Apparent Directionaｌ Emittances of v-Groove， Circular Arc Groove and Random Rough Surfaces of Metals(Part 2) 　?Comparison between 1st Approximate and 2nd Approximate ?

摘要

The exact formula，which is developed by Fresnel from the electromagnetic theory to explain the emissive characteristics of some metallic flat surfaces，is a complicated expression and it is a difficult problem to analyze the apparent directional emittance of metallic random rough surfaces by applying directly the exact formula to these surfaces. In his report，therefore，two approximate formulas of the directional emissivity introduced by Schmidt and others from Fresnelu27s formula，one simple formula used already in the published papers and the other a more complicated formula，are adopted to　analyze　the　apparent　directional　emittances　of　the　v-groove rough　surface，the circular　arc　groove　rough　surface　and　the random　rough surface　of　metals. The calculated values from both formulas are comPared with each other and are shown in the graphic expressions.