论文标题
使用随机森林进行动态子模型分配的数据辅助燃烧模拟
Data-assisted combustion simulations with dynamic submodel assignment using random forests
论文作者
论文摘要
在这项调查中,我们概述了一种数据辅助方法,该方法在湍流燃烧模拟中采用随机的森林分类器来用于局部和动态燃烧子模型。该方法应用于单元素GOX/GCH4火箭燃烧器的模拟中;进行了先验和后验评估,以(i)评估分类器针对不同量的利益(QOIS)(QOIS)的准确性和可调性,以及(ii)评估由数据辅助燃烧模型分配产生的改进,以预测模拟运行期间的目标QOIS。一项先验研究的结果表明,以局部流量特性为输入变量和燃烧模型误差作为训练标签,分配三种不同的燃烧模型 - 有限速率化学(FRC),火焰进度变量(FPV)模型(FPV)模型(IM) - 甚至具有合理的分类性能,甚至在靶向多个QOIS时,都会分配三种不同的燃烧模型,即训练标签。在后验研究中的应用表明,与单片FPV计算相比,在温度和CO质量分数中,数据辅助模拟的预测得到了改善。这些结果表明,该数据驱动的框架对反应流仿真中的动态燃烧子模型分配有望。
In this investigation, we outline a data-assisted approach that employs random forest classifiers for local and dynamic combustion submodel assignment in turbulent-combustion simulations. This method is applied in simulations of a single-element GOX/GCH4 rocket combustor; a priori as well as a posteriori assessments are conducted to (i) evaluate the accuracy and adjustability of the classifier for targeting different quantities-of-interest (QoIs), and (ii) assess improvements, resulting from the data-assisted combustion model assignment, in predicting target QoIs during simulation runtime. Results from the a priori study show that random forests, trained with local flow properties as input variables and combustion model errors as training labels, assign three different combustion models - finite-rate chemistry (FRC), flamelet progress variable (FPV) model, and inert mixing (IM) - with reasonable classification performance even when targeting multiple QoIs. Applications in a posteriori studies demonstrate improved predictions from data-assisted simulations, in temperature and CO mass fraction, when compared with monolithic FPV calculations. These results demonstrate that this data-driven framework holds promise for the dynamic combustion submodel assignment in reacting flow simulations.