NUMERICAL SIMULATION ON MARANGONI MIGRATION OF BUBBLE AND DROP

本文利用Level Set方法,数值模拟了微重力情况下气泡/液滴的Marangoni迁移现象,分析了Marangoni数对迁移速度的影响.数值模拟结果表明,随着Marangoni数的增大,非线性热对流效应的影响会逐渐增大,导致沿相界面温度分布趋于均匀,从而降低迁移运动的驱动力,使气泡/液滴的迁移速度随Marangoni数的增加而逐渐减小

气泡/液滴运动的Level Set方法模拟研究

利用Level Set方法，结合投影法求解了描述气泡/液滴运动的Navier-Stokes方程。对地面常重力场中不同大小的空气泡在高黏度糖浆溶液中的自由上升运动现象，数值模拟结果与实验观测结果符合甚好，表明该方法能够计算大密度比和黏度比$(>1000:1)$情况下的气液两相流动。而对等密度液滴的热毛细迁移现象的数值模拟结果同样能够与实验结果相一致，表明该方法同样适于研究具有Marangoni效应的两相流动现象，特别是在空间微重力环境中的气液两相传热现象中的局部流动与传热问题

单气泡池沸腾过程中的气泡动力学数值模拟研究

本文以单气泡池沸腾作为核态池沸腾现象的模型体系,以避免汽化核心分布的随机性及气泡间相互作用等引起的复杂性,深入研究核态池沸腾过程中的相变及气泡周围细观流动与传热规律。基于Level Set方法建立了描述单气泡池沸腾问题的数值模型,模拟了气泡的生长与脱落过程,并分析了气泡周围细观流动与传热

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies