Numerical simulation of the interaction between turbulence and radiation in reactive flows

Coelho, Pedro J.

doi:10.1016/j.pecs.2006.11.002

Cited by 199 publications

(118 citation statements)

References 106 publications

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“…An early study by Foster [40] showed that calculation of the mean transmissivity from a turbulent flame must take turbulent fluctuations into account. Coelho [37] showed that, in the presence of turbulent fluctuations, the turbulent fluctuation of the absorption coefficient increases the transmissivity of the medium if the pdf of the absorption coefficient is Gaussian and his observation is in agreement with the theoretical findings of Foster [40].…”

Section: Introductionsupporting

confidence: 78%

“…(37) or (38) requires deconvolution and makes these problems ill-posed and, therefore these equations cannot be inverted directly to obtain all the parameters. Inverse procedures are required to solve them numerically.…”

Section: Inverse Calculationmentioning

confidence: 99%

“…Most work in TRI has been devoted to the study of turbulence on total radiative heat transfer emitted by a hot medium. A rather different challenge is accurate modeling of the correlation between local instantaneous radiation intensity along the optical path and local absorption coefficients [37]. Most works have neglect this correlation based on the suggestion and arguments given by Kabashnikov and Myasnikova [38] that, if the mean free path for radiation is much larger than the turbulence length scale, then the local intensity is governed by fluctuations far away, and thus should be only weakly correlated with local absorption coefficient fluctuations.…”

Section: Introductionmentioning

confidence: 99%

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Optical Determination of Temperature and Species Concentration for Homogeneous Turbulent Gas Medium

Ren¹,

Modest²

2016

Proceeding of First Thermal and Fluids Engineering Summer Conference

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In this study, we present an inverse calculation model to reconstruct time-averaged temperature, species concentration and their root mean square (rms) values from optical synthetic measurements for a homogeneous turbulent gaseous medium. The model is based on line-of-sight spectral transmissivity synthetic measurements, and time-averaged transmissivities and their rms values are successfully related to time-averaged temperatures, species concentrations and their rms values by considering interaction between turbulence and radiation (TRI). The turbulence length scale is also retrieved simultaneously with the turbulent scalars. In order to validate the model, a stochastic approach is used to generate synthetic turbulent fields (fluctuations of temperature and species concentration), and measured spectra are synthesized through calculations from HITEMP 2010 for different spectral bands of CO 2 , H 2 O and CO.

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Section: Introductionsupporting

confidence: 78%

Section: Inverse Calculationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Optical Determination of Temperature and Species Concentration for Homogeneous Turbulent Gas Medium

Ren¹,

Modest²

2016

Proceeding of First Thermal and Fluids Engineering Summer Conference

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“…In considering the important role played by radiation heat transfer in such problems [15], the turbulence radiation interaction (TRI) resulting from the fluctuations of temperature and soot volume fraction in the flame have been taken into account in the radiation transfer equation (RTE) using an optically thin fluctuation approximation (OPFA) [16,17] The…”

Section: Mathematical Modelmentioning

confidence: 99%

Impact of solid fuel particle size upon the propagation of a surface fire through a homogeneous vegetation layer

Morvan¹,

Lamorlette²

2014

Fire Saf. Sci.

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The aim of this paper is to investigate the role played by the size (thickness) of solid fuel particles upon both the heat transfer and the propagation of a surface fire through a homogeneous vegetation layer. Because all the interactions (mass, momentum, and heat transfer) between the solid fuel layer and the gas phase occur at the interface between these two media, the surface area to volume (SA/V) ratio (inversely proportional to the thickness of the solid fuel particles), which appears in the expression of the specific surface separating these two phases, must affect, more or less significantly, the fire dynamics. This problem has been studied numerically, using a multiphase formulation. Various variables, such as the temperature of the solid fuel, the temperature of the gas, the fire residence time and the heat flux by radiation and convection have been analyzed, in order to understand the role played by the SA/V upon the behaviour of the fire.

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“…Além disso, sua Plena 11, 081302 (2015) 2 caracterização representa um problema altamente desafiador pela elevada complexidade da fenomenologia física envolvida [1,2].…”

Section: Introductionunclassified

Estudo numérico de escoamentos turbulentos com convecção forçada em cavidades cilíndricas: comparação entre LES e RANS

et al. 2015

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O presente trabalho apresenta um estudo numérico comparando o emprego da Simulação de Grandes Escalas (LES) e Modelagem Clássica (RANS) com o modelo k -ε para a predição dos campos médios e estatísticos em um escoamento turbulento com convecção forçada em cavidades cilíndricas (escoamento de base cisalhante livre) a Re D = 22000 e Pr = 0.71. No âmbito da convecção forçada, o principal propósito é verificar se o uso das diferentes metodologias para abordagem da turbulência pode conduzir a diferenças consideráveis nos fluxos convectivos nas superfícies da cavidade. Além disso, as diferenças dos campos médios e estatísticos de temperatura também são importantes para futuras análises de escoamentos com mecanismos combinados de convecção e radiação térmica em meios participantes, i.e., investigando a influência das Interações Turbulência-Radiação (TRI). As equações de conservação são resolvidas através do Método de Volumes Finitos (FVM). Os resultados revelaram que o jato apresentou uma maior penetração na cavidade cilíndrica para a simulação realizada com LES, enquanto um maior espalhamento radial foi observado no caso com o modelo RANS k -ε. Apesar de apresentarem uma tendência similar, diferenças significativas foram observadas para os campos médios, estatísticos e fluxos convectivos preditos com LES e RANS. Palavras-chave: LES, RANS, turbulência.The present work presents a numerical study comparing the employment of Large Eddy Simulation (LES) and Reynolds Averaged Navier-Stokes (RANS) with k -ε model for prediction of time-averaged and statistics fields for a forced convective turbulent flow in cylindrical cavities (free shear flow) at Re D = 22000 and Pr = 0.71. In the forced convective framework, the main purpose is to verify whether the use of different methodologies for turbulence approach can led to large differences in convective fluxes in the cavity surfaces. Moreover, the differences between the time-averaged fields of temperature and its statistics predicted with both methods are important for future analyses of turbulent flows with combined convective and radiative transfer in participant medium, i.e., investigating the Turbulence-Radiation Interactions (TRI). The conservation equations are solved by means of Finite Volume Method (FVM). Results revealed that the jet showed a higher penetration into the cylindrical cavity for simulation with LES, while a larger scattering in the radial direction is noticed for the simulations with RANS k -ε. In spite of the qualitatively similarity, it was noticed strongly differences between time-averaged, statistics and convective fluxes predicted with LES and RANS.

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Numerical simulation of the interaction between turbulence and radiation in reactive flows

Cited by 199 publications

References 106 publications

Optical Determination of Temperature and Species Concentration for Homogeneous Turbulent Gas Medium

Optical Determination of Temperature and Species Concentration for Homogeneous Turbulent Gas Medium

Impact of solid fuel particle size upon the propagation of a surface fire through a homogeneous vegetation layer

Estudo numérico de escoamentos turbulentos com convecção forçada em cavidades cilíndricas: comparação entre LES e RANS

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