Propagation of Fronts in Porous Media Combustion

多孔介质燃烧中前沿的传播

• 批准号: 0554775
• 负责人: Peter Gordon
• 金额: --
• 依托单位: New Jersey Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0554775&HistoricalAwards=false
• 关键词: Propagation; Fronts; Porous; Media; Combustion

This research project is focused on mathematical analysis of the propagation and stability of fronts in a porous medium. The project is motivated by recent theoretical advances that revealed a number of new effects and regimes in porous media combustion, such as low-velocity (subsonic) detonation, deflagration to detonation transitions, and various types of instabilities. This work studies a model for combustion in porous media consisting of three degenerate parabolic equations for temperature, concentration of the deficient reactant, and pressure. The project investigates the long-time behavior of the combustion fronts, their stability, and bounds on propagation velocity. Stability will be explored by a combination of numerical and analytical tools. The project also studies the so-called high activation energy limit, as well as the transition from slowly propagating deflagration to detonation. Premixed gas combustion is the combustion of gaseous reactants that are perfectly mixed prior to ignition. The most distinctive feature of premixed combustion is its ability to assume a self-sustained reaction front propagating subsonically or supersonically at a well-defined speed. Combustion fronts constitute a truly fascinating dynamical system, displaying an amazingly rich variety of phenomena, such as non-uniqueness of possible propagation regimes, their birth (ignition) and destruction (extinction), chaotic self-motion and fractal-like growth, and various hysteretic transitions. The current project is concerned with the mathematical analysis of combustion front dynamics in a porous medium, involving evaluation of the propagation velocity, its limits, stability, and the transition from deflagrative to detonative combustion. The results of the work have potential application to engineering design of propulsion systems.

本研究项目的重点是在多孔介质中对锋面的传播和稳定性进行数学分析。该项目的动力来自于最近的理论进展，这些进展揭示了多孔介质燃烧的一些新效应和机制，如低速（亚音速）爆轰、爆燃到爆轰过渡以及各种类型的不稳定性。本文研究了多孔介质中的燃烧模型，该模型由三个退化抛物方程组成，分别代表温度、缺陷反应物浓度和压力。该项目研究了燃烧锋面的长期行为，稳定性和传播速度的界限。稳定性将通过数值和分析工具的结合来探讨。该项目还研究了所谓的高活化能极限，以及从缓慢传播的爆燃到爆轰的转变。预混合气体燃烧是气体反应物在点火前完全混合的燃烧。预混燃烧最显著的特点是它能够形成一个自持续的反应锋面，以一种确定的速度以亚音速或超音速传播。燃烧前沿构成了一个真正迷人的动力系统，展示了令人惊讶的丰富多样的现象，例如可能的传播体制的非唯一性，它们的诞生（点燃）和毁灭（熄灭），混沌自运动和分形生长，以及各种滞后转变。目前的项目涉及多孔介质中燃烧锋面动力学的数学分析，包括传播速度、极限、稳定性以及从爆燃到爆轰燃烧的过渡的评估。研究结果对推进系统的工程设计具有潜在的应用价值。