Study of Hydrogen-Air Flame Stability with Different Initial Pressure

2012 ◽  
Vol 232 ◽  
pp. 784-787
Author(s):  
Xing Hua Liu ◽  
Hong Liang ◽  
Zhi Qiang Fan ◽  
Dao Jing Wang

Hydrogen-air flame stability with different initial pressures is studied in a constant volume combustion cell. The schlieren flame images and the pressure curves are obtained under various initial pressures, equivalence ratios and initial temperatures. The results show that the time of the laminar flame stage is decreasing with the increasing initial pressure. The main reason of the rapid increasing pressure is whether the squish flame appears. The squish flame stage does not occur when the value of the initial pressure is very low. At this time, the varibility of the pressure is very low. The pressure oscillation occurs when the squish flame or the main flame transmits to the under wall surface. Meanwhile, under the different initial conditions, the time of the mixture combustion process stages is often different, and the flame stability is different. At the same time, the flame crtical radius is decreasing when the initial pressure is increasing.

2012 ◽  
Vol 468-471 ◽  
pp. 2993-2997
Author(s):  
Xiao Juan Liang ◽  
Xi Qin Li

Polycyclic aromatic hydrocarbons are harmful to human body and environment. In order to know the formatting rules of benzene and polycyclic aromatic hydrocarbons in gasoline combustion process, a series of tests are done in a constant volume combustion bomb. The emissions of benzene and polycyclic aromatic hydrocarbons are measured by a gas chromatography-mass spectrometry analyzer. The test results show that the benzene in combustion products comes from the incomplete combustion fuel. The free radicals out of cracking fuel may also become benzene in combustion process. Adding ethanol in fuels does not necessarily increase the emission of benzene. Formation of polycyclic aromatic hydrocarbons varies with temperature.


Author(s):  
Mark A. Fabbroni ◽  
Stewart Xu Cheng ◽  
Vito Abate ◽  
James S. Wallace

Research investigating direct injection natural gas (DING) diesel engines shows many attractions in engine performance including higher thermal efficiency and higher power output as well as significant improvement of exhaust emissions. However, ignition of injected natural gas is difficult and requires some form of ignition assist, such as a diesel pilot or a glow plug. This paper introduces the experimental apparatus used for compression ignition engine studies in the Engine Research and Development Laboratory (ERDL) at University of Toronto. The apparatus consists of an optically accessible constant volume combustion bomb coupled to a single-cylinder Cooperative Fuel Research (CFR) engine through its spark plug port. The engine provides rapid compression to create realistic engine conditions in the combustion bomb and also scavenges the combustion products. During the engine compression process, the piston pushes the air from the engine cylinder to the constant volume combustion bomb, generating high-pressure, high-temperature initial conditions and a strong swirling air flow in the constant volume combustion bomb. Experiments were conducted to measure temperatures and pressures in the constant volume combustion bomb for a range of initial conditions. The experiments were complemented by numerically modeling the whole domain of the CFR engine cylinder, the constant volume combustion bomb, and the port connecting them using a modified KIVA-3V code. The code computes spatially and temporally resolved pressure, temperature and swirl intensity in the constant volume combustion bomb during the compression process. The experimental and the numerical results are in satisfactory agreement and provide validation of the initial conditions in the constant volume combustion bomb for subsequent studies of injection and ignition.


1952 ◽  
Vol 19 (1) ◽  
pp. 72-76
Author(s):  
A. S. Campbell

Abstract By combining the results of an elementary thermodynamic analysis of the temperature distribution in the burned gases of a constant-volume bomb with an examination of the velocity relations at the flame front, it is possible to relate the “normal burning velocity” to the time rate of production of burned gases. Integration of this equation leads to an estimate of the time required for the combustion process.


2020 ◽  
pp. 146808741989693
Author(s):  
Ankith Ullal ◽  
Youngchul Ra ◽  
Jeffrey D Naber ◽  
William Atkinson ◽  
Satoshi Yamada ◽  
...  

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.


2019 ◽  
Vol 142 (6) ◽  
Author(s):  
Kelsey Fieseler ◽  
Taylor Linker ◽  
Mark Patterson ◽  
Daniel Rem ◽  
Timothy J. Jacobs

Abstract Two equations are developed to estimate laminar flame speed and ignition delay for different alkane mixtures at a range of engine-relevant conditions. Fuel mixtures of methane, ethane, propane, butane, and pentane were selected by analyzing the natural gas composition in a natural gas pipeline located in the Midwestern United States. The laminar flame speed and ignition delay were calculated for each mixture at each set of conditions using Cantera, a chemical kinetics solver. The range of initial conditions for laminar flame speed includes temperatures from 300 to 700 K, pressures from 1 to 40 bar, equivalence ratios from 0.4 to 1.2, and residual fractions from 0% to 20%. These data were then fit to a non-linear regression. The range of initial conditions for the ignition delay equation includes temperatures from 1100 to 2000 K, pressures from 1 to 40 bar, equivalence ratios from 0.4 to 1.15, and residual fractions from 0% to 20%. These data were fit to a previously developed equation. Sensitivity studies were conducted on each equation to quantify the impact of the independent variables on the target variable. This showed that, for laminar flame speed, the initial pressure, temperature, and equivalence ratio had the largest impact, with fuel composition having a lesser impact. For ignition delay, the temperature and pressure were shown to have the largest impact. There is a room for improvement, namely, increasing the fuel mixture variability and range of initial conditions, and developing a better fit to the data.


2018 ◽  
Vol 145 ◽  
pp. 187-192 ◽  
Author(s):  
Shubhra Kanti Das ◽  
Hyun Jo ◽  
Kyung Hoon Jwa ◽  
Ocktaeck Lim ◽  
Youngmin Woo

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