scholarly journals Laminar burning velocity of ethanol premixed combustion enriched with liquefied petroleum gas (LPG)

Energetika ◽  
2017 ◽  
Vol 63 (1) ◽  
Author(s):  
Muh Nurkoyim Kustanto ◽  
I Nyoman Gede Wardana ◽  
Mega Nur Sasongko ◽  
Lilis Yuliati
Keyword(s):  
Combustion Chamber ◽  
Burning Velocity ◽  
Premixed Combustion ◽  
Combustion Model ◽  
Oh Radicals ◽  
Laminar Burning Velocity ◽  
Liquefied Petroleum Gas ◽  
Pure Ethanol

The laminar burning velocity of ethanol premixed combustion enriched with liquefied petroleum gas (LPG) has been studied experimentally. The  study was conducted in a  cylindrical combustion chamber, and combustion model was spherically expanding flame. The  results showed that the laminar burning velocity of ethanol enriched with 5–10% LPG is higher than that of pure ethanol and that of pure LPG. This is due to the formation of H and OH radicals in the preheating zone, where the reaction occurs to form H2O and release heat. It raises temperature in the preheating zone which contributes to increase in the laminar burning velocity.

CFD Analysis of the Combustion Chamber of a Commercial Aircraft Engine of Medium Thrust Class From a Maintenance Perspective

2017 ◽  
Author(s):  
Stefan Kuntzagk ◽  
Jörn Kraft ◽  
Ina Esemann
Keyword(s):  
Combustion Chamber ◽  
Temperature Profile ◽  
Measurement Errors ◽  
Burning Velocity ◽  
Combustion Model ◽  
Cfd Analysis ◽  
Hexahedral Mesh ◽  
Flow Topology ◽  
Geometrical Features ◽  
Exit Temperature

The combustion chamber of aircraft engines plays an important role in achieving the optimum performance during an engine overhaul. For long decades, it has been common understanding in the MRO business that a well overhauled compressor and turbine are required to get an engine with low SFC and high EGT margin. In recent work at Lufthansa Technik AG, a comprehensive CFD analysis of the combustion chamber showed that, in contrast to this, small geometrical features influence the mixing process in the combustion chamber and can have an effect on the exit temperature profile. This in turn can reduce the accuracy of the EGT measurement significantly and create measurement errors and misinterpretations of the real engine performance. In order to get insight into the flow topology, a very detailed digital model has been created using scans of the hardware available in the shop. Important geometrical features such as the cooling provisions and swirl creating components have been included in a very detailed manner with an efficient hexahedral mesh. The model includes the HPT vanes and the cooling flow extraction from the secondary cold flow. CFD results have been generated using the flow solver Ansys CFX 17.1, which is able to predict all relevant physical effects such as injection of liquid fuel, evaporation, and combustion of Jet A1 fuel using the Burning-Velocity combustion model. The flow in the combustion chamber shows large natural fluctuations. Subsequently, for each case a transient calculation has been carried out in order to allow an evaluation of the time-averaged flow field. Different geometrical features are investigated to predict the effect of geometry deviations on the exit temperature profile, e.g. the shape and size of the dilution holes. Finally along the example of two CFM56 engines it will be shown how the data obtained by the detailed CFD model is used to optimize work-scoping and maintenance procedures. On the two cases put forward the combination of extended test-cell instrumentation and detailed modeling enabled not only the identification but also the rectification of combustion chamber deviations. This in turn minimized the necessary work, whereas in the past combustion chamber issues often went unnoticed and consequently resulted in extensive additional work.

The Effects of Turbulent Burning Velocity Models in a Swirl-Stabilized Lean Premixed Combustor

2018 ◽  
Vol 35 (4) ◽  
pp. 365-372
Author(s):  
Jong-Chan Kim ◽  
Won-Chul Jung ◽  
Ji-Seok Hong ◽  
Hong-Gye Sung
Keyword(s):  
Burning Velocity ◽  
Premixed Combustion ◽  
Dynamic Mode Decomposition ◽  
Combustion Model ◽  
Dynamic Mode ◽  
Turbulent Premixed Combustion ◽  
Velocity Models ◽  
Flame Structures ◽  
Turbulent Burning Velocity ◽  
Turbulent Premixed

Abstract The effects of turbulent burning velocities in a turbulent premixed combustion simulation with a G-equation are investigated using the 3D LES technique. Two turbulent burning velocity models – Kobayashi model, which takes into account the burning velocity pressure effect, and the Pitsch model, which considers the flame regions on the premixed flame structure – are implemented. An LM6000 combustor is employed to validate the turbulent premixed combustion model. The results show that the flame structures in front of the injector have different shapes in each model because of the different turbulent burning velocities. These different flame structures induce changes in the entire combustor flow field, including in the recirculation zone. The dynamic mode decomposition (DMD) method and linear acoustic analysis provide the dominant acoustic mode.

Development of a Simulation Code for Hydrogen Fuelled SI Engines

2006 ◽  
Author(s):  
Sebastian Verhelst ◽  
Roger Sierens ◽  
Stefaan Verstraeten
Keyword(s):  
Alternative Energy ◽  
Equivalence Ratio ◽  
Internal Combustion Engines ◽  
Burning Velocity ◽  
Combustion Model ◽  
Laminar Burning Velocity ◽  
Velocity Correlation ◽  
Model Framework ◽  
Economic Point ◽  
Velocity Models

Hydrogen is an attractive alternative energy carrier, which could make harmful emissions, global warming and the insecurity concerning oil supply a thing of the past. Hydrogen internal combustion engines can be introduced relatively easily, from a technological as well as from an economic point of view. This paper discusses the development of a model for the combustion of hydrogen in spark ignition engines, which has lead to a simulation program that can assist the optimization of these engines. The importance of a laminar burning velocity correlation taking stretch and instability effects into account is shown. The effects are particularly strong for the highly diffusive hydrogen molecule. In this paper, a laminar burning velocity correlation published previously by two of the authors is combined with a number of turbulent burning velocity models in a quasi-dimensional two-zone combustion model framework. After calibration of the combustion model for a reference condition, simulation results are compared with experimental cylinder pressure data recorded on a single cylinder hydrogen engine. Correspondence between simulation and measurement is shown for varying equivalence ratio, ignition timing and compression ratio. All models performed well for varying ignition timings and compression ratios; the real test proved to be the ability of the models to predict the effects of a varying equivalence ratio, this lead to a clear distinction in the models.

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.

scholarly journals Role of small addition of liquefied petroleum gas (LPG) on laminar burning velocity of hydrous ethanol

2019 ◽  
Vol 3 (8 (99)) ◽  
pp. 56-62
Author(s):  
Muh Nurkoyim Kustanto ◽  
Mega Nur Sasongko ◽  
I Nyoman Gede Wardana ◽  
Lilis Yuliati
Keyword(s):  
Burning Velocity ◽  
Small Addition ◽  
Laminar Burning Velocity ◽  
Liquefied Petroleum Gas ◽  
Hydrous Ethanol

scholarly journals Turbulent burning velocity in combustion chamber of SI engine fueled with compressed biogas

2015 ◽  
Vol 37 (3) ◽  
pp. 205-216
Author(s):  
Bui Van Ga ◽  
Nguyen Van Dong ◽  
Bui Van Hung
Keyword(s):  
Combustion Chamber ◽  
Burning Velocity ◽  
Combustion Process ◽  
Chemical Properties ◽  
Spark Ignition Engines ◽  
Laminar Burning Velocity ◽  
Physico Chemical ◽  
Combustion Simulation ◽  
Velocity Coefficient ◽  
Turbulent Burning Velocity

Turbulent burning velocity is the most important parameter in analyzing pre-mixed combustion simulation of spark ignition engines. It depends on the laminar burning velocity and turbulence intensity in the combustion chamber. The first term can be predicted if one knows fuel composition, physico chemical properties of the fluid. The second term strongly depends on the geometry of the combustion chamber and fluid movement during the combustion process. One cannot suggest a general expression for different cases of engine. Thus, for accuracy modeling, one should determine turbulent burning velocity in the combustion chamber of each case of engine individually. In this study, the turbulent burning velocity is defined by a linear function of laminar burning velocity in which the proportional constant is defined as the turbulent burning velocity coefficient. This coefficient was obtained by analyzing the numerical simulation results and experimental data and this is applied to a concrete case of a Honda Wave motorcycle engine combustion chamber that fueled with compressed biogas. The results showed that the turbulent burning velocity coefficient in this case is around 1.3 when the average engine revolutions is in the range of 3000 rpm to 6000 rpm with biogas containing 80% Methane. We can then predict the effects of different parameters on the performance of the engine fueled with compressed biogas by simulation.

A quasi-dimensional combustion model for spark ignition engines fueled with gasoline–methanol blends

2017 ◽  
Vol 232 (1) ◽  
pp. 57-74 ◽  
Author(s):  
Duc-Khanh Nguyen ◽  
Louis Sileghem ◽  
Sebastian Verhelst
Keyword(s):  
Ignition Delay ◽  
Burning Velocity ◽  
Measurement Data ◽  
Lewis Number ◽  
Combustion Model ◽  
Laminar Burning Velocity ◽  
Velocity Correlation ◽  
Flame Kernel ◽  
Initial Flame ◽  
Better Than

The current work provides a quasi-dimensional model for the combustion of methanol–gasoline blends. New correlations for the laminar burning velocity of gasoline and methanol are developed and used together with a mixing rule to calculate the laminar burning velocity of the blends. Several factors (such as the laminar burning velocity, initial flame kernel, residual gas fraction, turbulence, etc.) have been investigated and the sensitivity of these factors and the used sub-models on the predictive performance was assessed. The simulation results were compared with measurement data from two engines on different gasoline–methanol blends. The results show the importance of the laminar burning velocity correlation, the method of initializing combustion and the turbulent burning velocity model. The newly developed laminar burning velocity correlation of gasoline performed equally or better than the existing correlations and the newly developed correlation of methanol outperformed the other correlations. The initial flame kernel size had a strong influence on the ignition delay. Changing the initial flame kernel to reproduce the same ignition delay was very effective to improve the simulations. Several turbulent combustion models were tested with the newly developed laminar burning velocity correlations and optimized ignition delay. In conclusion, the model of Bradley reproduced the trend going from gasoline to methanol much better than others due to the inclusion of the Lewis number.

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.

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