Regarding emissivity

kishan kumar jaiswal · November 15, 2013, 03:21

What is the differences between the external emissivity and the internal emissivity? please explain it clearly.

Rami · November 18, 2013, 04:00

This sounds like FLUENT terminology. If so - I recommend asking in the FLUENT forum. In what follows I'll ignore their interpretation (which is not fully clear to me) and give you mine.

Suppose you have a semitransparent domain with some of its boundary surfaces facing the ambient surroundings. This surface has two sides, which may have different emissivities. I would call the emissivity of the side towards the inner domain "internal emissivity", and the other, facing the surroundings, "external emissivity".

November 15, 2013, 03:21	Regarding emissivity	#1
kishan kumar jaiswal New Member Kishan Kumar Jaiswal Join Date: Nov 2013 Posts: 4 Rep Power: 12	What is the differences between the external emissivity and the internal emissivity? please explain it clearly.

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November 18, 2013, 04:00		#2
Rami Senior Member Rami Ben-Zvi Join Date: Mar 2009 Posts: 155 Rep Power: 17	This sounds like FLUENT terminology. If so - I recommend asking in the FLUENT forum. In what follows I'll ignore their interpretation (which is not fully clear to me) and give you mine. Suppose you have a semitransparent domain with some of its boundary surfaces facing the ambient surroundings. This surface has two sides, which may have different emissivities. I would call the emissivity of the side towards the inner domain "internal emissivity", and the other, facing the surroundings, "external emissivity".