Japan Aerospace Exploration Agency Computational Science Research Group, Institute of Aerospace Technology
Japan Aerospace Exploration Agency Computational Science Research Group, Institute of Aerospace Technology
Japan Aerospace Exploration Agency Computational Science Research Group, Institute of Aerospace Technology
Japan Aerospace Exploration Agency Computational Science Research Group, Institute of Aerospace Technology
Japan Aerospace Exploration Agency Computational Science Research Group, Institute of Aerospace Technology
A real-size hydrogen jet lifted flame is successfully reproduced by a highly resolved time-dependent 3-D numerical simulation with detailed chemistry and rigorous transport properties. The analysis based on Flame Index clearly shows that the lifted flame is not a single flame but consists of three flame elements; (1) a stable leading edge flame, (2) diffusion flame islands floating on the outer side of the lifted flame, (3) inner vigorously turbulent rich premixed flames. The stable laminar leading edge flame of ring shape has a triple flame like structure and is stabilized outside the turbulent jet where the incoming flow almost balances with the burning velocity. The combustion in diffusion flame islands can be explained by the conventional laminar flamelet concept, although they take island-like shapes. The island-like shapes are produced by the unsteady turbulent behavior of inner rich premixed flame. In the inner vigorously turbulent rich premixed flames, flame structures that are largely deviated from the laminar flamelet concept are observed. The turbulence scales and the flame structure scales are in the same order and turbulent eddies can easily penetrate into the flame internal structures.
詳細シミュレーションによる水素噴流浮き上がり火炎の構造解析
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