Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
CFD modelling of Delft III Flame under acoustic forcing
Submission Author:
Rígel Alves , BA
Co-Authors:
Alex Álisson Bandeira Santos, Rígel Alves
Presenter: Alex Álisson Bandeira Santos
doi://10.26678/ABCM.COBEM2017.COB17-0566
Abstract
This article will attempt to investigate acoustic forcing in ‘Delft Flame III’ – a turbulent, pilot-stabilized, diffusive, non-luminous, natural gas flame – using Ansys Fluent. Geometry is modelled as a two-dimensional, axisymmetric, structured Cartesian mesh; pilot holes’ influence is neglected. Reynolds Stress is used as turbulence model, Discrete Ordinates as radiation model and Weighted Sum of Grey Gases for the absorption coefficient calculation. Inlet fuel is simplified as comprised solely of methane and molecular nitrogen, whose compositions are adjusted as to preserve the original calorific value of the Dutch natural gas; far field is modelled as symmetry and outlet as zero-gauge pressure (with standard air at ambient conditions set as backflow configuration). Three chemical mechanisms are used and compared: GRI 3.0, UCSD 2016-12-14 and Narayanaswamy et. al. 2014.; results obtained were equivalent, except for NO mass fraction and for the soot volume fraction. Similarly, two combustion models were tested: Steady and Unsteady Laminar Flamelet; the former was sufficient to reach converged results for all variables involved (apart from H2 and CO mass fractions), however the latter decreased the accuracy of NO and soot results. Finally, the software revealed to be uncappable of running a transient analysis from the steady-state, converged solution.
Keywords
Delft Flame III, Computational fluid dynamics (CFD), Combustion, acoustic forcing
