CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Emissivity’s dependence on thickness?

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   July 1, 2013, 09:36
Default Emissivity’s dependence on thickness?
New Member
Join Date: Jul 2013
Posts: 4
Rep Power: 4
Jerry Pham is on a distinguished road

I'm completely new to CFD and would like to ask some entry-level questions:
In some flow simulation softwares they usually requires specifying emissivity for surfaces, such as in Solidworks Flow Simulation this might appear as:

but there is a question on the exact definition for this: it ϵ thickness-dependent?
According to
Although it is common to discuss the "emissivity of a material" (such as the emissivity of highly polished silver), the emissivity of a material does in general depend on its thickness. The emissivities quoted for materials are for samples of infinite thickness (which, in practice, means samples which are optically thick) — thinner samples of material will have reduced emissivity.

Most emissivities found in handbooks and on websites of many infrared imaging and temperature sensor companies are the type discussed here, total emissivity. However, the distinction needs to be made that the wavelength-dependent or spectral emissivity is the more significant parameter to be used when one is seeking an emissivity correction for a temperature measurement device.
I wonder in doing the calculations, does Solidworks (and other more sophisticated software) make any adjustment according to the actual thickness of a surface?

Attached Images
File Type: jpg emissivity.jpg (13.2 KB, 5 views)
Jerry Pham is offline   Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Momentum and displacement thickness: du/dy calculation Josh CFX 13 October 27, 2013 15:38
Question about momentum thickness Reynolds number Anna Tian Main CFD Forum 2 March 4, 2013 11:45
Total Thickness of Inflation Layer prikeyma CFX 3 February 12, 2013 04:19
Questions about Boundary Layer Thickness and Turbulence Models famerfamer STAR-CCM+ 3 July 12, 2012 09:47
boundary layer thickness 98.4F Main CFD Forum 1 December 29, 2000 08:23

All times are GMT -4. The time now is 01:43.