空泡在水下激光推进不同形状靶材中的作用研究
关键字 空泡 激光推进 几何限制 空泡溃灭
毕业设计说明书（论文）外文摘要
Title Effects of laser-induced cavitation bubble on different geometrical confinements for laser propulsion in water
Abstract
Effects of cavitation bubble for laser propulsion in water are investigated with high-speed photography. Laser propulsions of six kinds of propelled objects made by aluminum are studied in this paper. The kinetic momentum and momentum coupling coefficients gained by the objects after implementation of single laser pulse are investigated experimentally. It is shown that the propulsion effects are better if there is a cavity on the laser irradiated surface of the object, and a hemispherical cavity works better than a 90°-conical cavity. For laser propulsion in water, the sources of the propelling force include the laser ablation shock wave, the bubble oscillating shock waves and the final bubble collapse impact. According to investigations, the major part of propelling power is from the laser ablation shock wave and the final collapse impact. Variation in geometrical confinement of the propelled object influences all three sources of propelling force. Therefore, six kinds of geometrical confinements are designed in this paper.
Keywords Cavitation Laser propulsion Confinement Bubble collapse
目 次
1. 绪论 1
1.1 研究背景 1
1.2 研究意义 2
2. 激光空泡研究进展 4
2.1 空化概念 4
2.2 空泡脉动 5
2.2.1 理想球形气泡 5
2.2.2 非理想空泡 6
2.3 受限空泡 7
2.3.1 射流 7
2.3.2 冲击波理论 9
2.3.3 Splashing 9
2.4 实验方法 10
3. 本文内容 12
3.1 实验装置 12
3.1.1 优尔种推进物体 12
3.1.2 实验装置图 12
3.2 实验准备 14
3.2.1 激光能量与示数关系 14
3.2.2 误差分析 14
3.3 实验结果 14
3.3.1 空泡半径与激光能量关系 14
3.3.2 激光对不同形状物体的推进效果 15
3.3.3 动量耦合系数与激光能量关系 19
3.3.4 空泡脉动对推进效果的影响 21
3.3.5 头部空泡 22
结论 23
参考文献 25
1 绪论
1.1 研究背景
作为高技术领域中重要分支的激光技术的发展推动了一大批行业的面貌发生了变化，例如，激光推进、激光分离同位素、光纤通讯、激光排版、打字与印刷、激光工业加工、光计算、激光计量检测、激光战术模拟、激光核聚变等。可以说，现阶段的激光应用技术已经广泛地应用到工业、农业、医学、军事和科学研究等领域，并给人类带来了巨大的效益。目前世界各国都在大力开发激光技术，这些激光技术应用的重要物理基础涉及激光与物质的相互作用物理学。随着激光技术的广泛应用，这方面的基础研究愈显薄弱，因而广泛地受到了人们的重视[1]。