Radiative entransy flux in enclosures with non-isothermal or non-grey,opaque,diffuse surfaces and its application  

作　　者：CHENG XueTao XU XiangHua LIANG XinGang 

机构地区：[1]Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China

出　　处：《Science China(Technological Sciences)》2011年第9期2446-2456,共11页中国科学（技术科学英文版）

基　　金：supported by Tsinghua University Initiative Scientific Research Program

摘　　要：The spectral radiative entransy flux and the total radiative entransy flux are defined for the steady radiative heat transfer processes in enclosures composed of non-isothermal or non-grey, opaque, diffuse surfaces. Based on the definitions, the radiative entransy flux balance equation and the radiative entransy dissipation functions are introduced under spectral and total wavelength condition. Furthermore, the minimum principle of radiative entransy loss, the extreme principle of radiative entransy dissipation and the minimum principle of radiative thermal resistance are developed. The minimum prirlciple of radiative en- transy loss shows that the potential and the net radiative heat flux distribution which meet the control equations and the boundary conditions would make the radiative entransy loss minimum if the net radiative heat flux or the potential distribution of the radiative heat transfer system is given. The extreme principle of radiative entransy dissipation indicates that the minimum radiative entransy dissipation leads to the minimum average potential difference for the prescribed total radiative heat exchange and the maximum radiative entransy dissipation leads to the maximum radiative heat exchange for the prescribed average potential difference. Moreover, the minimum principle of radiative thermal resistance tells us that the aforementioned extreme values of radiative entransy dissipation both correspond to the minimum value of radiative thermal resistance. Application examples are given for the extreme principle of spectral radiative entransy dissipation and the minimum principle of spectral radiative thermal resistance, and the principles are proved to be applicable.

关 键 词：radiative entransy flux spectral radiative entransy flux non-grey surface radiative entransy principles  radiative heattransfer optimization 

分 类 号：O175.27[理学—数学] TU831.2[理学—基础数学]