由长脉冲激光产生的蒸汽泡:在吸附和相位过渡之间进行竞赛
Xuning Zhao1, Wentao Ma1, Junqin Chen2
1Kevin T. Crofton Department of Aerospace and Ocean Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
概括
激光诱导的蒸汽泡形状取决于液体向导和表面蒸发之间的竞争. 随着激光属性的影响,当蒸发超过向导时,长长的气泡会形成.
科学领域:
- 物理 物理学 物理
- 流体动力学 流体动力学
- 激光消光是一种激光消光技术.
背景情况:
- 脉冲激光会产生复杂的,非球形的蒸汽泡.
- 气泡形态可以反映激光束的特征,在梨状和形之间过渡.
研究的目的:
- 调查球形和长长的蒸汽泡形状之间的过渡.
- 了解激光诱导蒸发过程中控制气泡形态的基础物理.
主要方法:
- 开发了一个结合可压缩多相流体动力学,激光辐射和相变的计算模型.
- 模拟了两个实验室实验,使用Holmium:YAG和Thulium纤维激光器.
- 分析了激光辐射,温度,速度和压力的全场结果.
主要成果:
- 泡核和形态的模型预测与实验观测有很好的一致性.
- 确定了泡表面的持续蒸发是动力学的一个关键驱动因素,除了向导外.
- 蒸发持续时间有显著差异:梨状泡<1微秒,延长型泡>50微秒.
结论:
- 假设气泡形态是由于向导和蒸发速度之间的竞争而产生的.
- 模拟结果支持了假设:更快的向导导致球形生长,而更快的蒸发导致延长.
- 更高的激光吸收率和更窄的光束在固定激光功率下促进泡延长.
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