title: Facilitated ignition in turbulence through differential diffusion.
abstract: Contrary to the belief that ignition of a combustible mixture by a high-energy kernel is more difficult in turbulence than in quiescence because of the increased dissipation rate of the deposited energy, we experimentally demonstrate that it can actually be facilitated by turbulence for mixtures whose thermal diffusivity sufficiently exceeds its mass diffusivity. In such cases, turbulence breaks the otherwise single spherical flame of positive curvature, and hence positive aerodynamics stretch, into a multitude of wrinkled flamelets subjected to either positive or negative stretch, such that the intensified burning of the latter constitutes local sources to facilitate ignition.
authors: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors: Fujia
authors: F
authors: Wu
authors: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors: Abhishek
authors: A
authors: Saha
authors: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors: Swetaprovo
authors: S
authors: Chaudhuri
authors: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA and Center for Combustion Energy, Tsinghua University, Beijing 100084, China.
authors: Chung K
authors: CK
authors: Law