双平行平面射流与环境流基元反应特性研究  

Elementary reaction characteristics of dual-plane jet flow and ambient flow

作　　者：李岩[1] 曹晴晴 周毅 Li Yan;Cao Qingqing;Zhou Yi(School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学能源与动力工程学院,江苏南京210094

出　　处：《南京理工大学学报》2023年第6期824-835,共12页Journal of Nanjing University of Science and Technology

基　　金：国家自然科学基金(91952105;11802133);中央高校基本科研业务费专项基金(30921011212);江苏省“六大人才高峰”资助项目(2019-SZCY-005)。

摘　　要：为揭示双射流与环境流之间流动-化学反应耦合过程的标量输运机理,采用大涡模拟方法对具有二级非平衡基元反应(A+B→R)的双射流与环境流反应工况进行了研究,达姆科勒数Da为1且雷诺数为2000。首先通过对反应性单射流进行数值模拟,将平均流向速度和平均混合浓度分数等统计量与现有方法结果进行对比,验证了数值方法的准确性;其次,基于化学反应标量输运方程研究了反应性双射流流动-化学反应耦合过程中的标量输运和化学反应特性。结果表明:流场上游湍流/非湍流界面(T/NTI)附近存在1个急剧消耗环境流中反应物B的区域,T/NTI的卷吸过程深刻影响着化学反应;化学反应主要发生在流场上游,T/NTI附近某一时刻产物R的非稳态变化几乎由化学反应产生和对流输运过程决定,而流场下游湍流区域某一时刻产物R的非稳态变化主要取决于对流作用;统计平均下,在6<x/d<20范围内,流场流向对流作用和法向对流作用对产物R的输运收支平衡。In order to reveal the scalar transport mechanism of the flow-chemical reaction coupling process between the dual-plane jet and the environmental flow,the large eddy simulation method is used to study the reaction condition of the dual-plane jet and the environmental flow with the second-order non-equilibrium elementary reaction(A+B→R).In the study,the Damk hler number(Da)is 1 and the Reynolds number is 2000.Firstly,through the numerical simulation of a single reactive jet,the statistics such as the mean streamwise velocity and the mean mixture concentration fraction are compared with the previous results to verify the accuracy of present numerical method.Secondly,based on the chemical reaction scalar transport equation,the scalar transport and chemical reaction characteristics of reactive dual-plane jet in flow-chemical reaction coupling process are studied.The results show that near the turbulent/non-turbulent interface(T/NTI)upstream of the flow field,there is a region where reactant B is consumed sharply,and the entrainment process of T/NTI profoundly affects the chemical reaction;the chemical reaction mainly occurs in the upstream of the flow field,the unsteady change of product R at a certain time near T/NTI is almost determined by the chemical reaction and advection transport process,while the unsteady change of product R at a certain time in the turbulent region downstream of the flow field mainly depends on the advection;when the mean statistics are carried out,the transport of streamwise advection and the transport of normal advection on product R budget in the range of 6<x/d<20.

关 键 词：双平行平面射流 环境流 基元反应 大涡模拟方法 标量输运方程 湍流 计算流体力学 对流输运过程 

分 类 号：O358[理学—流体力学]