Coupling tabulated chemistry with compressible CFD solvers

Abstract

This work focuses on the coupling between tabulated chemistry techniques with compressible solvers. In low Mach-number CFD solvers the coupling is straightforward because thermo-chemical quantities are directly read in a thermo-chemical database. However, because of perturbations introduced by acoustics, the coupling with fully compressible Navier–Stokes equations is not straightforward. In order to be consistent with tabulated chemistry framework, a new strategy to predict temperature field from the transported energy is developed. Boundary conditions are reformulated following Navier–Stokes Characteristic Boundary Conditions (NSCBC) formalism. The method called TTC (Tabulated Thermo-chemistry for Compressible flows) is implemented in a compressible CFD code and validated by comparison with multi-component simulations. Temperature computation and characteristic boundary conditions reformulations are first validated on one-dimensional tests. A three-dimensional non-reactive case is then computed by performing a large eddy simulation of a turbulent round jet. Finally, a one-dimensional laminar flame simulation assesses the method performances.