Skeletal model reduction with forced optimally time dependent modes
Skeletal model reduction with forced optimally time dependent modes
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DOI：
10.1016/j.combustflame.2021.111684
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
A. Nouri;H. Babaee;P. Givi;H. Chelliah;D. Livescu
中科院分区：
文献类型：
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作者：
A. Nouri;H. Babaee;P. Givi;H. Chelliah;D. Livescu
提出了基于时变系统局部灵敏度分析的骨架模型简化方法，其中灵敏度模型采用强制最优时变模态（f-OTD）建模。f-OTD将灵敏度系数矩阵分解为压缩格式，即两个瘦矩阵的乘积。f-OTD模式和f-OTD系数。这些模式创建了一个低维的、时间相关的、标准正交的基，它捕获了与大多数主导灵敏度相关的相空间的方向。这些方向突出了瞬时活性物质和反应路径。推导了f-OTD模态和系数的演化方程，并描述了f-OTD在骨架还原中的实现。为验证这一点，对零维反应器中乙炔-空气恒压燃烧过程进行了骨架还原，生成了新的骨架还原模型。将模型预测的层流火焰速度、点火延迟和消光曲线与文献中已有的骨架模型进行了比较。结果表明，f-OTD能够系统、高效、准确地去除不重要的反应和物质。
Skeletal model reduction based on local sensitivity analysis of time dependent systems is presented in which sensitivities are modeled by forced optimally time dependent (f-OTD) modes. The f-OTD factorizes the sensitivity coefficient matrix into a compressed format as the product of two skinny matrices,i.e.f-OTD modes and f-OTD coefficients. The modes create a low-dimensional, time dependent, orthonormal basis which capture the directions of the phase space associated with most dominant sensitivities. These directions highlight the instantaneous active species, and reaction paths. Evolution equations for the f-OTD modes and coefficients are derived, and the implementation of f-OTD for skeletal reduction is described. For demonstration, skeletal reduction is conducted of the constant pressure ethylene-air burning in a zero-dimensional reactor, and new reduced models are generated. The laminar flame speed, the ignition delay, and the extinction curve as predicted by the models are compared against some existing skeletal models in literature for the same detailed model. The results demonstrate the capability of f-OTD to eliminate unimportant reactions and species in a systematic, efficient and accurate manner.