Reaction Zones and Their Structure in MILD Combustion
Reaction Zones and Their Structure in MILD Combustion
复制标题
轻度燃烧中的反应区及其结构
DOI：
10.1080/00102202.2014.902814
复制
发表时间：
2014
影响因子：
1.9
通讯作者：
T. Leung
中科院分区：
文献类型：
--
作者：
Y. Minamoto;N. Swaminathan;R. Cant;T. Leung
采用三维直接数值模拟（DNS）方法，对中等和强烈低氧稀释（MILD）条件下长方体内的湍流燃烧进行了数值模拟。初始和流入的混合物和湍流场被仔细地构造，以代表涉及未燃烧和燃烧气体的部分混合袋的MILD条件。燃烧动力学模型使用的甲烷-空气燃烧的骨架机制，包括非统一的刘易斯数的物种和温度依赖的传输特性。分析DNS数据以研究MILD反应区结构及其行为。结果表明，瞬时反应区呈回旋状，回旋度随稀释度和湍流度的增加而增大。由于混合物的不均匀性和高湍流水平，反应区的相互作用频繁发生，并且在计算域的大部分中展开。这些相互作用导致局部增厚的反应区产生的外观分布燃烧，尽管存在局部薄的反应区。一个典型的MILD火焰元素，被称为MIFE，提出，它代表了主要物种的平均质量分数的变化相当不错，虽然一个完全有代表性的典型元素需要包括反应区的相互作用和相关的增厚效应的平均反应速率的影响。
Three-dimensional direct numerical simulation (DNS) of turbulent combustion under moderate and intense low-oxygen dilution (MILD) conditions has been carried out inside a cuboid with inflow and outflow boundaries on the upstream and downstream faces, respectively. The initial and inflowing mixture and turbulence fields are constructed carefully to be representative of MILD conditions involving partially mixed pockets of unburned and burned gases. The combustion kinetics are modeled using a skeletal mechanism for methane-air combustion, including non-unity Lewis numbers for species and temperature-dependent transport properties. The DNS data is analyzed to study the MILD reaction zone structure and its behavior. The results show that the instantaneous reaction zones are convoluted and the degree of convolution increases with dilution and turbulence levels. Interactions of reaction zones occur frequently and are spread out in a large portion of the computational domain due to the mixture non-uniformity and high turbulence level. These interactions lead to local thickening of reaction zones yielding an appearance of distributed combustion despite the presence of local thin reaction zones. A canonical MILD flame element, called MIFE, is proposed, which represents the averaged mass fraction variation for major species reasonably well, although a fully representative canonical element needs to include the effect of reaction zone interactions and associated thickening effects on the mean reaction rate.
勘误表：使用直接数值模拟测量静态预混 V 型火焰的几何特性和湍流火焰速度
DOI：
10.1007/s10494-010-9304-1
发表时间：
2010
期刊：
Flow, Turbulence and Combustion
影响因子：
--
作者：
Dunstan T
通讯作者：
Dunstan T
DOI：
10.1007/s10494-010-9284-1
发表时间：
2011-12
期刊：
Flow, Turbulence and Combustion
影响因子：
--
作者：
T. Dunstan;N. Swaminathan;K. Bray;R. Cant
通讯作者：
T. Dunstan;N. Swaminathan;K. Bray;R. Cant
火焰几何形状对湍流预混火焰传播的影响：DNS 研究
影响因子：
3.7
作者：
Dunstan T
通讯作者：
Dunstan T