中文摘要：

利用定容燃烧弹试验和数值模拟的方法分析了稀释气种类及掺混量对二甲醚一空气预混合气层流燃烧速度、绝热火焰温度和火焰结构的影响。结果显示：随稀释系数的增大，混合气的层流燃烧速度，绝热火焰温度逐渐减小；在相同的稀释系数条件下，稀释气对二甲醚层流燃烧特性的影响程度按照由氩气（Ar）、氮气（N2）、二氧化碳（CO2）的顺序依次增强；层流燃烧速度随绝热火焰温度的增大而增大，Ar和N2稀释时层流燃烧速度和绝热火焰温度的关系曲线基本重合，CO2稀释时曲线处在较低的位置；Ar和N2在二甲醚燃烧过程中主要通过稀释作用和吸热作用产生影响，而CO2除这两个作用之外，还会参加化学反应，从而进一步影响绝热火焰温度和火焰传播速度。

英文摘要：

Influences of dilution gas kind and dilution ratio on fundamental combustion characteristics of premixed stratified dimethyl ether （DME）/air/dilution mixture, such as stratified combustion speed, adiabatic flame temperature and flame structure, were investigated by using constant volume bomb test and numerical simulation. Results show that with increase of dilution ratio, stratified combustion speed, adiabatic flame temperature of DME flame decease. For a constant dilution ratio, influence degree of dilution gas on DME combustion characteristics increases in the order： Ar-N2-CO2. The stratified combustion speed increases with adiabatic flame temperature increase. For Ar and N2 dilution, the stratified combustion speed and adiabatic flame temperature curves are coincident basically, the curve for CO2 dilution exhibits lower position. Influences of Ar and N2 are mainly due to their dilution and heat-absorbing effects. When CO2 is added, besides the two effects, it may take part in chemical reactions and effect further stratified combustion speed and adiabatic flame temperature.