双模态冲压发动机模态转换过程中的迟滞问题研究

项目名称： 双模态冲压发动机模态转换过程中的迟滞问题研究

项目编号： No.51276007

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 能源与动力工程

项目作者： 徐旭

作者单位： 北京航空航天大学

项目金额： 80万元

中文摘要： 对双模态冲压发动机燃烧模态转换过程中的迟滞问题开展实验和数值模拟研究。实验基于长时间直连式超燃实验台，分别采用煤油和乙烯为燃料，凹腔、支板和气动斜坡为火焰稳定器，在连续工作条件下完成燃料喷射位置、当量比的改变，实现亚燃和超燃模态的相互转换。通过分析壁面压力数据判别燃烧模态；通过TDLAS技术测量局部火焰温度和燃烧产物浓度分析燃烧状态的强弱；通过高速纹影捕捉模态转换过程中的动态图象；通过高频压力测量捕捉模态转换过程中压力振荡的特征频率。采用非定常流场计算方法模拟模态转换过程，多级Runge-Kutta法用于时间离散，AUSM系列格式用于空间离散，火焰面模型或有限速率化学动力学模型结合离散相两相流模型、PDF湍流燃烧模型模拟碳氢燃料的燃烧。通过本项目的研究，力争从实验现象上揭示迟滞发生的影响因素，从数值计算结果中发掘产生迟滞的流场细观特征，探讨迟滞现象的产生机理和工程上控制迟滞发生的有效方法。

中文关键词： 超燃冲压发动机；超声速燃烧；模态转换；迟滞；火焰面

英文摘要： An experimental and computational study on the hysteretic phenomena in the mode transition process of the dual-mode scramjet will be performed. The experiments are conducted at a long operating time direct connect scramjet facility. Kerosene and ethylene are selected as fuel, and the cavity, strut and aero-ramp act as flameholders in the experiments. During the long time experiment, the mode transition will be realized from ramjet to scramjet and vice versa by means of adjusting the fuel injection position and euqivalence ratio. Static wall pressure data are used to analyze the combustion efficiency and combustion mode. Tunable diode laser absorption spectrum(TDLAS) will be used to measure the combustion temperature and species, high speed schlieren will be preformed to capture the mode transition images, and high frequency dynamic pressure measurement will be used to capture the characteristic frequency during the mode transision. Unsteady algorithms will be used in the mode tansition numerical simulation, multi stage Runge-Kutta method for the time integration and AUSM series algorithms for the space discretization. Both gas phase and gas-liquid two phase combustion will be modeled, steady flamelet model or finite rate chemical reaction model for the reaction of hydrocarbon, propability density function(PDF) m

英文关键词： scramjet；supersonic combustion；mode transition；hysteresis；flamelet