利用定容燃烧弹和高速纹影摄像手段研究了不同初始压力、初始温度、气体稀释度和燃空当量比下乙醇-空气-稀释气预混层流燃烧特性的基础特征参数,如绝热火焰温度、层流燃烧速度、层流燃烧质量流量、层流燃烧火焰厚度和已燃气体Markstein长度。研究结果表明:在给定初始压力、初始温度和气体稀释度的情况下,绝热火焰温度、质量燃烧流量和层流燃烧速度的最大值均出现在当量比1.0~1.1,层流火焰厚度在当量比1.1处取得最小值;已燃气体Markstein长度随当量比的增加呈下降趋势;在给定当量比条件下,绝热火焰温度随初始压力、初始温度的增加而增加,随氮气稀释度的增加而降低;层流燃烧速度随初始压力和氮气稀释度增加而降低,随初始温度增加而增加;层流质量燃烧流量随初始压力和初始温度的增加而增加;随氮气稀释度增加而减小;层流火焰厚度和已燃气体Markstein长度随初始压力和初始温度的增加而减小,随氮气稀释度的增加而增加。
Several fundamental parameters characterizing the ethanol-air premixed mixtures at different equivalence ratios,initial pressures and temperatures,and dilution ratios,like the adiabatic flame temperature,the laminar burning velocity,the laminar burning flux,the laminar flame thickness and the burnt-gas Markstein length,were studied by using a constant volume combustion bomb and high-speed schlieren photography system.The results show that,for ethanol-air premixed mixture at given initial condition,adiabatic flame temperature,laminar burning velocity and laminar burning flux get their maximum values at the equivalence ratios between 1.0 and 1.1,while laminar flame thickness gets its minimum value at the equivalence ratio of 1.1.Markstein length decreases with the increase of equivalence ratio.For ethanol-air premixed mixture at given equivalence ratio,adiabatic flame temperature increases with the increase in initial pressure and temperature,and it decreases with the increase in dilution ratio.Laminar burning velocity decreases with the increase in initial pressure and dilution ratio,and it increases with the increase in initial temperature.Laminar burning flux increases with the increase in initial pressure and temperature,and it decreases with the increase in dilution ratio.Laminar flame thickness and Markstein length decrease with the increase in initial pressure and temperature,and they increase with an increase in dilution ratio.