Investigation of Spectral Radiation Heat Transfer and NOx Emission in a Glass Furnace

2000 ◽  
Author(s):  
B. Golchert ◽  
C. Q. Zhou ◽  
S. L. Chang ◽  
M. Petrick
Keyword(s):  
Heat Transfer ◽  
Glass Furnace ◽  
Radiation Heat Transfer ◽  
Flow Characteristics ◽  
Operating Conditions ◽  
Transfer Model ◽  
Radiation Heat ◽  
Spectral Radiation ◽  
Radiation Emission ◽  
The Impact

Abstract A comprehensive radiation heat transfer model and a reduced NOx kinetics model were coupled with a computational fluid dynamics (CFD) code and then used to investigate the radiation heat transfer, pollutant formation and flow characteristics in a glass furnace. The radiation model solves the spectral radiative transport equation in the combustion space of emitting and absorbing media, i.e., CO2, H2O, and soot and emission/reflection from the furnace crown. The advanced numerical scheme for calculating the radiation heat transfer is extremely effective in conserving energy between radiation emission and absorption. A parametric study was conducted to investigate the impact of operating conditions on the furnace performance with emphasis on the investigation into the formation of NOx.

Combined Conduction and Radiation Heat Transfer in Porous Materials Heated by Intense Solar Radiation

1985 ◽  
Vol 107 (1) ◽  
pp. 29-34 ◽  
Author(s):  
L. K. Matthews ◽  
R. Viskanta ◽  
F. P. Incropera
Keyword(s):  
Heat Transfer ◽  
Radiation Heat Transfer ◽  
Plane Layer ◽  
Single Scattering ◽  
Dominant Mode ◽  
Radiative Properties ◽  
Maximum Temperature ◽  
Transfer Model ◽  
Radiation Heat ◽  
Flux Approximation

An analysis is presented to predict the heat transfer characteristics of a plane layer of a semitransparent, high-temperature, porous material which is irradiated by an intense solar flux. A transient, combined conduction and radiation heat transfer model, which is based on a two-flux approximation for the radiation, is used to predict the temperature distribution and heat transfer in the material. Numerical results have been obtained using thermophysical and radiative properties of zirconia as a typical material. The results show that radiation is an important mode of heat transfer, even when the opacity of the material is large (τL > 100). Radiation is the dominant mode of heat transfer in the front third of the material and comparable to conduction toward the back. The semitransparency and high single scattering albedo of the zirconia combine to produce a maximum temperature in the interior of the material.

scholarly journals Radiation heat transfer model using Monte Carlo ray tracing method on hierarchical ortho-Cartesian meshes and non-uniform rational basis spline surfaces for description of boundaries

2014 ◽  
Vol 35 (2) ◽  
pp. 65-92 ◽  
Author(s):  
Paweł Kuczyński ◽  
Ryszard Białecki
Keyword(s):  
Heat Transfer ◽  
Ray Tracing ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Rational Basis ◽  
Radiation Heat ◽  
Cartesian Meshes ◽  
Spline Surfaces ◽  
Nurbs Surfaces ◽  
Transfer Problems

Abstract The paper deals with a solution of radiation heat transfer problems in enclosures filled with nonparticipating medium using ray tracing on hierarchical ortho-Cartesian meshes. The idea behind the approach is that radiative heat transfer problems can be solved on much coarser grids than their counterparts from computational fluid dynamics (CFD). The resulting code is designed as an add-on to OpenFOAM, an open-source CFD program. Ortho-Cartesian mesh involving boundary elements is created based upon CFD mesh. Parametric non-uniform rational basis spline (NURBS) surfaces are used to define boundaries of the enclosure, allowing for dealing with domains of complex shapes. Algorithm for determining random, uniformly distributed locations of rays leaving NURBS surfaces is described. The paper presents results of test cases assuming gray diffusive walls. In the current version of the model the radiation is not absorbed within gases. However, the ultimate aim of the work is to upgrade the functionality of the model, to problems in absorbing, emitting and scattering medium projecting iteratively the results of radiative analysis on CFD mesh and CFD solution on radiative mesh.

Improved MSMGFSK Models Apply to Gas Radiation Heat Transfer Calculation of Exhaust System of TBCC

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Haiyang Hu ◽  
Qiang Wang
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Thermal Emission ◽  
Radiation Heat Transfer ◽  
Exhaust System ◽  
Combined Cycle ◽  
Large Temperature ◽  
Radiation Heat ◽  
Full Spectrum ◽  
Radiation Emission

The multiscale multigroup full-spectrum k-distribution (MSMGFSK) model was improved to adapt to radiation heat transfer calculations of combustion gas flow field with large temperature and pressure gradient. The improvements in calculation accuracy resulting from new sorting strategy of the spectral absorption coefficients were validated using a series of semi-1D problem in which strong temperature, pressure, and mole fraction inhomogeneities were present. A simpler method to attain compatibility between the MSMGFSK model and the gray-wall radiation emission has been established and validated. Finally, estimates are given for the calculation of wall radiation heat transfer characteristics and thermal emission imaging of the exhaust system of the parallel turbine-based combined cycle (TBCC) engine, using finite volume method (FVM) and ray trace method (RT), respectively.

scholarly journals Radiation heat transfer between human and cryocabin walls

2021 ◽  
Vol 2119 (1) ◽  
pp. 012146
Author(s):  
I A Burkov ◽  
S I Khutsieva ◽  
V A Voronov
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Human Body ◽  
Transfer Problem ◽  
Radiation Heat Transfer ◽  
Vertical Wall ◽  
Heat Transfer Problem ◽  
Radiation Heat ◽  
The Impact

Abstract The paper considers the particular case of intensive radiation heat transfer in the system consisting of a human body and cryocabin walls of cryosauna. Calculations for three models have been made, namely, human-vertical wall, which is arranged parallel to a human, human-vertical wall, which is positioned at a certain angle, and a human-cryosauna. Analytical calculations are compared with Ansys-bassed numerical calculations. The impact of radiation heat transfer in this radiation-convective heat transfer problem is estimated. Conclusions are drawn about taking into account the radiation heat transfer and a rational method for calculating this heat transfer problem.

Radiation Heat Transfer in Fluidized Beds: A Comparison of Exact and Simplified Approaches

1994 ◽  
Vol 116 (3) ◽  
pp. 652-659 ◽  
Author(s):  
G. Flamant ◽  
J. D. Lu ◽  
B. Variot
Keyword(s):  
Heat Transfer ◽  
Fluidized Beds ◽  
Radiation Heat Transfer ◽  
Discrete Ordinates ◽  
Transfer Model ◽  
Radiation Heat ◽  
Flux Divergence ◽  
Transfer Coefficients ◽  
Variable Porosity ◽  
Radiation Exchange

Radiation heat transfer at heat exchanger walls in fluidized beds has never been examined through a complete formulation of the problem. In this paper a wall-to-bed heat transfer model is proposed to account for particle convection, gas convection, and radiation exchange in a variable porosity medium. Momentum, energy, and intensity equations are solved in order to determine the velocity, temperature, radiative heat flux profiles and heat transfer coefficients. The discrete-ordinates method is used to compute the radiative intensity equation and the radiative flux divergence in the energy equation. Both the gray and the non-gray assumptions are considered, as well as dependent and independent scattering. The exact solution obtained is compared with several simplified approaches. Large differences are shown for small particles at high temperature but the simplified solutions are valid for large particle beds. The dependency of radiative contribution on controlling parameters is discussed.

A CFD Assessment of Engine Core Zone Casing Heat Transfer

2019 ◽  
Author(s):  
Zixiang Sun ◽  
Nicholas J. Hills ◽  
Richard Scott
Keyword(s):  
Heat Transfer ◽  
Radiation Heat Transfer ◽  
Convection Heat Transfer ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Steady Flows ◽  
Radiation Heat ◽  
Core Zone ◽  
The Public ◽  
The Core

Abstract A systematic CFD investigation was conducted to assess the core zone (CZ) casing heat transfer of a large civil aircraft engine. Three key engine operating conditions, maximum takeoff (MTO), cruise (CRZ) and ground idle (GI) were analyzed. Steady flows were assumed. Turbulence was simulated using the realizable k-epsilon model in conjunction with the scalable wall function. Buoyancy effect was taken into account. Radiation was calculated using the discrete ordinate (DO) model. It was shown that the forced convection heat transfer dominates in most of the casing surface in the core zone, and radiation is of second importance in general. However, in some areas where both convection and radiation heat transfer are weak but the latter is relatively greater in magnitude than the former, radiation heat transfer could thus become dominant. In addition, the overall impact of radiation on casing heat transfer increases from MTO to CRZ and GI conditions, as the strength of engine load decreases. The overall effect of buoyancy on casing heat transfer is small, but could be noticeable in some local areas where flow velocity is low. The insight into heat transfer features on the engine core zone casing supported by quantified CFD evidences is the first in the public domain, as far as authors are aware.

scholarly journals Numerical simulation of reacting flow in the combustion chamber and study of the impact of turbulent diffusion coefficients

2020 ◽  
Vol 12 (9) ◽  
pp. 168781402095497
Author(s):  
Evgenij Strokach ◽  
Igor Borovik ◽  
Fang Chen
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Chemical Reactions ◽  
Turbulence Model ◽  
Turbulent Diffusion ◽  
Diffusion Coefficients ◽  
Radiation Heat Transfer ◽  
Mixing Efficiency ◽  
Radiation Heat ◽  
The Impact

A methodology for combustion modeling with complex mixing and thermodynamic conditions, especially in thrusters, is still under development. The resulting flow and propulsion parameters strongly depend on the models used, especially on the turbulence model as it determines the mixing efficiency. In this paper, the effect of the sigma-type turbulent diffusion coefficients arriving in the diffusion term of the turbulence model is studied. This study was performed using complex modeling, considering the conjugate effect of several physical phenomena such as turbulence, chemical reactions, and radiation heat transfer. To consider the varying turbulent Prandtl, an algebraic model was implemented. An adiabatic steady diffusion Flamelet approach was used to model chemical reactions. The P1 differential model with a WSGG spectral model was used for radiation heat transfer. The gaseous oxygen (GOX) and methane (GCH4) operating thruster developed at the Chair of turbomachinery and Flight propulsion of the Technical University of Munich (TUM) is taken as a test case. The studies use the 3D RANS approach using the 60° sector as the modeling domain. The normalized and absolute pressures, the integral and segment averaged heat flux are compared to numerical results. The wall heat fluxes and pressure distributions show good agreement with the experimental data, while the turbulent diffusion coefficients mostly influence the heat flux.

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