Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
RADIATION CALCULATIONS ON FLUENT CFD: THREE APPROACHES FOR THE WEIGHTED-SUM-OF-GRAY-GASES MODEL
Submission Author:
Luís Gustavo Pires Rodrigues , RS , Brazil
Co-Authors:
Luís Gustavo Pires Rodrigues, Aline Ziemniczak, Francis França
Presenter: Luís Gustavo Pires Rodrigues
doi://10.26678/ABCM.COBEM2017.COB17-2928
Abstract
Three approaches for the weighted-sum-of-gray-gases (WSGG) model were implemented with the software ANSYS/Fluent to predict radiation heat transfer for a laminar non-premixed methane/air flame: (i) Fluent standard WSGG model; (ii) WSGG for mixtures of CO2 and H2O with constant partial pressure ratio; and (iii) WSGG for arbitrary H2O/CO2 ratios. The fully coupled reactive flow/radiation transport equations problem was solved with the approach (ii) and the converged fields were used for the solution with the remaining methodologies. The fuel is diluted with N2 in order to suppress soot formation, neglected in the solution. User-defined functions (UDF) were developed for the coupling of the WSGG (ii) and (iii) with ANSYS/Fluent. Results for the radiative heat flux were compared with experimental data and the methodologies (ii) and (iii) showed much better accuracy than approach (i). The methodology for non-constant ratio (iii) presented the most reliable results, followed by the WSGG for constant partial pressure ratio. As a way of understanding the Fluent WSGG calculation procedure, a UDF was written and some 1D isothermal/non-isothermal, homogeneous/non-homogeneous test cases were solved. Fluent WSGG is not recommended when good accuracy is required in the solution.
Keywords
radiative transfer, weighted-sum-of-gray-gases, Combustion, ANSYS/Fluent
