Comparison of Representative Interactive Flamelet and Detailed Chemistry Based Combustion Models for Internal Combustion Engines

2014 ◽  
Author(s):  
M. Wang ◽  
M. Raju ◽  
E. Pomraning ◽  
P. Kundu ◽  
Y. Pei ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engines ◽  
Mixture Fraction ◽  
Spray Cooling ◽  
Combustion Model ◽  
Combustion Engines ◽  
Detailed Chemistry ◽  
Combustion Models ◽  
Computational Fluid Dynamics Cfd ◽  
Lift Off

Representative Interactive Flamelet (RIF) and Detailed Chemistry based combustion models are two commonly used combustion models for non-premixed diesel engine simulations. RIF performs transient chemistry calculations on a one-dimensional grid based on the mixture fraction coordinate. Hence, the chemistry calculations are essentially decoupled from the computational fluid dynamics (CFD) grid. The detailed chemistry model, on the other hand, solves transient chemistry in the 3D CFD domain. An efficient parallelization strategy is used for the computation of the multiple flamelets RIF model. The multiple flamelets RIF and detailed chemistry combustion models are applied for modeling a constant volume spray combustion case and a diesel engine case, with a view to compare the differences between the two models. Results for ignition delay, flame lift-off length, cylinder pressure, and emissions are compared with experimental data. The effect of number of flamelets is evaluated. Finally, the effect of spray cooling is investigated based on the results from the RIF model and the detailed chemistry based combustion model.

DIESEL ENGINE OPERATION IN USE OF FUEL WITH ADDITIVES

2018 ◽  
pp. 18-24
Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Combustion Engines ◽  
Engine Operation ◽  
Factors Affecting ◽  
Operating Modes ◽  
Positive Effects

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.

Comparison of Temperature Fields and Emissions Predictions Using Both an FGM Combustion Model, With Detailed Chemistry, and a Simple Eddy Dissipation Combustion Model With Simple Global Chemistry

2017 ◽  
Author(s):  
Pierre Q. Gauthier
Keyword(s):  
Mixture Fraction ◽  
Temperature Fields ◽  
Combustion Model ◽  
Detailed Chemistry ◽  
Combustion Modeling ◽  
Flamelet Generated Manifold ◽  
Wide Range ◽  
Turbulence Effects ◽  
Air Chemistry ◽  
Dissipation Model

The detailed modeling of the turbulence-chemistry interactions occurring in industrial flames has always been the leading challenge in combustion Computational Fluid Dynamics (CFD). The wide range of flame types found in Industrial Gas Turbine Combustion systems has exacerbated these difficulties greatly, since the combustion modeling approach must be able to predict the flames behavior from regions of fast chemistry, where turbulence has no significant impact on the reactions, to regions where turbulence effects play a significant role within the flame. One of these combustion models, that is being used more and more in industry today, is the Flamelet Generated Manifold (FGM) model, in which the flame properties are parametrized and tabulated based on mixture fraction and flame progress variables. This paper compares the results obtained using an FGM model, with a GRI-3.0 methane-air chemistry mechanism, against the more traditional Industrial work-horse, Finite-Rate Eddy Dissipation Model (FREDM), with a global 2-step Westbrook and Dryer methane-air mechanism. Both models were used to predict the temperature distributions, as well as emissions (NOx and CO) for a conventional, non-premixed, Industrial RB211 combustion system. The object of this work is to: (i) identify any significant differences in the predictive capabilities of each model and (ii) discuss the strengths and weakness of both approaches.

scholarly journals THE COMBUSTION ENGINE INTAKE MANIFOLD CFD MODELING DEPENDING ON THE AIRBOX CONFIGURATION

2021 ◽  
Vol 2021 (6) ◽  
pp. 5421-5425
Author(s):  
MICHAL RICHTAR ◽  
◽  
PETRA MUCKOVA ◽  
JAN FAMFULIK ◽  
JAKUB SMIRAUS ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Stationary Flow ◽  
Cfd Modeling ◽  
Intake Manifold ◽  
Combustion Engines ◽  
Computational Fluid Dynamics Cfd

The aim of the article is to present the possibilities of application of computational fluid dynamics (CFD) to modelling of air flow in combustion engine intake manifold depending on airbox configuration. The non-stationary flow occurs in internal combustion engines. This is a specific type of flow characterized by the fact that the variables depend not only on the position but also on the time. The intake manifold dimension and geometry strongly effects intake air amount. The basic target goal is to investigate how the intake trumpet position in the airbox impacts the filling of the combustion chamber. Furthermore, the effect of different distances between the trumpet neck and the airbox wall in this paper will be compared.

scholarly journals Energetic Analysis of the Aircraft Diesel Engine

2019 ◽  
Vol 252 ◽  
pp. 05012
Author(s):  
Łukasz Grabowski ◽  
Konrad Pietrykowski ◽  
Paweł Karpiński
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Energy Balance ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Energy Losses ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Engine Model ◽  
Energetic Analysis

The analysis of the distribution of thermal energy generated during the combustion process in internal combustion engines and the estimation of individual losses are important regarding performance and efficiency. The article analyses the energy balance of the designed two-stroke opposed piston diesel engines with offset, i.e. the angle by which the crankshaft at the side of exhaust ports is ahead of the crankshaft at the side of intake ports. Based on the developed zero-dimensional engine model, a series of simulations were performed in steady-state conditions using the AVL BOOST software. The values of individual energy losses, including cooling losses, exhaust gas losses, friction losses were obtained. The influence of decreasing and increasing the offset on the performance of the tested engine was analysed.

Large Eddy Simulation of High Reynolds Number Nonreacting and Reacting JP-8 Sprays in a Constant Pressure Flow Vessel With a Detailed Chemistry Approach

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Luis Bravo ◽  
Sameera Wijeyakulasuriya ◽  
Eric Pomraning ◽  
Peter K. Senecal ◽  
Chol-Bum Kweon
Keyword(s):  
Large Eddy Simulation ◽  
Internal Combustion Engines ◽  
Constant Pressure ◽  
Engine Performance ◽  
Spray Combustion ◽  
Pressure Flow ◽  
Detailed Chemistry ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Lift Off

In military propulsion applications, the characterization of internal combustion engines operating with jet fuel is vital to understand engine performance, combustion phasing, and emissions when JP-8 is fully substituted for diesel fuel. In this work, high-resolution large eddy simulation (LES) simulations have been performed in-order to provide a comprehensive analysis of the detailed mixture formation process in engine sprays for nozzle configurations of interest to the Army. The first phase examines the behavior of a nonreacting evaporating spray, and demonstrates the accuracy in predicting liquid and vapor transient penetration profiles using a multirealization statistical grid-converged approach. The study was conducted using a suite of single-orifice injectors ranging from 40 to 147 μm at a rail pressure of 1000 bar and chamber conditions at 900 K and 60 bar. The next phase models the nonpremixed combustion behavior of reacting sprays and investigates the submodel ability to predict auto-ignition and lift-off length (LOL) dynamics. The model is constructed using a Kelvin Helmholtz–Rayleigh Taylor (KH–RT) spray atomization framework coupled to an LES approach. The liquid physical properties are defined using a JP-8 mixture containing 80% n-decane and 20% trimethylbenzene (TMB), while the gas phase utilizes the Aachen kinetic mechanism (Hummer, et al., 2007, “Experimental and Kinetic Modeling Study of Combustion of JP-8, Its Surrogates, and Reference Components in Laminar Non Premixed Flows,” Proc. Combust. Inst., 31, pp. 393–400 and Honnet, et al., 2009, “A Surrogate Fuel for Kerosene,” Proc. Combust. Inst., 32, pp. 485–492) and a detailed chemistry combustion approach. The results are in good agreement with the spray combustion measurements from the Army Research Laboratory (ARL), constant pressure flow (CPF) facility, and provide a robust computational framework for further JP-8 studies of spray combustion.

Experimental Studies on the Performance of C.I Engine with Fish Oil Methyl Ester as Fuel for Various Blends of Diesel and LPG

2015 ◽  
Vol 787 ◽  
pp. 687-691
Author(s):  
Tarigonda Hari Prasad ◽  
R. Meenakshi Reddy ◽  
P. Mallikarjuna Rao
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Research Work ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Inlet Manifold

Fossil fuels are exhausting quickly because of incremental utilization rate due to increase population and essential comforts on par with civilization. In this connection, the conventional fuels especially petrol and diesel for internal combustion engines, are getting exhausted at an alarming rate. In order to plan for survival of technology in future it is necessary to plan for alternate fuels. Further, these fossil fuels cause serious environmental problems as they release toxic gases into the atmosphere at high temperatures and concentrations. The predicted global energy consumption is increasing at faster rate. In view of this and many other related issues, these fuels will have to be replaced completely or partially by less harmful alternative, eco-friendly and renewable source fuels for the internal combustion engines. Hence, throughout the world, lot of research work is in progress pertaining to suitability and feasibility of alternative fuels. Biodiesel is one of the promising sources of energy to mitigate both the serious problems of the society viz., depletion of fossil fuels and environmental pollution. In the present work, experiments are carried out on a Single cylinder diesel engine which is commonly used in agricultural sector. Experiments are conducted by fuelling the diesel engine with bio-diesel with LPG through inlet manifold. The engine is properly modified to operate under dual fuel operation using LPG through inlet manifold as fuel along FME as ignition source. The brake thermal efficiency of FME with LPG (2LPM) blend is increased at an average of 5% when compared to the pure diesel fuel. HC emissions of FME with LPG (2LPM) blend are reduced by about at an average of 21% when compared to the pure diesel fuel. CO emissions of FME with LPG (2LPM) blends are reduced at an average of 33.6% when compared to the pure diesel fuel. NOx emissions of FME with LPG (2LPM) blend are reduced at an average of 4.4% when compared to the pure diesel fuel. Smoke opacity of FME with LPG (2LPM) blend is reduced at an average of 10% when compared to the pure diesel fuel.

scholarly journals A Numerical Exploration of Engine Combustion Using Toluene Reference Fuel and Hydrogen Mixtures

2021 ◽  
Vol 312 ◽  
pp. 07003
Author(s):  
Alessio Barbato ◽  
Valentina Pessina ◽  
Massimo Borghi
Keyword(s):  
Internal Combustion Engines ◽  
Laminar Flame ◽  
Pure Hydrogen ◽  
Combustion Engines ◽  
Feeding System ◽  
Numerical Exploration ◽  
Wide Range ◽  
Engine Combustion ◽  
Hydrogen Mixtures ◽  
Computational Fluid Dynamics Cfd

Hydrogen-fueled internal combustion engines (H2ICEs) are capable of operating over a wide range of equivalence ratios: from ultra-lean mode to stoichiometric conditions. However, they provide maximum thermal efficiency and minimum NOx emissions if operated lean. Although NOx is produced, H2ICEs generate little or no CO, CO2, SO2, HC, or PM emissions. The main limitation to pure hydrogen fueling is power density. To overcome such an issue, mixtures of gasoline and hydrogen can be exploited, with small modifications to the engine feeding system. Due to the peculiar characteristics of hydrogen (in terms of thermophysical properties, molecular weight and propagating flame characteristics) care must be adopted when trying to address combustion using computational fluid dynamics (CFD) tools. In this work, we simulate the combustion of mixtures of toluene reference fuel (TRF) and hydrogen under largely different ratios. To simplify the problem, liquid and gaseous injections are neglected, and a premixed mixture at the inlet of the CFD domain is imposed. Due to the different laminar flame speeds of the mixture components, mass-fraction weighted in-house correlations based on chemical kinetics simulations are adopted. Outcomes are compared with those obtained using standard correlations and mixing rules available in most commercial CFD packages.

scholarly journals Numerical simulation of n-dodecane spray combustion based on OpenFOAM

2021 ◽  
Vol 39 (3) ◽  
pp. 539-548
Author(s):  
Wengang Li ◽  
Yinli Xiao ◽  
Yipin Lu ◽  
Zhibo Cao ◽  
Juan Wu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Fuel Injection ◽  
Mixture Fraction ◽  
Spray Combustion ◽  
Combustion Model ◽  
Temperature Reaction ◽  
Penetration Length ◽  
Chemical Reaction Kinetics ◽  
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For the purpose of providing the scientific insights to combustion characteristics of spray jet, numerical calculations of reacting and non-reacting spray cases are performed for ECN (engine combustion network) Spray A (n-dodecane spray combustion) which coupled finite chemistry combustion model PaSR and detailed chemical reaction kinetics based on OpenFOAM. The applicability and accuracy of the spray model is verified in the non-reacting spray case, and it is found that the predicted spray characteristics such as the penetration length of liquid and vapor and the mixture fraction are in good agreement with the test results. The two processes of low-temperature reaction and high-temperature ignition experienced by n-dodecane spray ignition are analyzed in reacting spray case, and it is found that the low-temperature reaction continues to exothermic before high-temperature ignition, and continues to proceed stably after high-temperature ignition, which promotes high-temperature ignition and flame stability. Finally, the effects of different fuel injection pressures on ignition delay time and flame lift-off length are studied.

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