论文部分内容阅读
介绍了一种动态自适应化学机制(dynamic adaptive chemistry,DAC)方法。采用直接关系图深度搜索算法,在燃烧过程的不同时刻点,根据当地的热化学状态对详细化学反应机制进行简化,得到即时的当地简化机制,并将该简化机制应用于下一时间步的计算。求解描述化学反应动力学的控制方程时,只对活跃组分进行求解,非活跃组分保持质量份额不变,且可作为基元反应的第三体。基于DAC方法,对包含558种组分、2539个基元反应的正庚烷详细机制定压绝热大空间自燃着火过程进行模拟,得到了精确的温度、主要组分质量份额变化曲线以及着火延迟时间等参数。与详细机制模拟结果进行了对比,模拟用时不足基于详细机制的1/15,证明了该方法的正确性与高效性。
A dynamic adaptive chemistry (DAC) method is introduced. Using the direct relation graph depth search algorithm, the detailed chemical reaction mechanism is simplified according to the local thermochemical state at different time points of the combustion process to obtain an immediate local simplification mechanism, and the simplified mechanism is applied to the calculation of the next time step . When solving the governing equations describing the chemical reaction kinetics, only the active components are solved, while the inactive components remain the same mass fraction and can be used as the third body of the elementary reaction. Based on the DAC method, a detailed pyrolysis mechanism of n-heptane containing 558 components and 2539 elementary reactions was carried out to simulate the large-scale spontaneous combustion process. The accurate temperature, the change of mass fraction of the main components and the ignition delay time Other parameters. Compared with the simulation result of the detailed mechanism, the simulation time is less than 1/15 based on the detailed mechanism, which proves the correctness and efficiency of the method.