Confinement-Induced Instabilities in a Jet-Stabilized Gas Turbine Model Combustor

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• 作者：Zhiyao Yin ; Isaac Boxx ; Michael Stöhr ; Oliver Lammel…
• 关键词：Confined turbulent flames ; Jet stabilized flames ; Jet oscillation ; Highspeed diagnostics ; Proper orthogonal decomposition
• 刊名：Flow, Turbulence and Combustion
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：98
• 期：1
• 页码：217-235
• 全文大小：
• 刊物类别：Engineering
• 刊物主题：Engineering Fluid Dynamics; Fluid- and Aerodynamics; Engineering Thermodynamics, Heat and Mass Transfer; Automotive Engineering;
• 出版者：Springer Netherlands
• ISSN：1573-1987
• 卷排序：98

文摘

Self-sustained jet flapping is observed in a confined, premixed and preheated methane-air turbulent flame, generated in a single-nozzle jet-stabilized gas turbine model combustor designed based on the FLOXⓇ concept. The flapping frequency and its complex motion within the confinement of the combustor are characterized in detail using proper orthogonal decomposition (POD) of the flow fields measured by particle imaging velocimetry (PIV). The influence of jet flapping on combustion stability is examined using simultaneous PIV/OH chemiluminescence imaging and PIV/planar laser-induced fluorescence of OH radicals (OH PLIF) at 5 kHz repetition rate. By influencing the size and location of the recirculation zones, jet flapping modifies the flame shape and flame lift-off height. It also controls the amount of hot gas entrainment into the recirculation zones. In extreme cases, jet flapping is found to cause temporary local extinction of the flame, due to jet impingement on the combustor wall and partial blockage of burned gas entrainment. The flame is only able to recover after the jet detaches from the wall and reopens the back flow channel. The results suggest that jet flapping could play a key role in the stabilization mechanisms in similar jet-stabilized combustors.