Simulation of a high Reynolds number reactive transverse jet and the formation of a triple flame

Abstract

This paper briefly describes a hybrid Eulerian–Lagrangian approach for the numerical simulation of turbulent combustion and its application to the study of transverse reactive jets. Because of their interesting mixing properties, transverse jets are important to a variety of industrial applications such as film cooling, primary or dilution jets in gas turbines, and flame stabilization in high speed combustion. To capture the jet complex structure and the associated reaction dynamics, we developed a fast, multiscale and parallel 3D code using a Lagrangian particle method to solve the vorticity transport equation and an Eulerian adaptive grid-based method to solve the reactive transport equations.Flame anchoring computations were done for a pure methane jet in a crossflow of air at a Reynolds number Re=1000 and at a velocity ratio of 5 between the jet and the crossflow velocity. The results show that the reactive jet structure strongly resembles that of the non-reactive case, although the reactive jet is slower to bend into the cross flow and it is wider in the spanwise direction. The flame is anchored downstream of the nozzle in a relatively low velocity region and shows a triple flame structure. This triple flame seats in a region of relatively low scalar dissipation rate. We describe the three dimensional topology of the triple flame, as well as the impact of the jet counter-rotating vortex pair (CVP) on the flame front.