scholarly journals The Effect of Working Fluids on Premixed Hydrogen Combustion in a Constant Volume Combustion Chamber

2019 ◽  
Author(s):  
Mohammadrasool Morovatiyan ◽  
Martia Shahsavan ◽  
Jonathan Aguilar ◽  
John Hunter Mack
Keyword(s):  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Burning Velocity ◽  
Constant Volume ◽  
Partial Substitution ◽  
Partial Replacement ◽  
Working Fluid ◽  
Laminar Burning Velocity ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber

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.

Effect of Argon Concentration on Laminar Burning Velocity and Flame Speed of Hydrogen Mixtures in a Constant Volume Combustion Chamber

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Mohammadrasool Morovatiyan ◽  
Martia Shahsavan ◽  
Jonathan Aguilar ◽  
J. Hunter Mack
Keyword(s):  
Combustion Chamber ◽  
Burning Velocity ◽  
Internal Combustion ◽  
Hydrogen Combustion ◽  
Flame Speed ◽  
Constant Volume ◽  
Working Fluid ◽  
Laminar Burning Velocity ◽  
Efficient Energy ◽  
Constant Volume Combustion Chamber

Abstract Hydrogen combustion, coupled with the use of argon as a working fluid, is a promising approach to delivering clean and efficient energy from internal combustion (IC) engines. The use of hydrogen-oxygen-argon (H2/O2/Ar) mixtures in combustion aids in mitigating harmful environmental pollutants and enables a highly efficient energy conversion process. The use of argon as a working fluid decreases the NOx emissions and increases the thermal efficiency of internal combustion engines due to the high specific heat ratio of noble gases. In this study, premixed hydrogen combustion 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 (LBV), flame speed, flame morphology, and instability. The experimental approach uses an optically accessible constant volume combustion chamber (CVCC) with central ignition; the spherical flame development was studied using a high-speed Z-type Schlieren visualization system. Moreover, a numerical model was developed to convert the experimental dynamic pressure rise data to laminar burning velocity. Coupling the model to a chemical equilibrium code aids in determining the burned gas properties. Additionally, an image processing technique has been suggested to compute the flame propagation speed. The experimental and numerical investigations indicate that increasing the concentration of argon as the working fluid in the mixture increases the laminar burning velocity and flame speed while extending the lean flammability limit.

scholarly journals 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

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.

scholarly journals The Influence of Mixedness on Ignition for Hydrogen Direct Injection in a Constant Volume Combustion Chamber

2018 ◽  
Author(s):  
Martia Shahsavan ◽  
Mohammadrasool Morovatiyan ◽  
John Hunter Mack
Keyword(s):  
Combustion Chamber ◽  
Ignition Delay ◽  
Gas Turbines ◽  
Flame Temperature ◽  
Constant Volume ◽  
Working Fluid ◽  
Scalar Dissipation ◽  
Mixing Rate ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber

The ignition behavior of the fuel in non-premixed turbulent combustion applications such as diesel engines and gas turbines is dependent on the mixing rate of the injected fuel and the working fluid. In this study, three-dimensional modeling of hydrogen injection into a constant volume combustion chamber (CVCC) is used to investigate the correlation between the mixing rate and important parameters of non-premixed combustion, such as ignition delay. Mixedness is quantified using mean spatial variation, which reflects the homogeneity of the mixture, and mean scalar dissipation, which represents the local gradients of the scalar. The case studies include nitrogen and argon as working fluids; injection velocities and nozzle diameters are varied for comparison. For consistency, the injected mass is kept constant and the injection duration is adjusted accordingly. The results indicate that a strong correlation exists between ignition delay and the defined mixedness parameters. The cases with higher mixedness values lead to a shorter ignition delay and a higher maximum flame temperature. Changing the working fluid and injection parameters can effectively modify the mixedness, and consequently affect the ignition onset and flame properties.

A study of heat flux in a constant-volume combustion chamber

2003 ◽  
Vol 217 (9) ◽  
pp. 825-832 ◽  
Author(s):  
Chi-Woo Lee ◽  
Chi-Won Kim ◽  
Si-Pom Kim
Keyword(s):  
Heat Flux ◽  
Combustion Chamber ◽  
High Performance ◽  
Internal Combustion Engines ◽  
Constant Volume ◽  
Cylinder Wall ◽  
Combustion Engines ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber ◽  
Instantaneous Temperature

In the production of internal combustion engines, there has been a move towards the development of high-performance engines with fuel economy, lighter weights and smaller sizes. These trends help to answer problems related to thermal load and abnormal combustion, etc., in these engines. In order to clarify these problems, a thin film-type probe for instantaneous measurement of surface temperatures has been suggested. A method for manufacturing such a probe was established in this study. The instantaneous surface temperature of a constant-volume combustion chamber was measured by this probe, and heat flux was calculated and analysed with a Fourier series. For a thorough understanding of the characteristics of combustion, the authors measured the wall temperature of the combustion chamber and computed heat flux through a cylinder wall while varying the protrusion height of the probe. To achieve the above goals, an instantaneous temperature probe was developed, thereby making possible the analysis of the instantaneous temperature of the wall surface and unsteady heat flux in the constant-volume combustion chamber.

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.

Comparison of Ethanol and Butanol as Additives in Soybean Biodiesel Using a Constant Volume Combustion Chamber

2011 ◽  
Vol 25 (5) ◽  
pp. 2426-2426 ◽  
Author(s):  
Haifeng Liu ◽  
Chia-fon F. Lee ◽  
Ming Huo ◽  
Mingfa Yao
Keyword(s):  
Combustion Chamber ◽  
Constant Volume ◽  
Soybean Biodiesel ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber
Sign in / Sign up

Export Citation Format

Share Document