Compliance of combustion models for turbulent reacting flow simulations
Compliance of combustion models for turbulent reacting flow simulations
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DOI：
10.1016/j.fuel.2016.07.074
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发表时间：
2016-12
期刊：
影响因子：
7.4
通讯作者：
Hao Wu;M. Ihme
中科院分区：
文献类型：
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作者：
Hao Wu;M. Ihme
利用低维歧管燃烧模型的大涡模拟（LES）的湍流反应流引入模型简化，代表来源的不确定性，除了所产生的湍流封闭模型和数值离散。在没有测量或参考结果的情况下定量评估这些不确定性的能力对于实际燃烧装置的可靠和预测性模拟至关重要。本文关注的是延伸themanifold漂移term LES检查遵守一个特定的燃烧模型在描述一个感兴趣的数量（QoI）相对于底层流场表示。这个漂移项以前被引入作为帕累托有效燃烧（PEC）框架的一个关键组成部分。漂移项的行为在一系列的测试案例中进行了检查。为此，大涡模拟的部分预混湍流先导火焰与不均匀的进口流，其中非预混小火焰/进度变量（FPV）模型和预混过滤表列化学LES（F-TACLES）制定。漂移项被证明是能够识别化学敏感区域相对于用户特定的生活质量。由此，通过计算不同燃烧模型的漂移项的相对大小，得到了一种特定的燃烧状态指标。与常用的火焰指标的比较表明，火焰指数和其他指标，仅仅是基于主要物种和火焰拓扑结构是不够的，在描述复杂的物理过程中，多制度燃烧。
The utilization of low-dimensional manifold combustion models for large-eddy simulation (LES) of turbulent reactive flows introduces model simplifications that represent sources of uncertainties in addition to those arising from turbulent closure models and numerical discretization. The ability to quantitatively assess these uncertainties in the absence of measurements or reference results is vital for reliable and predictive simulations of practical combustion devices. This paper is concerned with the extension of themanifold drift termto LES to examine the compliance of a particular combustion model in describing a quantity of interest (QoI) with respect to the underlying flow-field representation. This drift term was previously introduced as a key component of the Pareto-efficient combustion (PEC) framework. The behavior of the drift term is examined in a series of test cases. To this end, large-eddy simulations of a partially-premixed turbulent pilot flame with inhomogeneous inlet streams are performed, in which the non-premixed flamelet/progress-variable (FPV) model and the premixed filtered tabulated chemistry LES (F-TACLES) formulation are employed. The drift term is shown to be capable of identifying chemically sensitive regions with respect to user-specific QoIs. With this, a species-specific combustion regime indicator is derived by computing the relative magnitude of the drift terms for different combustion models. Comparisons with commonly employed flame indicators suggests that the flame index and other indicators that are solely based on major species and flame topology are insufficient in describing complex physical processes in multi-regime combustion.