Computational Fluid Dynamics (CFD), through high-performance computing and robust codes, has proven to be an invaluable tool for the simulation of combustion processes, ranging from low speeddiffusive flames up to detonations. This work intends to provide a review of details needed in modeling asReynolds-averaged Navier–Stokes (RANS), large eddy simulation (LES) or Detached eddy simulation (DES)energy equation in CFD codes used for solving chemically reacting turbulent flows. When the density is variable, traditional Reynolds averages introduce many open correlations between any quantity f and density fluctuations which are difficult to close. Therefore, Favre’s mass-weighted average technique must be preferred.