V形槽结构面源黑体辐射特性评估方法及结构参数优化设计

Radiant Characteristics Evaluation and Structural Parameter Optimization Design of V-Grooved Surface Blackbody

随着红外技术的迅速发展,作为标准辐射源的面源黑体在红外遥感与探测、红外成像等领域得到了日益广泛的应用,但不同形式面源黑体的辐射特性评估方法以及辐射特性与结构参数间的影响关系等问题还没有得到深入的研究.基于这一现状,针对同心圆V形槽结构面源黑体,提出了基于蒙特卡洛全光路跟踪的辐射特性评估方法.首先,通过与精密方法的相互比对验证了方法的正确性及准确程度;然后,基于该方法对V形槽面源黑体的有效发射率进行了评估;最后,对影响辐射特性的主要结构参数及其规律进行了分析研究.实验结果显示,槽夹角越小、涂层本征发射率越高,黑体的有效发射率就越高、越均匀.对于一般性应用可以采用45°或60°槽夹角;为了获取更高的有效发射率,可以采用更小的槽夹角,但涂层本征发射率必须大于等于0.8;采用长径比为2的保护套筒结构可以达到更为理想的辐射特性.

Surface blackbody as standard radiation source is used extensively and increasingly in calibrating various infrared instruments in IR detection and imaging etc. However, so far there has been no in-depth study on the radiant characteristics evaluation methods for various structural surface blackbodies and the relationship between effective emissivity and structural factors In this paper, a radiant characteristics calculation method for V-grooved surface black- body was presented based on Monte Carlo method （MCM）. The exactitude of MCM was first approved by comparison with precise Bedford method. Then this method was applied to V-grooved surface blackbody, and the effects of struc- tural factors on effective emissivity were analyzed. The results demonstrate that effective emissivity and its homogene- ity are improved when small grooved angle and high intrinsic effective coating material are adopted, and higher effec- tive emissivity and better uniformity can be obtained when a guarded sleeve is applied. It is possible to conclude that for general application, the grooved angles of 45~ and 60~ can lead to satisfactory effective emissivity and uniformity; to obtain higher radiant characteristic, smaller grooved angle is required, but the intrinsic emissivity of coating must be greater than or equal to 0.8; to achieve ideal radiant characteristic, it is essential to apply a guarded sleeve with the slenderness ratio of 2.