首页>
外文会议>AIAA SciTech forum and exposition
>Bluff-Body Stabilized Flame Simulations using SBES in Combination with the Flamelet Generated Manifold Combustion Model
【24h】
Bluff-Body Stabilized Flame Simulations using SBES in Combination with the Flamelet Generated Manifold Combustion Model
Bluff-body stabilized flames feature several transient flow structures, such as oscillating shear layers, recirculation zones and vortex shedding. These transient characteristics are captured with scale resolving simulations using large eddy simulations (LES), which require an extremely fine grid near the bluff body. This paper focuses on investigating the potential of hybrid RANS/LES turbulence for modeling such problems. In the current work, a hybrid turbulence model is used for modeling bluff-body stabilized premixed propane/air flames. Among the class of hybrid models, a Stress-Blended Eddy Simulation (SBES) approach has been applied using a shielding function approach. The SBES models used in this investigation has blending functions to transition from the RANS-SST model near the walls to the dynamic Smagorinsky LES closure in the core region away from walls. The current SBES model is first validated for non-reacting flow; the reacting flow with SBES is modeled using the Flamelet Generated Manifold model. The blending of manifold inputs, such as scalar dissipation and variances, is accomplished using the same shielding function as above, in a consistent manner. Boundary conditions for both non-reacting and reacting flows, are based on the MVP1 workshop. A grid sensitivity study has been performed using structured grids. The current results are compared with experimental data as well as with the LES computations. For combustion modeling, the manifold is generated from a series of one dimensional freely propagating premixed flames. The chemistry of Propane-Air reactions is modeled using a detailed reaction mechanism from the UC San Diego mechanism consisting of 57 species and 235 reactions. Comparisons with experimental results are performed in the wake of the bluff body for velocity, temperature and CO mass fractions.
展开▼
机译：凹槽体稳定的火焰具有几个瞬态流动结构，例如振荡剪切层，再循环区域和涡旋脱落。使用大型涡流模拟（LES）进行尺度解析模拟，这些瞬态特性捕获，该模拟模拟，该模拟在凹槽主体附近的极其精细的网格。本文侧重于调查杂交rans / les湍流的潜力，以建模这些问题。在当前的工作中，混合动力湍流模型用于造型的虚张体稳定预混丙烷/空气火焰。在混合模型的类中，使用屏蔽功能方法应用了应力混合的涡流模拟（SBE）方法。本研究中使用的SBES模型具有混合函数来从墙壁附近的RANS-SST模型转换到远离墙壁的核心区域中的动态SMAGORINSKY LES关闭。首先验证当前SBES模型以进行非反应流动;利用SBE的反应流动使用燧发物型铸造歧管模型进行建模。歧管输入的混合，例如标量耗散和差异，以与上面的相同的屏蔽功能以一致的方式完成。非反应和反应流动的边界条件基于MVP1车间。使用结构栅格进行了网格敏感性研究。将当前结果与实验数据以及LES计算进行比较。对于燃烧建模，歧管由一系列一维自由传播预混合火焰产生。使用来自57种和235个反应的UC San Diego机制，使用详细的反应机制进行建模丙烷 - 空气反应的化学。具有实验结果的比较在凹槽体之后进行，用于速度，温度和CO质量级分。
展开▼
