Sensitivity of swirling flows to small changes in the swirler geometry
Sensitivity of swirling flows to small changes in the swirler geometry
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DOI：
10.1016/j.crme.2012.10.018
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发表时间：
2013
影响因子：
0.8
通讯作者：
Jean-François Bourgouin;J. Moeck;D. Durox;T. Schuller;S. Candel
中科院分区：
文献类型：
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作者：
Jean-François Bourgouin;J. Moeck;D. Durox;T. Schuller;S. Candel
旋流器设计强烈影响燃气轮机的燃烧稳定性和火焰动力学。旋流器引起的旋转流主要由旋流数决定。虽然经验公式可用于估计该量并推论相应的流动特征，但无法精确量化几何细节的影响。本文通过分析平均流场和非定常结构对旋流器设计微小变化的敏感性来研究这个问题。通过结合大涡模拟和实验，对两个几何形状略有不同的径向旋流器进行了比较。几何差异引起喷射平面附近平均速度分量的变化，从而改变内部再循环区的结构。然后通过对数值结果应用动态模式分解来揭示对进动涡核的影响。研究发现，旋流器的几何修改显着影响流动结构和 PVC 频率。
Swirler design strongly influences combustion stabilization and flame dynamics in gas turbines. The rotating flow induced by the swirler is mainly determined by the swirl number. While empirical formulas may be used to estimate this quantity and deduce the corresponding flow features, a precise quantification of the impact of geometrical details is not available. This issue is investigated in this article by analyzing the sensitivity of the mean flow field and unsteady structures to small changes in the swirler design. Two radial swirlers, with slightly different geometries are compared by combining Large Eddy Simulations and experiments. The geometrical difference induces changes of the mean velocity components near the injection plane, which in turn modify the structure of the internal recirculation zone. Effects on the precessing vortex core are then revealed by applying a dynamic mode decomposition to the numerical results. It is found that the geometrical modification of the swirler notably affects the flow structure and PVC frequency.