Near-field local flame extinction of oxy-syngas non-premixed jet flames: a DNS study

• Main Authors: Ranga Dinesh, K.K.J (Author), Van Oijen, J.A (Author), Luo, K.H (Author), Jiang, X. (Author)
• Format: Article
• Language: English
• Published: 2014-08-15.
• Subjects: Article
• Online Access: Get fulltext

 An investigation of the local flame extinction of H2/CO oxy-syngas and syngas-air nonpremixed jet flames was carried out using three-dimensional direct numerical simulations (DNS) with detailed chemistry by using flamelet generated manifold chemistry (FGM). The work has two main objectives: identify the influence of the Reynolds number on the oxy-syngas flame structure, and to clarify the local flame extinction of oxy-syngas and syngas-air flames at a higher Reynolds number. Two oxy-syngas flames at Reynolds numbers 3000 and 6000 and one syngas-air flame at Reynolds number 6000 were simulated. The scattered data, probability density function distributions and fully burning probability provide the local flame characteristics of oxy-syngas and syngas-air nonpremixed jet flames. It is found that the H2/CO oxy-syngas flame burns well compared to the syngas-air flame and the high Reynolds number causes more flow straining, resulting in higher scalar dissipation rates which lead to lower temperatures and eventually local flame extinction. The oxy-syngas flames burns more vigorously than the syngas-air flame with the same adiabatic flame temperature of approximately 2400 K.