Absorption Coefficients

September 12, 2003, 11:04

Hi all,

Can anyone tell me how or where i can obtain values for the Absorption Coefficient of metals.

I think i need these values for DO radiation modelling in a furnace using FLUENT, I'm not sure can someone please advise?

Cheers

Mark

September 15, 2003, 04:01

Hi Mark,

The absorption coefficient (in 1/length units) refers to the relative absorption of radiation along the ray path within a participating medium. This is in contrast to absorptivity of a surface (dimensionless).

Do you treat the metal as a semitransparnt medium using the Discrete Ordinates?

Rami

September 19, 2003, 06:15

The absorption coefficient of a solid should be set to 0 in Fluent.

September 22, 2003, 08:11

Hi Erwin,

Thanks for the advice. Fluent has a default of 0.01 for absorption coeff. for solids. Any comments???

Mark.

September 22, 2003, 09:22

It is possible to have non-zero absorption for solids if they are participating (i.e., semi-transparent). Glass is a straighforward example.

September 12, 2003, 11:04	Absorption Coefficients	#1
Mark Guest Posts: n/a	Hi all, Can anyone tell me how or where i can obtain values for the Absorption Coefficient of metals. I think i need these values for DO radiation modelling in a furnace using FLUENT, I'm not sure can someone please advise? Cheers Mark

September 15, 2003, 04:01	Re: Absorption Coefficients	#2
Rami Guest Posts: n/a	Hi Mark, The absorption coefficient (in 1/length units) refers to the relative absorption of radiation along the ray path within a participating medium. This is in contrast to absorptivity of a surface (dimensionless). Do you treat the metal as a semitransparnt medium using the Discrete Ordinates? Rami

September 19, 2003, 06:15	Re: Absorption Coefficients	#3
Erwin Guest Posts: n/a	The absorption coefficient of a solid should be set to 0 in Fluent.

September 22, 2003, 08:11	Re: Absorption Coefficients	#4
Mark Guest Posts: n/a	Hi Erwin, Thanks for the advice. Fluent has a default of 0.01 for absorption coeff. for solids. Any comments??? Mark.

September 22, 2003, 09:22	Re: Absorption Coefficients	#5
Rami Guest Posts: n/a	It is possible to have non-zero absorption for solids if they are participating (i.e., semi-transparent). Glass is a straighforward example.

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