摘要
为了研究热容激光器冷却过程中激光介质的热力学特性,建立了激光介质热力学理论模型.该模型将介质表面的换热作为瞬态导热微分方程的热源,得到冷却过程中热传导模型.获得了激光介质在冷却过程中的瞬态温度场,进一步得到介质的热应力.利用数值模拟,得到了YAG介质和GGG介质在不同冷却条件下的冷却时间、温差和热应力.表面换热系数从0.1 W?cm-2?K-1增加到0.5 W?cm-2?K-1,冷却时间明显缩短;表面换热系数从0.5 W?cm-2?K-1增加到1 W?cm-2?K-1,冷却时间缩短不明显.对于相同体积、相同初始温度场的YAG介质和GGG介质,YAG介质的冷却时间少于GGG介质的冷却时间.在相同冷却条件下,YAG介质的温差小于GGG介质的温差,YAG介质的最大等效应力小于GGG介质的最大等效应力.
The thermodynamic model of laser medium was established to study the thermodynamic characteristic in laser medium cooling of heat capacity laser. The exchange heat on the end surface of laser medium was regarded as the heat source of the transient heat conduction equation. The heat conduction model in cooling was got. The transient temperature field in the laser medium cooling was got. Then, the thermal stress of the laser medium was got. By using numerical simulation, the cooling time, and the different in temperature and thermal stress of the YAG medium and the GGG medium at different cooling condition were obtained. The cooling time is greatly decreased as the convective heat transfer coefficient is increased from 0.1 W·cm^-2·K^-1 to 0.5 W·cm^-2·K^-1. The cooling time is little decreased as the convective heat transfer coefficient increased from 0.5 W·cm^-2·K^-1 to 1 W·cm^-2·K^-1. The cooling time of YAG medium is less than that of GGG medium at the same volume and the same initial temperture field. The difference in temperatue and the maximal equivalent stress of YAG medium are less than that of GGG medium＇ at the same cooling condition.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2007年第11期1507-1511,共5页
Chinese Journal of Lasers
基金
中国工程物理研究院重大基金资助项目
关键词
激光技术
热容激光器
冷却过程热力学
数值模拟
laser technique
heat capacity laser
thermodynamics in cooling
numerical simulation
