Importance of Physical Modeling for Simulations of Turbulent Reactive Flows

Abstract

The physical models implemented in practical computational tools are not systematically required for the numerical simulations of turbulent flows. When the grid is sufficiently refined, satisfactory numerical results can be obtained even if the smallest characteristic scales are not solved. However, when reactive flows are considered, the physical mechanisms occurring at the smallest scales may control the main characteristics of the flow such as the flame velocity propagation. Therefore, the development of new physical models is still needed for practical numerical simulations of turbulent reactive flows. A recent work that describes the inner structure of turbulent flames as composed of different layers is presented. This study also evidences the necessity to understand in details the transition between a slow chemistry layers to a fast chemistry layer. The behavior of the scalar variance and turbulent scalar flux between these two limit cases is presented.