Photothermal probe beam deflection measurement of thermal diffusivity of atmospheric air

Yun, Sangwoon; Oh, K. H.; Ryu, Kwon-Sang; Kim, Chang-Geon; Park, H. L.; Seo, Hyunwoong; Kum, Chae

doi:10.1007/bf00694781

Cited by 7 publications

(1 citation statement)

References 28 publications

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“…Additionally, the parameter of thermal diffusivity has a greater effect on the simulated results than other thermodynamical parameters. Although no data are available for higher temperatures, it has been indicated that the thermal diffusivity of air varies from 0.23 to 0.4 (cm 2 •s −1 ) (0.23 was used in our model) when heated from 300 K to 365 K [33]. However, in our experiments air is mixed with lots of water droplets or ice crystals, the thermal diffusivity will decrease dramatically because the thermal diffusivity of ice and water is ~10% and ~1% of that of air, respectively [34], leading to the result that the present model probably overestimates the heat accumulation/temperature and the thermal diffusive area, especially for higher chopping rates.…”

Section: Results and Analysismentioning

confidence: 99%

Laser filamentation induced air-flow motion in a diffusion cloud chamber

Sun¹,

Liu²,

Wang³

et al. 2013

Opt. Express

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We numerically simulated the air-flow motion in a diffusion cloud chamber induced by femtosecond laser filaments for different chopping rates. A two dimensional model was employed, where the laser filaments were treated as a heat flux source. The simulated patterns of flow fields and maximum velocity of updraft compare well with the experimental results for the chopping rates of 1, 5, 15 and 150 Hz. A quantitative inconsistency appears between simulated and experimental maximum velocity of updraft for 1 kHz repetition rate although a similar pattern of flow field is obtained, and the possible reasons were analyzed. Based on the present simulated results, the experimental observation of more water condensation/snow at higher chopping rate can be explained. These results indicate that the specific way of laser filament heating plays a significant role in the laser-induced motion of air flow, and at the same time, our previous conclusion of air flow having an important effect on water condensation/snow is confirmed.

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Section: Results and Analysismentioning

confidence: 99%