目标表面地球辐射和地球反照的均匀模拟法

Uniform Simulation of Earth Radiation and Reflective Earth Radiation on Target Surface

对地球面元的方位角和天顶角进行了均匀采样,并将面元位置矢量由球坐标系转化到了地心赤道坐标系中。通过数值积分,计算出了地球反照和地球红外辐射对目标的辐射角系数。计算结果表明,该方法不仅在计算效率和计算精度方面都明显优于随机模拟方法,而且与辐射换热角系数手册数据十分吻合,非常适用于目标热流的计算。

The zenith and azimuth angles of the surface cells of the earth are sampled uniformly. The position of a surface cell is transformed from the sphere reference frame into the earth equatorial reference frame.The geometric factors of earth radiation and earth＇s reflective radiation are calculated through numerical integration.The calculation result shows that this method is better than the random simulation method in calculation precision and efficiency and its data is in most agreement with that in the radiant exchange heat manual.It is very suitable for the calculation of the heat flux of a target.