Temperature fluctuations and heat transport in partitioned supergravitational thermal turbulence  

隔板超重力热湍流中的温度脉动和热输运

作　　者：Dongpu Wang Jing Liu Rushi Lai Chao Sun 王东璞;刘婧;赖茹诗;孙超

机构地区：[1]Beijing Key Laboratory of Space Thermal Control Technology,Beijing Institute of Spacecraft System Engineering,Beijing,100094,China [2]Center for Combustion Energy,Key Laboratory for Thermal Science and Power Engineering of MoE,and Department of Energy and Power Engineering,Tsinghua University,Beijing,100084,China [3]Department of Engineering Mechanics,School ofAerospace Engineering,Tsinghua University,Beijing,100084,China

出　　处：《Acta Mechanica Sinica》2024年第6期20-30,共11页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11988102);the New Cornerstone Science Foundation through the XPLORER PRIZE.

摘　　要：We report an experimental study of the local temperature fluctuationsδT and heat transport in a partitioned supergravitational turbulent convection system.Due to the dynamics of zonal flow in the normal system without partition walls,the probability density function(PDF)at a position in the mixing zone exhibits a downward bending shape,suggesting that the multi-plume clustering effect plays an important role.In partitioned system,zonal flow is suppressed and the PDFs indicate that the single-plume effect is dominant.Moreover,statistical analysis shows that the PDF ofδT is sensitive to supergravity.Additionally,the thermal spectra follow P(f)∼f^(-5) in the normal system,which is relevant to the zonal flow.The absolute value of the scaling exponent of P(f)and the scaling range become small in the partitioned system,which provides another evidence for the influence of zonal flow on the energy cascade.Further,heat transfer enhancement is found in the partitioned system,which may result from zonal flow being restricted and then facilitating the radial movement of thermal plumes to the opposite conducting cylinder.This work may provide insights into the flow and heat transport control of some engineering and geophysical flows.本文报道了隔板超重力湍流对流系统中的局部温度波动δT和热输运的实验研究.在没有隔板的正常系统中,由于纬向流流动的动力学,混合区中某位置的概率密度函数(PDF)呈现向下弯曲的形状,表明多羽流聚集效应起着重要作用.在隔板系统中,纬向流受到抑制,PDF表明单羽流效应占主导地位.此外,统计分析表明,δT的PDF对超重力是敏感的.此外,在正常系统中,热能谱遵循P(f)∼f^(-5),这与纬向流有关.在隔板系统中,P(f)的标度指数的绝对值和标度范围变小,这为纬向流对能量级串的影响提供了另一个证据.此外,在隔板系统中发现了传热增强,这可能是由于纬向流受限,进而促进了羽流向对侧导热圆柱的径向运动.这项工作为理解一些工程和地球物理流提供了思路.

关 键 词：Partitioned turbulent convection SUPERGRAVITY Probability density function Power spectra Heat transfer 

分 类 号：O357.5[理学—流体力学]