The effect of turbulent mixing and differential diffusion on the autoignition delay of a H_2/N_2 jet flame in vitiated coflow is investigated using the Linear Eddy Model. A broad range of turbulent Reynolds numbers is investigated. It is found that differential diffusion simulations always ignite faster than the equal diffusivity computations. The difference between the two transport models diminishes with increasing the turbulence intensity. The autoignition of the jet flame demonstrates a high sensitivity to the coflow temperature. The effect of turbulent mixing on the ignition delay is classified in two regimes depending on the autoignition delay and the turbulent time scale.
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