Fully compressible simulation of low-speed premixed reacting flows

Low speed premixed combustion flows in industrial applications are generally simulated using the "incompressible" Navier-Stokes algorithms, which belong to the family of fractional step methods, or segregated methods. The approximations used for the combustion modelling in the framework of the segregated mathematical formulation, often represent important limitations for applying the combustion numerical simulation to a wider class of problems of engineering interest. Recent developments of preconditioning techniques allow to apply the same complete system of Navier-Stokes equations to a wide variety of fluid flow problems characterized by the whole range of Reynolds, Mach, Grashof, Prandtl and Damkoeler numbers. The present work describes the development of a fully "compressible" mathematical model for the simulation of low-speed turbulent premixed reactive flows. Issues on flow and fluid compressibility as well as on the two mathematical alternative formulations, are discussed. Also discussed are issues related to coupling the flamelet premixed combustion model (based on the solution of a transport equation for the progress variable) with one-equation turbulence models, instead of the classical two-equation $kappa-epsilon$ model. In this work the model by Spalart & Allmaras is used. The several advantages brought about by the use of the fully compressible formulation are discussed based on the results obtained on a test case taken from literature.

@Misc{MT03a,
  author       = {Mulas, M. and Talice, M.},
  title        = {Fully compressible simulation of low-speed premixed reacting flows},
  month        = {june},
  year         = {2003},
  note         = {Conference held in Orlando, FL, USAurl:   idxproject: ?},
  keywords     = {CFD, premixed turbulent combustion},
  url          = {https://publications.crs4.it/pubdocs/2003/MT03a},
}