物理化学学报 >> 2019, Vol. 35 >> Issue (11): 1241-1247.doi: 10.3866/PKU.WHXB201812031

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NOFBX新型绿色推进剂燃烧化学反应动力学模型

郑东1,*(),熊鹏飞2,钟北京3   

  1. 1 西南交通大学机械学院, 成都 610031
    2 中国空气动力研究与发展中心,四川 绵阳 621000
    3 清华大学航天航空学院,北京 100084
  • 收稿日期:2018-12-18 录用日期:2019-01-01 发布日期:2019-02-21
  • 通讯作者: 郑东 E-mail:zhengd11@yeah.net
  • 基金资助:
    国家自然科学基金项目(51606212);中央高校基本科研业务费专项资金项目(2682017CX035)

Chemical Kinetic Model for the Combustion of the Green Propellant of the Nitrous Oxide Fuel Blend

Dong ZHENG1,*(),Pengfei XIONG2,Beijing ZHONG3   

  1. 1 School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, P. R. China
    2 Airbreathing Hypersonic Technology Research Center, China Aerodynamics Research and Development Center, Mianyang 621000, Sichuan Province, P. R. China
    3 School of Aerospace Engineering, Tsinghua University, Beijing 100084, P. R. China
  • Received:2018-12-18 Accepted:2019-01-01 Published:2019-02-21
  • Contact: Dong ZHENG E-mail:zhengd11@yeah.net
  • Supported by:
    the National Natural Science Foundation of China(51606212);Fundamental Research Funds for the Central Universities, China(2682017CX035)

摘要:

本文以具有绿色无毒、高性能、低成本等诸多优势的N2O-C2烃类燃料单元复合推进剂(即NOFBX)为对象,首先发展了包含52组分、325反应的燃烧化学反应机理模型。该机理不仅能够准确计算N2O热解过程中重要组分的分布,而且能够在较宽的温度、压力、化学计量比范围内准确预测N2O-C2烃类燃料体系的着火延迟时间和层流火焰传播速度。鉴于本文提出的N2O-C2烃类燃料反应机理具有机理规模小、实验验证充分的特点,有望在NOFBX发动机的多维燃烧数值模拟中得到广泛应用。

关键词: 氧化亚氮, 小碳氢燃料, 化学反应机理, 着火延迟时间, 绿色推进剂

Abstract:

In order to meet high-performance propulsion system requirements for aerospace technology and severe future restrictions on hydrazine use, research on non-toxic, high-performance, and low-cost propulsion technology is urgently needed. The N2O-C2 hydrocarbon monopropellant NOFBX (Nitrous Oxide Fuel Blend) provides significant benefits for meeting these criteria and has become a focus of increased research in recent years. In this study, a chemical kinetic model for NOFBX combustion that integrates the reduced C2 sub-mechanism, the N2O sub-mechanism in the literature, and the N2O/CH species reaction mechanism has been developed. The present mechanism consists of 52 species and 325 elementary reactions. For better predictions of ignition and combustion characteristics, the kinetic parameters of the sensitive reactions with comparatively high rate constant uncertainties have been revised. The present model has been validated against published experimental data, including flow reactor results on N2O/H2O/N2 mixture decomposition, shock tube ignition delay times on N2O/C2 hydrocarbons diluted with N2 or Ar mixtures, heat flux of flat flame laminar flame speeds on N2O/C2H2 diluted with N2 mixtures, and Bunsen flame laminar flame speeds on N2O/C2H4 diluted with N2 mixtures. Additionally, this study compares the new model to other published small hydrocarbon fuel kinetic models with a NOx sub-mechanism. The experimental validations show that the present model accurately captures the nitrous oxide decomposition process and precisely predicts N2O, O2, NO, and NO2 vital species concentration distributions. For all N2O-C2 hydrocarbon fuel systems (ethane-, ethylene-, and acetylene-nitrous oxide), the ignition delay times predicted by the present model are in good agreement with the experimental data. Furthermore, at a wider range of initial temperatures (1100-1700 K), initial pressures (0.1-1.6 MPa), and equivalence ratios (0.5-2.0) for the ignition delay times of ethylene-nitrous oxide, the present model exhibits improved predictions of experimental data. For the laminar flame speeds of N2O-C2H2 and N2O-C2H4 mixtures, the present model generally exhibits satisfactory predictions of the experimental data over the whole range of equivalence ratios (0.6-2.0). However, at initial pressure 0.1 MPa and equivalence ratios of 1.0-1.6 for N2O-C2H4 laminar flame speeds, the present model slightly underestimates experimental data. Considering the much higher uncertainty of the measured laminar flame speeds by the Bunsen flame method, this discrepancy is acceptable. Due to the small scale, full experimental validations and good applicability, the present model can be used to further research on multi-dimensional combustion simulation in NOFBX engine combustors.

Key words: Nitrous, Small hydrocarbons, Chemical mechanism, Ignition delay time, Green propellant

MSC2000: 

  • O643