单元表面间辐射传递系数的新型计算方法

A New Method of Radiative Transfer Coefficient between Unit Surfaces

通过对辐射能量传递过程的分解,建立辐射传递系数与角系数之间的关系,提出了一种计算具有漫反射辐射界面特性的单元表面之间辐射传递系数的新型计算方法。该方法分离了单元表面辐射特性和几何特性对辐射传递系数的影响。分别采用新方法和蒙特卡洛法计算了立方体内部单元表面之间的辐射传递系数,并且从理论上对两种计算方法的耗时性和计算精度进行了分析比较。结果表明,相对于蒙特卡洛法,该方法所需的计算时间更少,而且不随单元表面吸收率的变化而变化;在计算精度上,该方法相对于蒙特卡洛法具有更高计算精度。

By decomposing the transfer process of irradiance energy, the relation between radiative transfer coefficient and angle factor was built, and the new method for computing radiative transfer coefficient between unit surfaces was developed. The new method is only applicable to unit surfaces that owned the character of diffuse emission and diffuse reflection. The effects of the radiation and geometric characters of unit surface were decomposed. The new method and Monte-Carlo method were respectively used to compute the radiative transfer coefficient between unit surfaces inside cube. The computation time and accuracy of the two methods were theoretically analyzed and compared. It shows that the computation time is less than the time Monte-Carlo method needs, and that it is not influenced by surface absorptivity. Compared with Monte-Carlo method, the new method has the higher accuracy.