Premixed Turbulent Combustion Models for Large Eddy and RANS Simulations
Premixed Turbulent Combustion Models for Large Eddy and RANS Simulations
复制标题
用于大涡和 RANS 模拟的预混合湍流燃烧模型
DOI：
10.1115/gt2010-22298
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发表时间：
2010
期刊：
影响因子：
8.7
通讯作者：
M. Pfitzner
中科院分区：
文献类型：
--
作者：
E. Tangermann;R. Keppeler;M. Pfitzner
大涡模拟（LES）已成为计算流体力学的重要工具，但还远远不能取代雷诺平均纳维-斯托克斯（RANS）方法。本研究比较了基于相同物理假设的LES和RANS的燃烧模型。因此，可以直接比较两种方法对燃烧流的结果。该模型基于火焰表面分形的假设，从而得到了RANS中的Lindstedt-Vaos模型。这里给出了它对LES的推广。RANS和LES模型都用湍流本生火焰的数据进行了验证，以评估它们对湍流水平和长度尺度的敏感性。预测的湍流燃烧速度在两个模型中表现出非常相似的行为。这些模型还用第二种验证配置进行了测试，即燃烧流经过一个向后的台阶。该流动清楚地显示了RANS和LES方法在包含大型相干湍流结构的非定常流中的不同行为。ASME版权所有©2010
Large-Eddy simulation (LES) has become an important tool in computational fluid mechanics but still is far from replacing Reynolds-averaged Navier-Stokes (RANS) approaches. The present work compares combustion models for LES and RANS derived from the same physical assumptions. Thus a direct comparison of results from both approaches for a combusting flow becomes possible. The models are based on the assumption of a fractal shape of the flame surface, leading to the Lindstedt-Vaos model in RANS. Its generalization to LES is presented here. Both RANS and LES models are validated with data from a turbulent Bunsen flame to evaluate their sensitivity to turbulence level and length scale. The predicted turbulent burning velocity shows a very similar behavior in both models. The models are also tested with a second validation configuration, the combusting flow over a backward-facing step. This flow clearly shows the different behavior of RANS and LES methods in unsteady flows containing large coherent turbulent structures.Copyright © 2010 by ASME