Flame propagation through periodic vortices,

The discovery of a new class of Navier-Stokes solutions representing steady periodic stretched vortices [1] offers a useful test-bed for examining interactions between flames and complex flow-fields. After briefly describing these vortex solutions and their wide-ranging parameterisation in terms of wavelength and amplitude, this article examines their effect on flames of constant normal propagation speed as observed through numerical solutions of an eikonal equation. Over certain ranges of vortex amplitude and flame-speed, a corridor of enhanced flame passage is seen to be created as a leading flame-tip manages to leap-frog between successive vortices. However, for large enough amplitudes of vorticity or small enough flame-speeds, the flame fails to be able to benefit from the advection due to the vortices. It is shown that the leading tips of such flames are effectively trapped by the stretched vortices.