均匀分布纳米粒子系近场辐射热扩散特性  

Near-field Radiative Heat Diffusion Characteristics of Uniformly Distributed Particulate System

作　　者：罗明罡 高永旺 赵军明[1] 刘林华 LUo Minggang;GAo Yongwang;ZHAO Junming;LIU Linhua(Harbin Institute of Technology,School of Energy Science and Engineering,Heilongjiang,Harbin 150001,China;Shandong University,School of Energy and Power Engineering,Qingdao 266237,China)

机构地区：[1]哈尔滨工业大学能源科学与工程学院,哈尔滨150001 [2]山东大学(青岛)能源与动力工程学院,青岛266237

出　　处：《工程热物理学报》2023年第7期1959-1965,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.51976045)。

摘　　要：当粒子系中粒子平均间距接近甚至小于热辐射特征波长时,由于倏逝波贡献,其辐射换热热流可远超黑体辐射极限热流。由于存在复杂近场作用,密集粒子系内近场辐射热扩散特性尚不清晰。本文基于涨落电磁理论研究了均匀分布纳米粒子系的近场辐射热扩散特性。研究发现:通过与离散尺度多体辐射换热理论及动理学理论关于金属及电介质粒子链近场辐射换热结果对比,常规热扩散理论可更准确地用于研究粒子系近场辐射热扩散特性,SiC纳米粒子链辐射等效导热系数随温度增大而增大,且温度只影响辐射等效导热系数的大小,而对其光谱峰值频率则无影响。当粒子间距一定时,粒子系辐射等效导热系数随粒子尺寸的增大而增大,更多能量可以在大颗粒构成的粒子链上传递。紧密堆积的粒子系内近场光子隧穿作用较强,其辐射等效导热系数也大于较稀疏粒子系的辐射等效导热系数。When the average spacing of particles in a dense particle system is close to or even smaller than the characteristic wavelength of thermal radiation,the radiative heat flux can far exceed the limit set by the black body radiation law due to the contribution of evanescent waves.The characteristics of near-field radiative heat diffusion in dense particulate system are still unclear because the complex near-field effects.In this paper,the near-field radiative heat diffusion properties of uniformly distributed nanoparticle systems are studied using the theory of fluctuational electrodynamics.By comparing the results of near-field radiative heat transfer of metal and dielectric particle chains with that by using the particle-scale many-body radiative heat transfer theory and kinetic theory,the normal heat diffusion theory is more accurate to study the near-field radiative heat diffusion characteristics of particulate systems.The radiative effective thermal conductivity of SiC nanoparticle chains increases with temperature,and the temperature only affects the magnitude of the radiative effective thermal conductivity,but has no effect on its spectral peak frequency.When the particle spacing is fixed,the radiative effective thermal conductivity of the particle system increases with the particle size,and more energy can be transferred on the particle chain composed of the large particles.Because near-field photon tunneling effect is stronger in closely packed particle system,the radiative effective thermal conductivity is much larger than that of the sparse particulate system.

关 键 词：辐射换热 近场热辐射 纳米粒子系 热扩散特性 辐射等效导热系数 

分 类 号：TK121[动力工程及工程热物理—工程热物理]