Weighted Sum of Gray Gas Modeling for Nongray Radiation in Combusting Environment Using the Hybrid Solution Methodology

Yadav, Rakesh; Kushari, Abhijit; Verma, Atul Kumar; Eswaran, V.

doi:10.1080/10407790.2013.784147

Cited by 14 publications

(12 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The details of the approach can be found in Rakesh et al [16]. Total emissivity over a distance S is given by Eq.…”

Section: Radiation Modelingmentioning

confidence: 99%

“…The non-gray behaviour is represented using fourfictitious gray gases, whose weight functions and absorption coefficients are calculated from Smiths et al[30] as a function of H2O and CO2 partial pressures. The details of the approach can be found in Rakesh et al[16].4.1 Modeling DetailsAs the flow is symmetric, an axisymmetric 2D grid is used in the present computational work. The diameter of the pilot fuel inlet is determined from the equivalent area of the 12 holes on the rim.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Effect of precursors and radiation on soot formation in turbulent diffusion flame

Reddy

Yadav³

2015

Fuel

Self Cite

View full text Add to dashboard Cite

a b s t r a c tSoot formation in 'Delft Flame III', a pilot stabilized turbulent diffusion flame burning natural gas/air, is investigated using ANSYS FLUENT by considering two different approaches for soot inception. In the first approach soot inception is based on the formation rate of acetylene, while the second approach considers the formation rate of two and three-ringed aromatics to describe the soot inception (Hall et al., 1997). Transport equations are solved for soot mass fraction and radical nuclei concentration to describe inception, coagulation, surface growth, and oxidation processes. The turbulent-chemistry interactions and soot precursors are described by the steady laminar flamelet model (SLFM). Two chemical mechanisms GRI 3.0 (Gregory et al.) and POLIMI (Ranzi et al., 2012) are used to represent the effect of species concentration on soot formation. The radiative properties of the medium are included based on the nongray modeling approach by considering four factious gases; the weighted sum of gray gas (WSGGM) approach is used to model the absorption coefficient. The effect of soot on radiative transfer is modeled in terms of effective absorption coefficient of the medium. A beta probability density function (b-PDF) in terms of normalized temperature is used to describe the effect of turbulence on soot formation. The results clearly elucidate the strong effect of radiation and species concentration on soot volume fraction predictions. Due to increase in radiative heat loss with soot, flame temperature decreases slightly. The inclusion of ethylene has less synergic effect than that of both benzene and ethylene. Both cases have less impact on the nucleation of soot. The increase in soot volume fraction with soot-turbulence interaction is in consistence with the DNS predictions.

show abstract

“…The details of the approach can be found in Rakesh et al [16]. Total emissivity over a distance S is given by Eq.…”

Section: Radiation Modelingmentioning

confidence: 99%

mentioning

confidence: 99%

Effect of precursors and radiation on soot formation in turbulent diffusion flame

Reddy

Yadav³

2015

Fuel

Self Cite

View full text Add to dashboard Cite

show abstract

“…Soufiani and Djavdan [ 10 ] proposed a five-order polynomial for gas combustion, where P w / P c = 2. After that a lot of efforts were given to model the radiative properties from semitransparent media containing a mixture of nongray gases and soot [ 11 , 12 ] which was applied for analyzing the radiative heat transfer inside the furnace [ 13 ]. Among the different methods of modeling the combusting environments such as inverse methodologies, hybrid method, discrete-ordinates method, and finite volume method [ 14 – 17 ], the zone method is more practical and many attempts on radiative heat transfer analysis were conducted based on this method [ 18 – 20 ].…”

Section: Introductionmentioning

confidence: 99%

Extension of Weighted Sum of Gray Gas Data to Mathematical Simulation of Radiative Heat Transfer in a Boiler with Gas-Soot Media

Gharehkhani

Nouri-Borujerdi

Kazi

et al. 2014

The Scientific World Journal

View full text Add to dashboard Cite

In this study an expression for soot absorption coefficient is introduced to extend the weighted-sum-of-gray gases data to the furnace medium containing gas-soot mixture in a utility boiler 150 MWe. Heat transfer and temperature distribution of walls and within the furnace space are predicted by zone method technique. Analyses have been done considering both cases of presence and absence of soot particles at 100% load. To validate the proposed soot absorption coefficient, the expression is coupled with the Taylor and Foster's data as well as Truelove's data for CO2-H2O mixture and the total emissivities are calculated and compared with the Truelove's parameters for 3-term and 4-term gray gases plus two soot absorption coefficients. In addition, some experiments were conducted at 100% and 75% loads to measure furnace exit gas temperature as well as the rate of steam production. The predicted results show good agreement with the measured data at the power plant site.

show abstract

“…In the present work, the absorptive coefficient is modeled by the weighted sum of gray gases (WSGG) model. The non-gray medium of is represented by four fictions gases and details of the approach can be found in Rakesh et al 21 The effect on radiative heat transfer by soot formation is included by the absorption coefficient of soot and given as equation (17).…”

Section: Radiation Modelingmentioning

confidence: 99%

“…In the first approach, the soot precursor was consider as a linear function of acetylene concentration as given in equation (21). In the second, the soot precursor was considered as a function of two and three ringed aromatic species, given in equation (23) …”

Section: Soot Modelingmentioning

confidence: 99%

Numerical modeling of soot formation in a turbulent C₂H₄/air diffusion flame

Busupally

2016

International Journal of Spray and Combustion Dynamics

View full text Add to dashboard Cite

Soot formation in a lifted C 2 H 4 -Air turbulent diffusion flame is studied using two different paths for soot nucleation and oxidation; by a 2D axisymmetric RANS simulation using ANSYS FLUENT 15.0. The turbulence-chemistry interactions are modeled using two different approaches: steady laminar flamelet approach and flamelet-generated manifold. Chemical mechanism is represented by POLIMI to study the effect of species concentration on soot formation. P1 approximation is employed to approximate the radiative transfer equation into truncated series expansion in spherical harmonics while the weighted sum of gray gases is invoked to model the absorption coefficient while the soot model accounts for nucleation, coagulation, surface growth, and oxidation. The first route for nucleation considers acetylene concentration as a linear function of soot nucleation rate, whereas the second route considers two and three ring aromatic species as function of nucleation rate. Equilibrium-based and instantaneous approach has been used to estimate the OH concentration for soot oxidation. Lee and Fenimore-Jones soot oxidation models are studied to shed light on the effect of OH on soot oxidation. Moreover, the soot-radiation interactions are also included in terms of absorption coefficient of soot. Furthermore, the soot-turbulence interactions have been invoked using a temperature/mixture fraction-based single variable PDF. Both the turbulence-chemistry interaction models are able to accurately predict the flame liftoff height, and for accurate prediction of flame length, radiative heat loss should be accounted in an accurate way. The soot-turbulence interactions are found sensitive to the PDF used in present study.

show abstract

Weighted Sum of Gray Gas Modeling for Nongray Radiation in Combusting Environment Using the Hybrid Solution Methodology

Cited by 14 publications

References 28 publications

Effect of precursors and radiation on soot formation in turbulent diffusion flame

Effect of precursors and radiation on soot formation in turbulent diffusion flame

Extension of Weighted Sum of Gray Gas Data to Mathematical Simulation of Radiative Heat Transfer in a Boiler with Gas-Soot Media

Numerical modeling of soot formation in a turbulent C₂H₄/air diffusion flame

Contact Info

Product

Resources

About

Weighted Sum of Gray Gas Modeling for Nongray Radiation in Combusting Environment Using the Hybrid Solution Methodology

Cited by 14 publications

References 28 publications

Effect of precursors and radiation on soot formation in turbulent diffusion flame

Effect of precursors and radiation on soot formation in turbulent diffusion flame

Extension of Weighted Sum of Gray Gas Data to Mathematical Simulation of Radiative Heat Transfer in a Boiler with Gas-Soot Media

Numerical modeling of soot formation in a turbulent C2H4/air diffusion flame

Contact Info

Product

Resources

About

Numerical modeling of soot formation in a turbulent C₂H₄/air diffusion flame