The Experts below are selected from a list of 8709 Experts worldwide ranked by ideXlab platform
Rogério Martins Saldanha Da Gama - One of the best experts on this subject based on the ideXlab platform.
-
The nonlinear conduction/Radiation Heat Transfer phenomenon represented as the limit of a sequence of linear problems
International Communications in Heat and Mass Transfer, 1998Co-Authors: Rogério Martins Saldanha Da GamaAbstract:Abstract In this work it is presented a procedure for constructing the solution of conduction/Radiation Heat Transfer problems (inherently nonlinear) from a sequence of linear problems. It is shown that the solutions of these linear problems give rise to a nondecreasing sequence (always convergent) whose limit is exactly the solution of the original nonlinear conduction/Radiation Heat Transfer problem. In addition it is presented a way for estimating the error at each iteration. A particular example is considered to illustrate the procedure.
-
the nonlinear conduction Radiation Heat Transfer phenomenon represented as the limit of a sequence of linear problems
International Communications in Heat and Mass Transfer, 1997Co-Authors: Rogério Martins Saldanha Da GamaAbstract:Abstract In this work it is presented a procedure for constructing the solution of conduction/Radiation Heat Transfer problems (inherently nonlinear) from a sequence of linear problems. It is shown that the solutions of these linear problems give rise to a nondecreasing sequence (always convergent) whose limit is exactly the solution of the original nonlinear conduction/Radiation Heat Transfer problem. In addition it is presented a way for estimating the error at each iteration. A particular example is considered to illustrate the procedure.
Shigenao Maruyama - One of the best experts on this subject based on the ideXlab platform.
-
Radiation Heat Transfer Analysis in a Semitransparent Single Crystal with Specular Surfaces: Application of REM2
Numerical Heat Transfer Part A: Applications, 2012Co-Authors: Keita Abe, Ken-ichi Sugioka, Masaki Kubo, Takao Tsukada, Shigenao MaruyamaAbstract:In this work, to numerically analyze Radiation Heat Transfer in the Czochralski (CZ) single crystal growth of oxide, the Radiation element method by ray emission model (REM2) was considered for application. Here, REM2 was improved so that the Radiation Heat Transfer through a transparent specular interface between media with arbitrary three-dimensional configurations and different refractive indices can be analyzed. The improved method was verified of its validity by comparing its results with the numerical results of previous works. Then, the effects of the optical thickness and refractive index of oxide crystals on the temperature distributions in the crystals were numerically investigated, considering a simplified model of the CZ furnace.
-
Radiation Heat Transfer between arbitrary three-dimensional bodies with specular and diffuse surfaces
Numerical Heat Transfer Part A-applications, 1993Co-Authors: Shigenao MaruyamaAbstract:A numerical method is presented for predicting Radiation Heat Transfer from arbitrary bodies composed of numerous polygons. Each polygon is gray and has the comined characteristics of specular and diffuse surfaces. Both Heat flux and temperature can be specified arbitrarily on the surfaces. A new concept of view factors was introduced for analyzing Radiation Heat Transfer between specular and diffuse surfaces. A Radiation ray tracing method was adopted for estimating the view factors, and efficient vector operation and parallel processing were achieved for a supercomputer. The accuracy of the method was checked in comparison with analytical solutions for a simple configuration, and the effect of specular reflectivity was investigated. As a numerical example, Radiation Heat Transfer of a machine element and healer panels composed of 4388 polygons was demonstrated.
-
Radiation Heat Transfer Control by a Porous Layer and Gas Injection
JSME International Journal Series B, 1993Co-Authors: Shigenao MaruyamaAbstract:The possibility of Radiation Heat Transfer control by a combined model of an active thermal insulation system and a radiative converter was investigated. A semitransparent porous layer was placed between a high-temperature region and a low-temperature region, and gas was injected through the layer in the positive and negative directions. The mechanism of Heat Transfer is completely different for the positive and negative mass flux. By varying the mass flux of air between - 0.1 and 0 kg (m2s)-1, dimensionless radiative flux at the back face can be controlled between 2 X 10-4 and 0.1. In this region, the porous layer behaves as the active thermal insulation system, and the mechanism of Radiation Heat Transfer control is similar to that of a triode.
Andrei G Fedorov - One of the best experts on this subject based on the ideXlab platform.
-
Radiation Heat Transfer analysis of the monolith type solid oxide fuel cell
Journal of Power Sources, 2003Co-Authors: Sunil Murthy, Andrei G FedorovAbstract:Abstract In this study, a modeling framework for Heat and mass transport is established for a unit monolith type SOFC, with emphasis on quantifying the Radiation Heat Transfer effects. The Schuster–Schwartzchild two-flux approximation is used for treating thermal Radiation transport in the optically thin yttria-stabilized-zirconia (YSZ) electrolyte, and the Rosseland radiative thermal conductivity is used to account for Radiation effects in the optically thick Ni–YSZ and LSM electrodes. The thermal Radiation Heat Transfer is coupled to the overall energy conservation equations through the divergence of the local radiative flux. Commercially available FLUENT™ CFD software was used as a platform for the global thermal-fluid modeling of the SOFC and the Radiation models were implemented through the user-defined functions. Results from sample calculations show significant changes in the operating temperatures and parameters of the SOFC with the inclusion of Radiation effects.
-
Radiation Heat Transfer analysis of the monolith type solid oxide fuel cell
ASME 2003 International Mechanical Engineering Congress and Exposition, 2003Co-Authors: Sunil Murthy, Andrei G FedorovAbstract:In this study, a modeling framework for Heat and mass transport is investigated for a unit cell of the monolith type SOFC, with emphasis on quantifying the Radiation Heat Transfer effects. The Schuster-Schwartzchild two-flux approximation is used for treating thermal Radiation transport in the optically thin YSZ electrolyte, and the Rosseland radiative thermal conductivity is used to account for Radiation effects in the optically thick Ni-YSZ and LSM electrodes. The thermal Radiation Heat Transfer is coupled to the overall energy conservation equations through the divergence of the local radiative flux. A commercially available CFD software was used as a platform for the global thermal-fluid modeling of the SOFC and the Radiation models were implemented through the user-defined functions. Results from sample calculations show significant changes in the operating temperatures and parameters of the SOFC with the inclusion of Radiation effects.Copyright © 2003 by ASME
M. Petrick - One of the best experts on this subject based on the ideXlab platform.
-
Investigation of spectral Radiation Heat Transfer and NO{sub x} emission in a glass furnace
2000Co-Authors: B. Golchert, C.q. Zhou, S-l Chang, M. PetrickAbstract: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., CO{sub 2}, H{sub 2}O, 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.
-
The effect of the number of wavebands used in spectral Radiation Heat Transfer calculations
2000Co-Authors: S-l Chang, B. Golchert, M. PetrickAbstract:A spectral Radiation Heat Transfer model that conserves emitted and absorbed energy has been developed and used to model the combustion space of an industrial glass furnace. This comprehensive Radiation Heat Transfer model coupled with a computational fluid dynamics (CFD) code was used to investigate the effect of spectral dependencies on the computed results. The results of this work clearly indicate the need for a spectral approach as opposed to a gray body approach since the gray body approach (one waveband) severely underestimates the energy emitted via Radiation.
Prabir Basu - One of the best experts on this subject based on the ideXlab platform.
-
Estimation of the Effect of System Pressure and CO2 Concentration on Radiation Heat Transfer in a Pressurized Circulating Fluidized Bed Combustor
Chemical Engineering Research & Design, 2002Co-Authors: B.v. Reddy, Prabir BasuAbstract:The present work reports the effect of CO2 concentration and system pressure on Radiation Heat Transfer in a pressurized circulating fluidized combustor. The basic Heat Transfer mechanism in a pressurized circulating fluidized bed combustor is presented. For a given CO2 concentration in a pressurized circulating fluidized bed combustor, Radiation Heat Transfer increases slightly with system pressure due to increased gas partial pressure and gas emissivity. The results demonstrate that for the given CO2 concentration, the effect of system pressure on Radiation Heat Transfer is minimal in a pressurized circulating fluidized bed (PCFB) combustor. The effect of variation in CO2 concentration levels on bed to wall Radiation Heat Transfer during combustion in a pressurized circulating fluidized combustor is not significant for a narrow combuster.
