Flow features induced by thermo-diffusive instability: comparison between two-dimensional and three-dimensional flames

Hydrogen-based fuel burning as a substitute for carbon-free fuel has some unique challenges. Intrinsic premixed- flame instabilities can dramatically change the morphological flame characteristics. In the present study, a well- established two-dimensional direct numerical simulation (DNS) data set of intrinsic flame instabilities is compared to a new three-dimensional simulation that uses the same low-Mach formulation in conjunction with a sub-unity Lewis number, deficient reactant thermochemistry approach. While the consumption speed of the 2D flames is observed to increase with the flame domain, the 3D version of the smallest 2D case exhibits a consumption speed 2.5 times its 2D equivalent and 10% higher than the largest 2D flame. Also, upon comparing the reaction rate, the 2D flames showed a 30% reduction compared to the 3D case.