Transported PDF Modeling of Turbulent Non-Premixed Jet Flames Including Soot Formation

2010 ◽  
Author(s):  
K. Nold ◽  
P. Gerlinger ◽  
R. Eggels ◽  
M. Aigner
Keyword(s):  
Soot Formation ◽  
Jet Flames

Prediction of Soot Formation Trends in Turbulent Kerosene-Air Diffusion Jet Flames With Elevated Operating Pressure

2017 ◽  
Author(s):  
Pravin Nakod ◽  
Saurabh Patwardhan ◽  
Ishan Verma ◽  
Stefano Orsino
Keyword(s):  
Environmental Protection Agency ◽  
Volume Fraction ◽  
Soot Formation ◽  
Mixture Fraction ◽  
Soot Volume Fraction ◽  
Operating Pressure ◽  
Jet Flames ◽  
Emission Standard ◽  
Radial Profiles ◽  
Air Diffusion

Emission standard agencies are coming up with more stringent regulations on soot, given its adverse effect on human health. It is expected that Environmental Protection Agency (EPA) will soon place stricter regulations on allowed levels of the size of soot particles from aircraft jet engines. Since, aircraft engines operate at varying operating pressure, temperature and air-fuel ratios, soot fraction changes from condition to condition. Computation Fluid Dynamics (CFD) simulations are playing a key role in understanding the complex mechanism of soot formation and the factors affecting it. In the present work, soot formation prediction from numerical analyses for turbulent kerosene-air diffusion jet flames at five different operating pressures in the range of 1 atm. to 7 atm. is presented. The geometrical and test conditions are obtained from Young’s thesis [1]. Coupled combustion-soot simulations are performed for all the flames using steady diffusion flamelet model for combustion and Mass-Brookes-Hall 2-equation model for soot with a 2D axisymmetric mesh. Combustion-Soot coupling is required to consider the effect of soot-radiation interaction. Simulation results in the form of axial and radial profiles of temperature, mixture fraction and soot volume fraction are compared with the corresponding experimental measured profiles. The results for temperature and mixture fraction compare well with the experimental profiles. Predicted order of magnitude and the profiles of the soot volume fraction also compare well with the experimental results. The correct trend of increasing the peak soot volume fraction with increasing the operating pressure is also captured.

scholarly journals Numerical Simulation of Soot Formation in Spray Jet Flames

2012 ◽  
Vol 49 (6) ◽  
pp. 467-477 ◽  
Author(s):  
Hiroaki Watanabe ◽  
Ryoichi Kurose ◽  
Yutaka Yano ◽  
Hisao Makino ◽  
Satoru Komori
Keyword(s):  
Numerical Simulation ◽  
Soot Formation ◽  
Jet Flames

scholarly journals Effects of Fuel Molecular Weight on Emissions in a Jet Flame and a Model Gas Turbine Combustor

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Anandkumar Makwana ◽  
Suresh Iyer ◽  
Milton Linevsky ◽  
Robert Santoro ◽  
Thomas Litzinger ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Volume Fraction ◽  
Soot Formation ◽  
Premixed Flames ◽  
Soot Volume Fraction ◽  
Spatial Development ◽  
Gas Turbine Combustor ◽  
Jet Flames ◽  
Jet Flame ◽  
Model Gas Turbine Combustor

The objective of this study is to understand the effects of fuel volatility on soot emissions. This effect is investigated in two experimental configurations: a jet flame and a model gas turbine combustor. The jet flame provides information about the effects of fuel on the spatial development of aromatics and soot in an axisymmetric, co-flow, laminar flame. The data from the model gas turbine combustor illustrate the effect of fuel volatility on net soot production under conditions similar to an actual engine at cruise. Two fuels with different boiling points are investigated: n-heptane/n-dodecane mixture and n-hexadecane/n-dodecane mixture. The jet flames are nonpremixed and rich premixed flames in order to have fuel conditions similar to those in the primary zone of an aircraft engine combustor. The results from the jet flames indicate that the peak soot volume fraction produced in the n-hexadecane fuel is slightly higher as compared to the n-heptane fuel for both nonpremixed and premixed flames. Comparison of aromatics and soot volume fraction in nonpremixed and premixed flames shows significant differences in the spatial development of aromatics and soot along the downstream direction. The results from the model combustor indicate that, within experiment uncertainty, the net soot production is similar in both n-heptane and n-hexadecane fuel mixtures. Finally, we draw conclusions about important processes for soot formation in gas turbine combustor and what can be learned from laboratory-scale flames.

Phenomenological Simulation of Non-Premixed Gas Jet Flames Including Soot Formation and Oxidation

2012 ◽  
Author(s):  
Ehsan Faghani ◽  
Steven N. Rogak
Keyword(s):  
Mass Fraction ◽  
Soot Formation ◽  
Equilibrium Composition ◽  
Gas Jet ◽  
Jet Flames ◽  
Engine Simulation ◽  
Soot Mass ◽  
Wide Range ◽  
Computationally Intensive ◽  
Energy Balances

A phenomenological model (called here “Slice Model”) has been developed to simulate non-premixed gas jet flames including soot formation in the domain. The Slice Model is based on the self-similarity solution of gas jets and forced to satisfy momentum, mass and energy balances in every cross section. The Slice Model can predict the velocity, mass fraction and temperature field of non-reacting and reacting jets over a wide range of changes in the jet parameters. A sub-model for soot formation based on Hiroyasu’ model is applied to predict soot formation in non-premixed flames. Cantera, an open-source chemical kinetics software, is integrated with the Slice Model to predict the temperature distribution (based on equilibrium composition) of reacting jets. The soot formation prediction of the Slice Model is compared with experimental data in the literature. For velocity, soot mass fraction and temperature, agreement with experiment is about as good as it is for the much more computationally intensive RANS CFD simulations. On this basis, the Slice Model is promising as the core of a non-premixed natural gas engine simulation package under development.

Fuel pyrolysis and its effects on soot formation in non-premixed laminar jet flames of methane, propane, and DME

2018 ◽  
Vol 13 (6) ◽  
pp. 56
Author(s):  
Min-Kyu Jeon ◽  
Nam Il Kim
Keyword(s):  
Thermal Effects ◽  
Soot Formation ◽  
Flame Length ◽  
Jet Flames ◽  
Laminar Jet ◽  
Theoretical Predictions ◽  
Temperature Combustion ◽  
Premixed Laminar ◽  
Fuel Pyrolysis ◽  
High Temperature Combustion

High-temperature combustion techniques have recently attracted interest with regard to the improvement of the thermal efficiency of combustion systems. Fuel pyrolysis is an important factor, as it can affect such flame structures at high temperatures. In this study, the pyrolysis of methane, propane, and dimethyl ether (DME) was measured and the results were compared with theoretical predictions. Pyrolyzed fuels were quenched to room temperature before being introduced onto the burner. Thus, the pyrolysis effects on laminar non-premixed jet flames could be distinguished from many other complex thermal effects. It was found that the flame length was not notably extended in spite of the great increase in the volumetric flow rates resulting from the pyrolysis. In contrast, fuel pyrolysis could significantly affect the soot formation process,and the number of smoke points could be sharply reduced depending on the pyrolysis temperature. Distributions of the luminous intensity and scattering intensity levels in the soot region were discussed in terms of the soot temperatures obtained with a two-color method. Although the adiabatic flame temperatures of the pyrolyzed fuels were theoretically increased, the actual soot temperatures could be reduced when the soot particles were excessively formulated, as in the case with propane flames.

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