Studies on Micro Structure and Dynamic Behavior of Stretch-Controlled Flames

拉伸控制火焰的微观结构和动态行为研究

基本信息

批准号：
17560195
负责人：
TAKAGI Toshimi
金额：
$ 2.35万
依托单位：
Osaka Sangyo University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17560195/
关键词：
Diffusion flames Premixed flames Spherical flames Stretch rate Burning velocity Extinction Hydrogen and methane Numerical computation 平面予混合火炎燃焼率平面拡散火炎消炎局所性対流の影響

项目摘要

Numerical computations of laminar flames have been conducted taking into account detailed chemical kinetics and multi-component diffusion. Diffusion flames, flat premixed flames and spherical flames considered of different stretch rate.In the diffusion flames, (1) There are two types of extinction, the intermittent and the perfect extinction. (2) Extinction occurs slightly in down stream where local stretch rate is the largest. (3) The local stretch rate is much affect the extinction. (4) The convection flow along the flamelet changes the extinction limit.In the flat premixed flame, (1) Symmetrical twin flame is formed As the counter velocity increases, the peak of the heat release rate comes to the central part. (2) The burning velocity increases with increasing the stretch rate, but the burning rate decreases with increasing the stretch rate.The effects of the stretch rate are investigated on the burning velocity in three kind of hydrogen/air flames, that is, outwardly propagating (OPF), inwardly propagating (IPF) and stationary (SF) spherical Direction of the flame propagation and radius of the flame change the stretch rate.(1) The burning velocity is changed for the smaller radius than 5mm. For the IPF, the flame velocity becomes large for the equivalence ratio ¢ larger than 0.7. But, for the smaller Φ, the results is opposite. The change is opposite for the OPF and IPF. (2) The stretch rate of the SF is zero, but the burning velocity has a wide range. (3) The burning velocity is dominated by not only the stretch rate but also the Lewis number, because the burning velocity has the opposite results assuming different diffusivities.

考虑到详细的化学动力学和多组分差异，已经进行了层状火焰的数值计算。散布火焰，平坦的预混合火焰和视线不同的伸展速率。在扩散火焰中，（1）有两种类型的延伸，间歇性和完美的扩展。（2）灭绝发生在局部拉伸速率最大的下流流中。（3）局部拉伸速率极大地影响了扩展。（4）沿着火焰的转化流改变了延伸极限。在平坦的预防火焰中，（1）随着计数器速度的增加，对称双火焰形成，热释放速率的峰值出现到中心部分。 (2) The burning velocity increases with increasing the stretch rate, but the burning rate decreases with increasing the stretch rate.The effects of the stretch rate are investigated on the burning velocity in three kind of hydrogen/air flames, that is, Outwardly propagating (OPF), inwardly propagating (IPF) and stationary (SF) spherical Direction of the flame propagation and radius of the flame change the stretch速率。（1）燃烧速度的速度比5mm较小的半径更改。对于IPF，对于大于0.7的等效比率¢，火焰速度变得很大。但是，对于较小的φ，结果相反。更改与OPF和IPF相反。（2）SF的拉伸速率为零，但是燃烧速度的范围很大。（3）燃烧速度不仅由延长速度，而且由刘易斯数量主导，因为燃烧的速度假设有不同的差异，其结果相反。