Large-eddy simulation of a turbulent bluff-body stabilized flame using the Bernstein Decomposition Conditional Source-Term Estimation model

IF 6.2 2区工程技术 Q2 ENERGY & FUELS

Combustion and Flame Pub Date : 2025-09-18 DOI:10.1016/j.combustflame.2025.114449

Peyman Haghighi Tajvar, M. Mahdi Salehi

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引用次数: 0

Abstract

Originating from the Conditional Moment Closure (CMC), the Conditional Source-Term Estimation (CSE) is a model for predicting the interaction between turbulence and chemistry. Compared to CMC, CSE offers reduced computational cost and implementation complexities by solving an integral equation to obtain the conditional scalars. This paper applies a modified version of CSE, termed Bernstein Decomposition Conditional Source-Term Estimation (BDCSE), which results in additional savings in terms of numerical effort compared to the traditional CSE method. The BDCSE approach also provides a more robust regularization of the ill-posed integral equation. In this work, the BDCSE model is integrated into a Large Eddy Simulation (LES) framework and employed to simulate an experimental-scale combustor with a bluff-body burner operating in a lean premixed regime. Two flames with inlet turbulence intensities of 2% and 22% are simulated. Results demonstrate that BDCSE effectively predicts temperature and velocity fields, as well as minor and major species concentrations, highlighting its strong potential for turbulent combustion modeling.

Novelty and Significance

This work contributes to turbulent combustion modeling by advancing the Bernstein Decomposition Conditional Source-Term Estimation (BDCSE) model in two important ways. First, BDCSE, a modified variant of the Conditional Source-Term Estimation (CSE) approach, is extended from Reynolds-Averaged Navier–Stokes (RANS) framework to Large Eddy Simulation (LES). Second, unlike previous studies, BDCSE is applied to a realistic combustion environment—a confined, premixed combustion chamber. The model’s ability to accurately predict temperature, velocity and species distributions under both low and high turbulence intensities demonstrates its robustness and applicability to real-life industrial applications. These developments support the use of BDCSE in predictive tools for designing combustion systems.

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基于Bernstein分解条件源项估计模型的湍流崖体稳定火焰大涡模拟

条件源项估计（CSE）是一种预测湍流与化学相互作用的模型，起源于条件矩闭（CMC）。与CMC相比，CSE通过求解积分方程来获得条件标量，从而降低了计算成本和实现复杂性。本文应用了一种改进的CSE，称为Bernstein分解条件源项估计（BDCSE），与传统的CSE方法相比，它在数值方面节省了额外的工作量。BDCSE方法还提供了不适定积分方程的更鲁棒的正则化。在这项工作中，BDCSE模型被集成到一个大涡模拟（LES）框架中，并用于模拟一个实验规模的燃烧室，该燃烧室具有在精益预混状态下运行的钝体燃烧器。模拟了进口湍流度分别为2%和22%的两种火焰。结果表明，BDCSE能有效地预测温度场和速度场，以及次要和主要物质浓度，突出了其在湍流燃烧模拟中的强大潜力。本研究在两个重要方面改进了Bernstein分解条件源项估计（BDCSE）模型，为湍流燃烧建模做出了贡献。首先，将条件源项估计（CSE）方法的改进版本BDCSE从reynolds - average Navier-Stokes （RANS）框架扩展到大涡模拟（LES）。其次，与以往的研究不同，BDCSE应用于真实的燃烧环境-密闭的预混燃烧室。该模型在低湍流强度和高湍流强度下都能准确预测温度、速度和物种分布，这证明了它的鲁棒性和对实际工业应用的适用性。这些进展支持了在设计燃烧系统的预测工具中使用BDCSE。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Combustion and Flame 工程技术-工程：化工

CiteScore

9.50

自引率

20.50%

发文量

631

审稿时长

3.8 months

期刊介绍： The mission of the journal is to publish high quality work from experimental, theoretical, and computational investigations on the fundamentals of combustion phenomena and closely allied matters. While submissions in all pertinent areas are welcomed, past and recent focus of the journal has been on: Development and validation of reaction kinetics, reduction of reaction mechanisms and modeling of combustion systems, including: Conventional, alternative and surrogate fuels; Pollutants; Particulate and aerosol formation and abatement; Heterogeneous processes. Experimental, theoretical, and computational studies of laminar and turbulent combustion phenomena, including: Premixed and non-premixed flames; Ignition and extinction phenomena; Flame propagation; Flame structure; Instabilities and swirl; Flame spread; Multi-phase reactants. Advances in diagnostic and computational methods in combustion, including: Measurement and simulation of scalar and vector properties; Novel techniques; State-of-the art applications. Fundamental investigations of combustion technologies and systems, including: Internal combustion engines; Gas turbines; Small- and large-scale stationary combustion and power generation; Catalytic combustion; Combustion synthesis; Combustion under extreme conditions; New concepts.