甲醇-空气-氮气混合气预混球型火焰的试验研究  

Experimental Study on Premixed Combustion of Spherically Propagating Methanol-Air-Nitrogen Flame

作　　者：王显刚[1] 黄佐华[1] 张志远[1] 向俊[1] 王锡斌[1] 苗海燕[1] 蒋德明[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《内燃机学报》2009年第3期207-214,共8页Transactions of Csice

基　　金：国家自然科学基金重点项目(50576070);国家自然科学基金创新群体项目(50521604)

摘　　要：利用高速纹影摄像法在定容燃烧弹内研究了不同燃空当量比、初始压力、初始温度和气体稀释度下甲醇-空气-氮气混合气预混球型火焰的发展特性以及3种火焰锋面的不稳定性。获得了不同初始状态下的层流燃烧速度、质量燃烧流量和马克斯坦长度。高的初始压力时,火焰锋面生成的裂纹发展并形成细胞状结构。稀混合气时,浮力和电极的冷却作用对火焰的发展有重要影响。当量比在化学计量比附近时,随着初始温度的提高,流体动力学不稳定性被抑制。随着初始压力的增加,流体动力学不稳定性增强。稀释气的加入抑制了火焰锋面流体动力学的不稳定性。Propagation and development characteristics of surface instability of the spherical premixed flames for methanol-air-nitrogen mixtures were studied by using a constant volume combustion chamber and high-speed schlieren photography system. The laminar burning velocities, the mass burning fluxes, and the Markstein lengths were obtained at different equivalence ratios, pressures, initial temperatures and initial dilution ratios. At the elevated pressures, the cracks on the flame surface branch and develop into the cell structure. For very lean mixture combustion, the buoyancy effect and cooling effect from the spark electrodes have a significant impact on the flame propagation. The hydrodynamic instability is inhibited with the increase of initial temperature around the stoiehiometric equivalence ratio while it is enhanced with the increase of initial pressure. Mixture dilution can suppress the hydrodynamic instability.

关 键 词：甲醇 球型火焰 预混燃烧 火焰不稳定性 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]