Global and local response of premixed flames during flamevortex interactions under distinct configurations

In turbulent premixed combustion systems, flame surfaces are continuously distorted, extended, generated, and suppressed by vortical eddies over a wide range of turbulence scales in response to the turbulence structures within the flow. However, the complexity of turbulence-flame interactions can obscure fundamental dynamics, so for fundamental insight into this complexity, we study, in detail, flame response to well-defined eddy structures as a function of relative scale and intensity. Specifically, 2D and 3D global and local flame response during vortex-flame interactions with distinct vortex configurations is examined. Flame response to 3 vortex configurations with increasing levels of complexity, but with similar length and velocity scales, are analyzed and compared: a 2D vortex pair, a 2D array of vortices, and a 3D array of vortex rings. The impact of flow configuration on premixed flame evolution is quantified through the resulting flame wrinkling, burning speed, curvature, strain-rate, total stretch rate, burning rate, and flame-turbulence structure. Transient and three-dimensional response, as well as the appropriateness of each vortex configuration to represent turbulence-flame interactions, is analyzed. It is found that the magnitude and time history of flame perturbation are significantly different between interactions with vortex arrays and single vortex pairs.