浮升力对T型管道内冷热流体混合过程热波动的影响  

Influence of buoyancy on thermal fluctuation of fluid mixing in T-junction

作　　者：卢涛[1] 朱兴国[1] 

机构地区：[1]北京化工大学机电工程学院,北京100029

出　　处：《热科学与技术》2011年第4期305-311,共7页Journal of Thermal Science and Technology

基　　金：国家自然基金资助项目(50906002)

摘　　要：利用Fluent软件对T型管道内冷热流体混合过程进行了大涡模拟,考虑了温差引起的浮升力,获得了混合过程的瞬时温度和瞬时速度,通过定义时均值和均方根值来描述温度和速度的平均大小和波动程度。数值模拟结果表明,理查德森数对冷热流体的混合有着重要的影响:当理查德森数为负值且绝对值越大,则温度和速度的波动也就越大;相反,当理查德森数为正值且值越大,则温度和速度的波动反而越小。研究为减小T型结构管内流体混合的热波动而对管内的冷热流体的合理布置提供了理论依据。Large eddy simulation was used for cold and hot fluids mixing ot the l-junction with consideration of buoyancy based on FLUENT platform, which acquires the instantaneous temperature and velocity of fluid mixing. The value of defining normalized mean value and root-mean square were used to respectively describing the time-averaged temperature and temperature fluctuation intensity. The numerical results show that, Richardson number has a significant impact on the fluctuation intensity of hot and cold mixing. The fluctuation intensities of temperature and velocity will be greater if Richardson number is negative and its absolute value is larger; on the contrary, the fluctuation intensities will be smaller when the Richardson number is positive and larger. The research may provide a base guideline on theory for the reasonable arrangement of the cold and hot water in the T- junction to reduce the thermal fluctuation.

关 键 词：T型管道 浮升力 大涡模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]