A DNS study on the stabilization mechanism of a turbulent lifted ethylene jet flame in highly-heated coflow
Cited 34 times inCited 31 times in
- A DNS study on the stabilization mechanism of a turbulent lifted ethylene jet flame in highly-heated coflow
- Yoo, Chun Sang; Richardson, Edward S.; Sankaran, Ramanan; Chen, Jacqueline H.
- Auto-ignition; Chemical explosive; Co-flow; Direct numerical simulation (DNS); Displacement speed; Grid points; High-speed jet; Jet flames; Key variables; Lagrangian tracking; Large-scale flow structure; Lean mixtures; Lifted flames; Mixture fraction; Near-field; Rapid movements; Reduced mechanisms; Saw-tooth; Scalar dissipation rate; Stabilization mechanisms
- Issue Date
- ELSEVIER SCIENCE INC
- PROCEEDINGS OF THE COMBUSTION INSTITUTE, v.33, no.1, pp.1619 - 1627
- Direct numerical simulation (DNS) of the near-field of a three-dimensional spatially-developing turbulent ethylene jet flame in highly-heated coflow is performed with a reduced mechanism to determine the stabilization mechanism. The DNS was performed at a jet Reynolds number of 10,000 with over 1.29 billion grid points. The results show that auto-ignition in a fuel-lean mixture at the flame base is the main source of stabilization of the lifted jet flame. The Damkohler number and chemical explosive mode (CEM) analysis also verify that auto-ignition occurs at the flame base. In addition to auto-ignition, Lagrangian tracking of the flame base reveals the passage of large-scale flow structures and their correlation with the fluctuations of the flame base similar to a previous study (Yoo et al., J. Fluid Mech. 640 (2009) 453-481) with hydrogen/air jet flames. It is also observed that the present lifted flame base exhibits a cyclic 'saw-tooth' shaped movement marked by rapid movement upstream and slower movement downstream. This is a consequence of the lifted flame being stabilized by a balance between consecutive auto-ignition events in hot fuel-lean mixtures and convection induced by the high-speed jet and coflow velocities. This is confirmed by Lagrangian tracking of key variables including the flame-normal velocity, displacement speed, scalar dissipation rate, and mixture fraction at the stabilization point.
- ; Go to Link
Appears in Collections:
- MNE_Journal Papers
can give you direct access to the published full text of this article. (UNISTARs only)
Show full item record
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.