scholarly journals Pressure effects on radiative heat transfer in sooting turbulent diffusion flames

2020 ◽  
Vol 245 ◽  
pp. 106906 ◽  
Author(s):  
Fatiha Nmira ◽  
Yuying Liu ◽  
Jean-Louis Consalvi ◽  
Frederic Andre ◽  
Fengshan Liu
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Turbulent Diffusion ◽  
Radiative Heat ◽  
Diffusion Flames ◽  
Pressure Effects ◽  
Turbulent Diffusion Flames

Numerical Investigation of Soot Formation in Turbulent Diffusion Flames Using Moss-Brookes Model

2014 ◽  
Author(s):  
Mannedhar Reddy ◽  
Ashoke De
Keyword(s):  
Heat Transfer ◽  
Absorption Coefficient ◽  
Radiative Heat Transfer ◽  
Turbulent Diffusion ◽  
Radiative Heat ◽  
Diffusion Flames ◽  
Soot Formation ◽  
Effective Absorption Coefficient ◽  
Turbulent Diffusion Flames ◽  
Air Jet

In the present work, two different turbulent diffusion flames are investigated for soot predictions using the presumed shape multi-environment Eulerian PDF (EPDF) as turbulence-chemistry closure. In this approach, the chemical equation is represented by multiple reactive scalars and finite number of Delta functions are used to describe the shape of joint composition PDF, while the truncated series expansion in spherical harmonics (P1 approximation) is used to solve the radiative heat-transfer equation. The absorption coefficient is modeled using the weighted sum of gray gases model (WSGG) considering four fictitious gases. The soot volume fraction is predicted using acetylene based soot inception model (Moss-Brookes model). The model accounts for inception, surface growth and oxidation processes of soot. An equilibrium based approach is used to determine the OH radical concentration, required for soot oxidation. A single variable PDF in terms of temperature is used to include the turbulence-chemistry effects on soot. An effective absorption coefficient is calculated to include the influence of radiative heat transfer on soot. The combined tool is used to determine the soot formation in two hydrocarbon flames (Delft flame III, pilot stabilized natural gas flame and an unconfined C2H4/air jet flame). The soot formation rate decreases with the inclusion of radiation for both the flames and indicate the need for delineation of radiative heat transfer. The effects of soot-turbulence interaction are consistent with available literature. The effect of collision efficiency on oxidation rate can be clearly explicated from the predictions of C2H4/air flame.

scholarly journals High fidelity radiative heat transfer models for high-pressure laminar hydrogen–air diffusion flames

2014 ◽  
Vol 18 (6) ◽  
pp. 607-626 ◽  
Author(s):  
Jian Cai ◽  
Shenghui Lei ◽  
Adhiraj Dasgupta ◽  
Michael F. Modest ◽  
Daniel C. Haworth
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Diffusion Flames ◽  
High Fidelity ◽  
Air Diffusion ◽  
Transfer Models

Radiative Heat Transfer in High-Pressure Laminar Hydrogen-Air Diffusion Flames Using Spherical Harmonics and K-Distributions

2012 ◽  
Author(s):  
Jian Cai ◽  
Shenghui Lei ◽  
Adhiraj Dasgupta ◽  
Michael F. Modest ◽  
Dan C. Haworth
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Water Vapor ◽  
Spherical Harmonics ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Diffusion Flames ◽  
Transport Equations ◽  
Full Spectrum ◽  
Air Jet

Radiative heat transfer is studied numerically for high-pressure laminar H2-air jet diffusion flames, with pressure ranging from 1 to 30 bar. Water vapor is assumed to be the only radiatively participating species. A full spectrum k-distribution spectral model is used. Narrowband k-distributions of water vapor are calculated and databased from the HITEMP 2010 database, which claims to retain accuracy up to 4000K. The full-spectrum k-distributions are assembled from their narrowband counterparts to yield high accuracy with little additional computational cost. The radiative transfer equation (RTE) is solved using various spherical harmonics methods, such as P1, simplified P3 (SP3) and simplified P5 (SP5). The resulting partial differential equations as well as other transport equations in the laminar diffusion flames are discretized with the finite-volume method in OpenFOAM. Differential diffusion effects which are important in laminar hydrogen flames are also included in the scalar transport equations. It was found that peak flame temperature becomes less sensitive to radiation at higher pressure, and that radiation causes cooling in the downstream region. Differences between the three spherical harmonics RTE solver were found negligible below 5 bar.

scholarly journals Numerical prediction of coaxial flow diffusion flames with radiative heat transfer.

1989 ◽  
Vol 55 (510) ◽  
pp. 523-528
Author(s):  
Masashi KATSUKI ◽  
Yukio MIZUTANI ◽  
Akihiro ANDO ◽  
Yoshihiro HATTORI ◽  
Yoichi JINJA ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Diffusion Flames ◽  
Numerical Prediction

scholarly journals Numerical Prediction of Coaxial Flow Diffusion Flames with Radiative Heat Transfer

1990 ◽  
Vol 33 (4) ◽  
pp. 772-777
Author(s):  
Masashi KATSUKI ◽  
Yukio MIZUTANI ◽  
Akihiro ANDO ◽  
Yoshihiro HATTORI ◽  
Yoichi JINJA ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Diffusion Flames ◽  
Numerical Prediction

Numerical Simulation of Jet Diffusion Flames With Radiative Heat Transfer Modeling

2005 ◽  
Author(s):  
Mario Baburic´ ◽  
Reinhard Tatschl ◽  
Neven Duic´
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Radiative Heat Transfer ◽  
Diffusion Flame ◽  
Radiative Heat ◽  
Diffusion Flames ◽  
Flamelet Model ◽  
Jet Flame ◽  
Combustion Modeling ◽  
Jet Diffusion Flames

Beside appropriate turbulence and combustion modeling, the problem of an accurate prediction of turbulent diffusion flames usually requires accurate radiative heat transfer predictions as well. In this paper it is shown that the inclusion of radiation modeling into the overall numerical simulation is important if accurate temperature profiles are needed. Two different jet diffusion flame configurations are simulated in this work — a diluted hydrogen jet flame (80% H2 and 20% He by volume) [1–4], and a piloted methane jet diffusion flame (flame D) [5, 6]. The predictions are compared to experimental data. Radiation is modeled by a conservative discrete transfer radiation method (DTRM) [7, 8]. Turbulence is modeled by a classical k-ε and by a hybrid procedure, as proposed in [9]. Combustion modeling is based on the stationary laminar flamelet model (SLFM) [10], where the combustion/turbulence interaction is accomplished via the presumed β probability density function (β-PDF).

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