热分层弯管热波动及其削弱机理研究

Investigations of thermal fluctuation and its weaken mechanism in an elbow pipe with thermal stratification

中文关键词: 弯管,热波动,削弱,大涡模拟

英文关键词: elbow  pipe, thermal  fluctuation, weaken, large  eddy simulation

中文摘要:

      热分层弯管中的热波动容易诱发热疲劳,越来越受到核电工程与技术的关注。本文对弯管内热分层的流动与传热机理进行研究,建立数学模型,运用FLUENT软件,对有/无防涡器条件下T型弯管内流体的温度波动过程进行了大涡模拟,获得了弯管处无量纲温度波动曲线和无量纲均方根温度。数值模拟结果表明,加入防涡器后,由于管内湍流减弱,防涡器下方弯管处温度波动减弱,热波动受到抑制。

英文摘要:

      Thermal fluctuation in bent pipe with thermal stratification is easy to induce thermal fatigue, so it is more and more get the attention of nuclear engineering and technology. This work focuses on a research of the flow and heat transfer mechanism of thermal stratification in bent pipe, establishes the mathematical model, the temperature fluctuation of fluids is simulated by large eddy simulation on FLUENT platform, with considers whether it contains vortex breaker, which acquires the dimensionless temperature fluctuation graph and RMS dimensionless temperature of an elbow pipe. The numerical results show that, due to the weaken of turbulent in pipe, temperature fluctuation of elbow-pipe below the vortex breaker is declined with consideration of vortex breaker, thermal fluctuation is suppressed.