Large-eddy simulation of bluff-body stabilized premixed flames with low-dissipative, structure-preserving convection schemes
Large-eddy simulation of bluff-body stabilized premixed flames with low-dissipative, structure-preserving convection schemes
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DOI：
10.1063/5.0155829
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发表时间：
2023-05
期刊：
影响因子：
1.6
通讯作者：
X. Deng;J. Massey;N. Swaminathan
中科院分区：
文献类型：
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作者：
X. Deng;J. Massey;N. Swaminathan
大涡模拟（LES）具有预测现代实际燃烧室中湍流燃烧现象的潜力。由于亚网格模型的误差可能与LES方法中的数值误差相当，因此减轻数值误差的影响与构建精确的亚网格模型一样重要。因此，在本研究中，一个低耗散的，结构保持的ROUND（统一归一化变量图上的重构算子）方案被测试用于反应流的LES。通过模拟一个被动标量的对流扩散过程，评估其精度、中央处理单元成本和结构保持特性，证明了该方案的高效性。利用该格式对两种海崖体稳定火焰进行了数值模拟。对于低湍流强度，本格式提高了瞬时流场和平均流场的数值分辨率。与常规方案相比，ROUND方案还改善了流量统计的预测。此外，ROUND格式比传统格式更好地保持了平均流的轴对称性。对于高湍流强度的情况，ROUND格式避免了非物理的数值振荡。使用该方案获得的流量和火焰统计数据与测量结果比较良好。因此，这项工作表明了使用ROUND计划的反应流LES的优点。
Large eddy simulation (LES) has the potential to predict turbulent combustion phenomena in modern practical combustors. As errors from sub-grid models may be comparable to the numerical errors in the LES approach, mitigating the impact of the numerical errors is as important as constructing accurate sub-grid models. Therefore, a low-dissipative, structure-preserving ROUND (Reconstruction Operators on Unified Normalized-variable Diagram) scheme is tested for the LES of reacting flows in this study. The high efficiency of this scheme is demonstrated by evaluating its accuracy, central processing unit cost, and structure-preserving property by simulating the convection–diffusion process of a passive scalar. Simulations of two bluff body stabilized flames are studied using this scheme. For low turbulence intensity, the current scheme improves the numerical resolution of the instantaneous and averaged flow fields. The prediction of flow statistics is also improved by the ROUND schemes compared to the conventional schemes. Moreover, the ROUND schemes preserve the axisymmetry of the averaged flow better than the conventional schemes for the cases investigated here. For the high turbulence intensity case, the ROUND scheme avoids nonphysical numerical oscillations. The flow and flame statistics obtained using this scheme compare well with measurements. Therefore, this work demonstrates the advantages of using ROUND schemes for LES of reacting flows.