Large-eddy simulation and challenges for projection-based reduced-order modeling of a gas turbine model combustor
Large-eddy simulation and challenges for projection-based reduced-order modeling of a gas turbine model combustor
复制标题
DOI：
10.1177/17568277221100650
复制
发表时间：
2022-03
影响因子：
1.6
通讯作者：
Nicholas Arnold-Medabalimi;Cheng Huang;K. Duraisamy
中科院分区：
文献类型：
--
作者：
Nicholas Arnold-Medabalimi;Cheng Huang;K. Duraisamy
由于燃气轮机燃烧的多尺度物理混沌以及声学、流体力学和化学过程之间复杂的非线性相互作用，对燃气轮机燃烧的计算效率建模是具有挑战性的。采用基于火焰面的方法对具有湍流燃烧效应的燃气轮机模型燃烧室进行了大涡模拟，称为全阶模型(FOM)。振型分析显示了与平均和瞬时高频粒子图像测速场的高度相关性。利用动态模式分解对进动涡核的动力学特性进行了定量表征。将FOM的控制方程投影到低维线性流形上，构造降维模型。采用离散一致的最小二乘投影来保证全局稳定性。只读存储器提供了训练区域内燃烧动力学的准确重建，但在未来的状态预测中面临着巨大的挑战。这一限制主要是由于投影误差的增加，这反过来又是涉及广泛分散的相干结构的高度混沌的流场的直接结果。使用自适应基本方法克服了这一缺点，该方法产生与FOM一致的训练区域之外的动态的准确预测。正式的基于投影的ROMS还没有被应用于这种规模和复杂的问题，而获得准确和高效的ROMS是一个巨大的挑战问题。一种可用于生产的只读存储器方法将显著降低火焰动力学的计算成本以及该预测在较小规模的计算机上的可移植性。
Computationally efficient modeling of gas turbine combustion is challenging due to the chaotic multi-scale physics and the complex non-linear interactions between acoustic, hydrodynamic, and chemical processes. A large-eddy simulation, referred to as the full order model (FOM), is performed for a gas turbine model combustor with turbulent combustion effects modeled using a flamelet-based method. Modal analysis reveals a high degree of correlation with averaged and instantaneous high-frequency particle image velocimetry fields. The dynamics of the precessing vortex core is quantitatively characterized using dynamic mode decomposition. The governing equations of the FOM are projected onto a low-dimensional linear manifold to construct a reduced-order model (ROM). A discretely-consistent least squares projection is used to guarantee global stability. The ROM provides an accurate reconstruction of the combustion dynamics within the training region, but faces a significant challenge in future state predictions. This limitation is mainly due to the increased projection error, which in turn is a direct consequence of the highly chaotic nature of the flow field, involving a wide range of dispersed coherent structures. This shortcoming is overcome using an adaptive basis method which yields accurate predictions of dynamics beyond the training region consistent with the FOM. Formal projection-based ROMs have not been applied to a problem of this scale and complexity, and achieving accurate and efficient ROMs is a grand challenge problem. A production-ready ROM method will significantly decrease the computational cost of the flame dynamics as well as the portability of this prediction to smaller-scale computers.