为探索代用燃料液化石油气 L PG和二甲醚 DME的喷雾机理 ,采用 L DA技术测量了喷雾粒子的速度分布。为安全起见 ,用制冷剂 R12作试验液体 ,它与 L PG和 DME有相似的物理特性。为做比较 ,在相同试验条件下对传统柴油喷雾进行了测量。考察了喷雾模式对速度分布的影响。结果表明 ,R12喷雾的速度分布比传统柴油喷雾均匀得多 ,前者的平均径向速度远大于后者。这被认为归因于闪急沸腾大大改善了雾化和液气混合 In order to explore the spray mechanism of LPG and DME as the alternative fuels, the velocity distribution of spray particles was measured by L DA technique. For safety, refrigerant R12 is used as the test fluid, which has similar physical properties to L PG and DME. For comparison, a conventional diesel spray was measured under the same test conditions. The effect of spray pattern on velocity distribution was investigated. The results show that the velocity distribution of R12 spray is much more uniform than the traditional diesel spray, and the average radial velocity of the former is much larger than the latter. This is believed to have greatly improved atomization and liquid-gas mixing due to flash boiling