二甲基醚喷雾碰壁实验研究

利用压力定容室配以高速摄影机对柴油代用燃料二甲基醚（DME）进行了喷雾碰壁实验研究，考察了碰壁角度、碰壁距离等因素对二甲基醚喷雾碰壁过程的影响．同时，对柴油的喷雾碰壁也进行了相关的对比实验．基于对实验结果的分析，获得了二甲基醚喷雾碰壁特性的一般规律：随着碰壁入射角的增大，近壁区的空气卷吸作用加强，着壁液滴的数量减少，油膜厚度变薄，喷雾体的壁面扩展度增加；随着碰壁距离增加，喷雾体的壁面扩展度和厚度都有所降低，近壁区的空气卷吸作用减弱；与柴油相比，DME喷雾体的壁面扩展度和厚度较小，说明DME比柴油蒸发速度快，雾化质量较好．

Experimental research on the spray wall-impingement of dimethyl ether

The spray wall-impingement experiments of dimethyl ether(DME) were carried out in constant volume chamber by using high speed camera, and the influence of impinging angle,impinging distance,etc.on the wall-impingement characteristics of DME were discussed.And at the same time,the relevant experiments of diesel were performed.According to the experimental results,the general characteristics of the wall-impingement of DME was obtained: With the increase of the impinging angle,the air entrainment near the wall was strengthened,the wall spread distance of the droplets on the wall increased,but the thickness of liquid film and the number of droplets sticking on the wall decreased.With the increase of impinging distance,both the wall spread distance and the thickness of liquid film on the wall was decreased,and the air entrainment near the wall was weakened.The wall spread distance and thickness of DME liquid film are smaller in comparison with those of diesel,which showed the evaporation rate is faster and the atomization quality of DME is better than those of diesel.