scholarly journals A Model for Computation of Net Local Soot Generation

1982 ◽  
Author(s):  
S. S. Koussa
Keyword(s):  
Experimental Data ◽  
Soot Formation ◽  
Soot Concentration ◽  
Positive Step

A model which is believed to be a positive step towards finding a model appropriate for detailed prediction of soot concentration in practical combustors is presented. The model considers the effect of turbulence on soot formation and destruction without excessive penalty on multidimensional computations. Comparison of the predictions with some experimental data shows that the general trends may be predicted with accuracy acceptable in most practical cases.

Modelling of Soot Formation in Spray Combustors

1983 ◽  
Author(s):  
S. S. Koussa
Keyword(s):  
Experimental Data ◽  
Liquid Phase ◽  
Gas Phase ◽  
Soot Formation ◽  
Soot Concentration ◽  
Practical Application ◽  
Combustion Modelling

A model for the prediction of the distribution of soot concentration in spray combustors is presented. Both gas-phase and liquid-phase soot formation have been considered. The methods have been developed within the constraints on detailed combustion modelling for practical application. Some predictions are assessed by comparison with published experimental data. It is concluded that predictions of the same quality as those of gaseous-fuelled combustors may be obtained neglecting liquid-phase soot formation in case of light fuels.

Simulation of Particle Synthesis by Premixed Laminar Stagnation Flames

2013 ◽  
Vol 1506 ◽  
Author(s):  
Abhijit Modak ◽  
Karthik Puduppakkam ◽  
Chitralkumar Naik ◽  
Ellen Meeks
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Particle Production ◽  
Soot Formation ◽  
Laminar Flame ◽  
Practical Importance ◽  
Batch Reactors ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Premixed Laminar

ABSTRACTA sectional method for determining particle size distributions has been implemented within the particle tracking module included with CHEMKIN-PRO. The module is available for use with many types of reactor models, ranging from 0-D batch reactors to laminar flame simulations. Coupled with the Burner-stabilized Stagnation Flame (BSSF) Model, the sectional model offers a high-fidelity, robust, and efficient computational framework for simulating flame synthesis of particles in a laminar, premixed stagnation flame environment. The CHEMKIN-PRO coupling allows inclusion of detailed gas-phase chemistry that determines key particle-formation precursors, along with physical processes such as nucleation and coagulation of particles. These capabilities are demonstrated for two flame-particle systems of practical importance, viz. nanocrystalline titania synthesis and soot formation. The results are compared with experimental data obtained at the University of Southern California (USC) flame facility. Computed particle size distributions show good agreement with experimental data. Simulations have led to exploration of the parameter space for particle production and particle-size influences.

Application of a Phenomenological Soot Model for Diesel Engine Combustion

2008 ◽  
Author(s):  
Xiaobei Cheng ◽  
Hongling Jv ◽  
Yifeng Wu
Keyword(s):  
Diesel Engine ◽  
Chemical Reactions ◽  
Oxidation Rate ◽  
Soot Formation ◽  
Soot Oxidation ◽  
Soot Concentration ◽  
Engine Operation ◽  
Soot Particles ◽  
Turbulent Eddies ◽  
Soot Model

The application of the improved CFD code for the simulation of combustion and emission formation in a high-speed diesel engine has been presented and discussed. The soot concentration transport equation is found and solved together with all other flow equations. A slip correction factor is introduced into this equation. In turbulent combustion, the soot particles are contained within the turbulent eddies, and burnt up swiftly with the dissipation of these eddies in the soot oxidation zone. However, the chemical reactions always process except the dissipation of turbulent eddies and the intermixing of soot particles and turbulent eddies. The soot oxidation rate should be controlled simultaneity by the chemical reactions rate and the dissipation rate of turbulent eddies. A hybrid particle turbulent transport controlled rate and soot oxidation rate model is present in this paper and Soot formation and oxidation processes have been modeled according to this model. A reasonable agreement of the measured and computed data of in-cylinder pressure, soot, and NO emissions for different engine operation conditions has been made. The precision of simulated soot concentration is improved compare with the commonly Hiroyasu—Nagel—Strickland (HNS) soot model.

Soot Formation Reaction Effect in Modeling Thermal Partial Oxidation of Jet-A

2014 ◽  
Author(s):  
Richard Scenna ◽  
Ashwani K. Gupta
Keyword(s):  
Experimental Data ◽  
Carbon Monoxide ◽  
Partial Oxidation ◽  
Kinetic Models ◽  
Soot Formation ◽  
Radical Formation ◽  
Fuel Reforming ◽  
Chemical Modeling ◽  
Formation Reaction ◽  
One Dimensional

The results obtained from the modeling of thermal partial oxidation of kerosene based Jet-A fuel are presented using one dimensional chemical modeling. Two detailed kinetic models for alkenes chemistry ranging between C8 to C16 were evaluated and compared against experimental data of thermal partial oxidation of Jet-A fuel. The key difference between these two kinetic models was the inclusion of model for soot formation reactions. Chemical modeling was performed using dodecane to represent Jet-A fuel. The results showed that the model with soot reactions was significantly more accurate in predicting reformate products from Jet-A. In particular, the formation of carbon monoxide, methane and acetylene closely followed the experimental data with the model that included soot formation reactions. The results revealed that the soot formation reactions promoted the smaller hydrocarbons to decompose via the alternate kinetic pathways and from additional radical formation. The results also reveal that the inclusions of soot formation reactions are critical in the modeling of thermal partial oxidation of fuels for fuel reforming.

A Comparative Performance Study of Soot Formation Models in Methane Elevated Pressure Non-Premixed Flames

2011 ◽  
Vol 110-116 ◽  
pp. 18-22 ◽  
Author(s):  
A. Yunardi ◽  
B. Elwina ◽  
Sylvia Novi ◽  
D. Wusnah ◽  
Bindar Yazid
Keyword(s):  
Experimental Data ◽  
Soot Formation ◽  
Elevated Pressure ◽  
Single Step ◽  
Performance Study ◽  
Ethylene Flame ◽  
Step Model ◽  
Radial Profiles ◽  
Dissipation Model ◽  
Soot Model

This paper presents results obtained from the application of a computational fluid dynamics (CFD) code Fluent 6.3 to modeling of elevated pressure methane non-premixed sooting flames. The study focuses on comparing the two soot models available in the code for the prediction of the soot level in the flames. A standard k-ε model and Eddy Dissipation model are utilized for the representation of flow field and combustion of the flame being investigated. For performance comparison study, a single step soot model of Khan and Greeves and two-step soot model proposed by Tesner are tested. The results of calculations are compared with experimental data of methane sooting flame taken from literature. The results of the study show that a combination of the standard k-ε turbulence model and eddy dissipation model is capable of producing reasonable predictions of temperature both in axial and radial profiles; although further downstream of the flame over-predicted temperature is evidence. With regard to soot model performance study, it shows that the two-step model clearly performed far better than the single-step model in predicting the soot level in ethylene flame at both axial and radial profiles. With a modification in the constant α of the soot formation equation, the two-step model was capable of producing prediction of soot level closer to experimental data. In contrast, the single-step soot model produced very poor results, leading to a significant under-prediction of soot levels in both flames. Although the Tesner’s soot model is simpler than the current available models, this model is still capable of providing reasonable agreement with experimental data, allowing its application for the purpose of design and operation of an industrial combustion system.

scholarly journals The Influence of the Distributed Reaction Regime on Fuel Reforming Conditions

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Richard Scenna ◽  
Ashwani K. Gupta
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Soot Formation ◽  
Product Distribution ◽  
Fuel Reforming ◽  
Length Scales ◽  
Reaction Regime ◽  
Available Information ◽  
Kinetics Of ◽  
Reforming Reactions

Previous works have demonstrated that the distributed reaction regime improved the reformate product distribution, prevented soot formation, and favored higher hydrogen yields. The experimental data from these works and additional literature focusing on individual reactions provided an insight into how the distributed reaction regime influenced the reformate product composition. The distributed reaction regime was achieved through the controlled entrainment of hot reactive products (containing heat, carbon dioxide, steam and reactive radicals and species) into the premixed fuel air mixture, elongating the chemical time and length scales. High velocity jets enhanced mixing, while shortening the time and length scales associated with transport. As some steam and carbon dioxide will form in the reforming process, it was theorized that the mixing of the entrained flow (containing heat, carbon dioxide, and steam) into the premixed fuel air mixture promoted dry and steam reforming reactions, improving conversion. The available information on chemical kinetics of reformation is rather limited. In this work, the activity and timescales of these reactions were determined from the available experimental data. This was then used to assess which reactions were active under Distributed Reforming conditions. These data help in the design and development of advanced reformers using distributed reforming conditions.

scholarly journals An Improved Phenomenological Soot Formation Submodel for Three-Dimensional Diesel Engine Simulations: Extension to Agglomeration of Particles into Clusters

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Joan Boulanger ◽  
W. Stuart Neill ◽  
Fengshan Liu ◽  
Gregory J. Smallwood
Keyword(s):  
Experimental Data ◽  
Diesel Engine ◽  
Oxidation Process ◽  
Soot Formation ◽  
Three Dimensional ◽  
Soot Oxidation ◽  
Heavy Duty ◽  
Heavy Duty Diesel Engine ◽  
Agglomeration Effects ◽  
Heavy Duty Diesel

An extension to a phenomenological submodel for soot formation to include soot agglomeration effects is developed. The improved submodel was incorporated into a commercial computational fluid dynamics code and was used to investigate soot formation in a heavy-duty diesel engine. The results of the numerical simulation show that the soot oxidation process is reduced close to the combustion chamber walls, due to heat loss, such that larger soot particles and clusters are predicted in an annular volume at the end of the combustion cycle. These results are consistent with available in-cylinder experimental data and suggest that the cylinder of a diesel engine must be split into several volumes, each of them with a different role regarding soot formation.

scholarly journals Soot Emission Analysis in Combustion of Biogas Diesel Dual Fuel Engine

2017 ◽  
Vol 2 (1) ◽  
pp. 67 ◽  
Author(s):  
Bui Van Ga ◽  
Bui Thi Minh Tu
Keyword(s):  
Equivalence Ratio ◽  
Engine Speed ◽  
Soot Formation ◽  
Dual Fuel ◽  
Diffusion Combustion ◽  
Exhaust Gas ◽  
Soot Emission ◽  
Soot Concentration ◽  
Emission Analysis ◽  
Peak Value

Soot emission in bio-gas diesel dual fuel engine has been analyzed by numerical simulation with 2-stape soot formation model of Magnussen. The result shows that soot formation mainly occurred in diffusion combustion phase of diesel pilot jet. Soot peak value is proportional to the first peak value of ROHR, and is found at around the same crank angle position with the second peak of ROHR. At a given engine speed and diesel content in the fuel, the highest soot peak value is obtained with slightly rich mixture whereas soot concentration in exhaust gas increases monotonically with increasing equivalence ratio. Increasing diesel content in the fuel increases both soot peak value and soot concentration in exhaust gas. At a given equivalence ratio and diesel content in the fuel, engine speed has a moderate effect on soot formation rate but a significant effect on soot combustion rate. Soot concentration in the exhaust gas practically vanished as equivalence ratio under 0.98 and 15% diesel content in the fuel. This is the ideal operation regime of bio-gas diesel dual fuel engine in view of soot emission control.

scholarly journals Development of a soot concentration estimator for industrial combustion applications

2021 ◽  
Author(s):  
Sepehr Bozorgzadeh
Keyword(s):  
Adverse Effects ◽  
Human Health ◽  
Atmospheric Pressure ◽  
Soot Formation ◽  
Soot Concentration ◽  
Important Goal ◽  
Cfd Simulations ◽  
Preliminary Results ◽  
Volume Fractions ◽  
Entire History

Soot emissions from combustion devices are known to have adverse effects on the environment and human health. Thus, the development of techniques to reduce soot formation and emissions remains an important goal of researchers and industry. This study leverages existing knowledge in soot modelling and soot formation fundamentals to develop a stand-alone, computationally inexpensive soot concentration estimator, to be linked to CFD simulations as a post-processor. The estimator was developed using fluid parcel tracking techniques that can track entire history to which a particle or fluid parcel has been exposed. Preliminary results suggest that the estimator is capable of predicting peak and emitted soot volume fractions in atmospheric pressure flames.

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