Shock tube experiment on ignition delay times and kinetic modeling study of MMH/O2/N2 mixtures

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.2025.114478

Xuan Ren , Ruining He , Yilin Zhao , Pengzhi Wang , Xin bai , Yang Li

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引用次数: 0

Abstract

Monomethylhydrazine (CH₃NHNH₂ MMH) has been widely used as a propellant for spacecraft and rockets. In this study, the shock tube experiment on ignition delay times (IDTs) and the kinetic modeling study of MMH/O₂/N₂ mixtures are undertaken to improve the understanding of the oxidation and combustion properties of MMH. Ignition delay times are measured in shock tube at pressures of 4, 8, 18 bar in the temperature range of 1250–1500 K, for two equivalence ratios of 1.0 and 2.0 for MMH/O₂/N₂ mixtures. The OH signal indicates that secondary ignition occurs during the ignition of MMH/O₂/N₂ mixtures at lower temperatures. As the ignition temperature rises, the two ignition events gradually evolve into one ignition. The energy of the first ignition is increased due to the high O₂ concentration under the same conditions.

A detailed kinetic model consisting of 1333 reactions and 188 species was developed for the combustion of MMH/O₂/N₂ mixtures. This model, which also includes the MMH decomposition model (Diévart_2020), nitrogen chemistry (Glarborg_2018) and C₀C₂ (C3Mech 4.0_2025) introduced as the core mechanisms. H-atom abstraction, unimolecular decomposition and reactions were also considered as two important classes affecting combustion. Good agreement between measured and simulated IDTs was obtained for MMH/O₂/N₂ mixtures at high temperatures (> 1250 K). Sensitivity and flux analyses were conducted to highlight the key reactions in MMH/O₂/N₂ combustion. MMH is mainly consumed by H-atom abstraction reactions and less by bond dissociation reactions at early ignition stages. cCH₃NHNH and CH₂NHNH₂ radicals also play a crucial role in the ignition of MMH/O₂/N₂, which has been overlooked in the previous model in literature.

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MMH/O2/N2混合物点火延迟时间激波管实验及动力学模型研究

一甲基肼（CH3NHNH2 MMH）被广泛用作航天器和火箭的推进剂。本研究通过激波管点火延迟时间（IDTs）实验和MMH/O2/N2混合物的动力学建模研究来提高对MMH氧化和燃烧特性的认识。在激波管中测量了MMH/O2/N2混合物在温度范围为1250-1500 K、压力为4、8、18 bar时的点火延迟时间，等效比为1.0和2.0。OH信号表明MMH/O2/N2混合物在较低温度下点火时发生二次点火。随着点火温度的升高，两次点火事件逐渐演化为一次点火。在相同条件下，由于氧气浓度高，第一次点火的能量增加。建立了包含1333个反应和188种物质的MMH/O2/N2混合燃烧动力学模型。该模型还包括引入的MMH分解模型（didiesvart_2020）、氮化学（Glarborg_2018）和C0C2 （C3Mech 4.0_2025）作为核心机制。h原子抽离、单分子分解和反应也被认为是影响燃烧的两个重要类别。在高温（> 1250 K）下，MMH/O2/N2混合物的idt测量值与模拟值吻合良好。通过灵敏度和通量分析，突出了MMH/O2/N2燃烧过程中的关键反应。在点火初期，MMH主要被h原子抽离反应消耗，键解反应消耗较少。cCH3NHNH和CH2NHNH2自由基在MMH/O2/N2的点火中也起着至关重要的作用，这一点在之前的文献模型中被忽略了。

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.