerical study of cyclic variations in a Constant Volume Combustion chamber

2016 ◽  
Vol 172 ◽  
pp. 49-61 ◽  
Author(s):  
Laure Labarrere ◽  
Thierry Poinsot ◽  
Antoine Dauptain ◽  
Florent Duchaine ◽  
Marc Bellenoue ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Numerical Study ◽  
Constant Volume ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber ◽  
Cyclic Variations
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