arXivDaily arXiv每日学术速递 周一至周五更新
看起来今天可以划水了
arXiv 2407.03055physics.flu-dyn
收藏

采用大涡模拟与动态模态分解研究甲烷-氧气燃烧室中喷注器耦合燃烧动力学

Investigation of injector-coupled combustion dynamics in a methane-oxygen combustor using large eddy simulation and dynamic mode decomposition

Abhishek Sharma, Ashoke De, Sunil Kumar

AI总结:

本文利用大涡模拟与动态模态分解研究甲烷-氧气燃烧室中喷注器-燃烧室频率耦合对热声不稳定的影响,并在CVRC和多元件燃烧室中识别关键声学模态,证明该方法可有效确定燃烧不稳定性的主要成因。

摘要:

本文利用反应流大涡模拟(LES)和分解技术研究甲烷-氧气燃烧室中的燃烧不稳定性。本研究考察了两种工况,以阐明喷注器-燃烧室频率耦合作为热声不稳定成因的重要性。首先在一个众所周知的连续可变共振燃烧室(CVRC)基准案例中进行研究,报告了潜在的不稳定性机制以及喷注器-燃烧室频率耦合在热声不稳定中的作用。随后,多元件火箭燃烧室案例研究识别了关键共振模态,并突出了喷注器与燃烧室区域之间可能存在的频率耦合。氧化剂后段中的纵向压力振荡与燃烧室中的横向压力波之间的相互作用是导致燃烧室中压力动力学增强的原因。本研究使用动态模态分解(DMD)技术揭示CVRC和多元件燃烧室中喷注器与燃烧室内声学模态的演化。通过DMD分析发现的主导压力模态形式也展示了喷注器-燃烧室频率耦合在放大的燃烧动力学中的作用。结果表明,利用高保真LES框架结合模态分解技术,可以有效地确定火箭燃烧室中燃烧不稳定性的主要原因。

英文摘要:

This paper uses a reactive flow large eddy simulation (LES) and decomposition techniques to study combustion instabilities in a methane-oxygen combustor. This work examines two case scenarios to elucidate the significance of injector-chamber frequency coupling as the cause of thermo-acoustic instability. Initial investigation in a well-known benchmark case of the continuously variable resonance combustor (CVRC) reports the potential instability mechanisms and the role of injector-chamber frequency coupling in thermo-acoustic instability. Subsequently, the multi-element rocket combustor case study identifies the critical resonant modes and highlights potential frequency coupling between the injector and the chamber region. The interplay between longitudinal pressure oscillations in the oxidizer post and transverse pressure waves in the chamber is responsible for the enhanced pressure dynamics in the combustor. The present work uses the dynamic mode decomposition (DMD) technique to reveal the evolution of acoustic modes in injector and chamber for CVRC and multi-element combustor. The dominant pressure mode forms found by DMD analysis also showcase the role of injector-chamber frequency coupling in amplified combustion dynamics. The results demonstrate how the predominant cause of combustion instability in rocket combustors can be effectively determined using the high-fidelity LES framework in conjunction with the modal decomposition technique.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑