Flow-frequency effect upon Huygens front propagation

A premixed flame within a turbulent flow exhibits a decreasing enhancement of fuel consumption rate with increasing turbulence intensity, an effect known as the bending effect. Denet has shown that flow time correlations may be one cause of the bending effect. Using a Damköhler-Huygens front propagation model, we illustrate that the removal of flow components with reduced frequencies greater than unity (ω >kS _L) causes a small reduction in front area but a large reduction in the flow intensity, which is the bending effect (ω is the frequency and k is the wavenumber). To be effective in producing front area, a flow mode must have a phase velocity, ω/k, smaller than the laminar burning velocity, S _L.