摘要
后台阶流动是计算流体力学领域十分重要的课题,但是后台阶流动与化学反应耦合的数值研究则比较少见。文中使用雷诺应力模型模拟后台阶流动的速度场,使用标量联合概率密度函数(PDF)方程模拟化学反应项,并将化学反应项的结果作为源项引入雷诺应力模型,模拟了后台阶流动中的甲烷与氧气的缓慢氧化反应。结果发现:雷诺应力模型能够很好地模拟冷场条件下的后台阶流动,数值计算的结果与文献中实验的结果相当吻合。当有氧化反应的时候流场速率的分布对氧化反应的结果有明显的影响;在速率比较小,化学反应物停留时间长的流场区域,反应比较完全;同时,速度场的分布还将影响生成物的浓度分布。但是在文中的条件下反应对流场的影响很小,而不同的反应机制对反应结果有明显影响。
The flow over backward-facing step is an important problem in computational fluid dynamic,but the numerical studies of such flow coupled with chemistry reaction are few.Reynolds stress model（RSM） was used in the simulation of the velocity field of flow over a backward-facing step and the chemistry reaction was simulated by using the composition probability density function（PDF） method.The slow oxidation reaction of oxygen and methane over the backward-facing step was simulated,in which the chemistry reaction is used as the source term of the RSM equations.The results show that backward-facing step flow can be simulated well in cool condition by using the Reynold stress model and the numerical results also agree with the experiment well according to the literature.The oxidation reaction is influenced by the distribution of flow velocity evidently.The reaction would proceed completely in the flow region where the velocity is slow and the reactant stays longer time.The distribution of the velocity also affects the distribution of products concentration,but the chemistry reaction affects the flow little under the aforesaid conditions.The effects of different reaction mechanism on reaction results are different obviously.
出处
《化学工程》
CAS
CSCD
北大核心
2011年第10期87-91,共5页
Chemical Engineering(China)
关键词
联合PDF模型
雷诺应力模型
后台阶反应流
反应机制
composition PDF model
Reynolds stress model
backward-facing step reaction flow
reaction mechanism
