基于化学反应动力学耦合G方程的定容弹爆震燃烧研究

发布时间：2019-03-31 09:22

【摘要】：由于爆震受多方面的因素共同影响,且这些因素往往是相互耦合在一起,直接在内燃机上对各因素进行解耦进而研究单因素对爆震的影响几乎不可能。针对上述问题,首先基于化学反应动力学和G方程火焰面模型建立了长方体燃烧弹内的爆震燃烧三维CFD模型;然后在该模型基础上把初始压力、初始气温和初始壁温(末端)设为独立变量,系统地研究了各变量对正庚烷与空气混合气的爆震界限及爆震强度的影响。结果表明:当初始压力不高于0.25 MPa时,初始气温和末端壁温在300~700K之间无论如何变化都不会发生爆震;当初始气温不高于450K时,初始压力在0.2~0.5 MPa之间、末端壁温在300~700K之间无论如何变化也都不会发生爆震。同时发现最大压力振幅可作为发生爆震与否的判据,本研究中只要最大压力振幅不高于0.02 MPa即不会发生爆震。
[Abstract]:Because detonation is affected by many factors, and these factors are often coupled together, it is almost impossible to decouple each factor directly on the internal combustion engine and then study the influence of single factor on detonation. In order to solve the above problems, firstly, based on chemical reaction kinetics and G equation flame surface model, a three-dimensional CFD model of detonation combustion in a rectangular combustion bomb is established. Based on the model, the initial pressure, initial air temperature and initial wall temperature (end) are set as independent variables, and the effects of each variable on the knock limit and detonation strength of n-heptane-air mixture are systematically studied. The results show that when the initial pressure is less than 0.25 MPa, the initial temperature and the end wall temperature change between 300 K and 700 K, and the detonation will not occur in any case. When the initial temperature is less than 450K, the initial pressure is between 0.2 and 0.5 MPa, and the temperature of the end wall is between 300 and 700K. The detonation will not occur in any case when the initial temperature is not higher than 450K. At the same time, it is found that the maximum pressure amplitude can be used as a criterion for the occurrence of detonation or not. In this study, as long as the maximum pressure amplitude is less than 0.02 MPa, the detonation will not occur.
【作者单位】：上海交通大学机械与动力工程学院;河南科技大学交通与车辆工程学院;
【基金】：内燃机燃烧学国家重点实验室开放基金资助项目(K2014-2) 上海市教育委员会科研创新项目(14ZZ022)
【分类号】：TK401

【相似文献】