optical thickness

ehrenwirth · June 25, 2009, 11:21

Hey there!

If you simulate radiation, u need to know the so called optical thickness. Can someone help me with this? For example i want to calculate the optical thickness of a air-film with 10mm thickness.

Thx a lot!

ckleanth · June 25, 2009, 17:22

google wiki optical thickness air

ehrenwirth · June 26, 2009, 10:07

Hi!

I searched google up and down and found nothing, thats why i asked my question in this forum! By the way the first entry in google is this post in this forum here ;-).
Can you gibe me better tipps?

Thx a lot!

ckleanth · June 26, 2009, 10:27

Quote:

Originally Posted by ehrenwirth

Hi!

I searched google up and down and found nothing

eh??

http://en.wikipedia.org/wiki/Optical_depth

I think you'd probably need to visit your university library borrow a physics book and read it. especially the bits that refer to wavelength

Quote:

Originally Posted by ehrenwirth

air-film with 10mm thickness

ehrenwirth · June 26, 2009, 10:59

Quote from Wiki:

"One way of visualizing optical depth is to think of a fog. The fog between you and an object that is immediately in front of you has an optical depth of zero. As the object moves away, the optical depth increases until it reaches a large value and the object is no longer visible."

Means air always has optical thickness of 0? I just wonder about the fact that in this forum so many people simulate radiation and the optical thickness seems to be the significant parameter to choose the radiation modell. So there must be a paper where you could get those values. but i dont find anything...why?

ckleanth · June 26, 2009, 11:36

before even touching cfx you need to understand the basic principles and what you want to do.

here's a link to read as I still think that you have some more reading to do

anyway in cfx there are a few different radiation models to chose from. the manual has all the information you need to describe how these radiation models work.

June 25, 2009, 11:21	optical thickness	#1
ehrenwirth New Member Join Date: Mar 2009 Posts: 21 Rep Power: 17	Hey there! If you simulate radiation, u need to know the so called optical thickness. Can someone help me with this? For example i want to calculate the optical thickness of a air-film with 10mm thickness. Thx a lot!

June 25, 2009, 17:22		#2
ckleanth Senior Member George Join Date: Mar 2009 Location: Birmingham, UK Posts: 257 Rep Power: 18	google wiki optical thickness air __________________ Top 4 tips 1. Knowledge is everything and Ignorance is dangerous. 2. Understand your limitations and try to eliminate them. 3. Get yerself a bike and hoon the chuffer. You will soon learn why dogs like to hang their heads out the car window. 4. Please before asking any questions on how to run simulations in CFX, go though all the tutorials

June 26, 2009, 11:36		#6
ckleanth Senior Member George Join Date: Mar 2009 Location: Birmingham, UK Posts: 257 Rep Power: 18	before even touching cfx you need to understand the basic principles and what you want to do. here's a link to read as I still think that you have some more reading to do anyway in cfx there are a few different radiation models to chose from. the manual has all the information you need to describe how these radiation models work. __________________ Top 4 tips 1. Knowledge is everything and Ignorance is dangerous. 2. Understand your limitations and try to eliminate them. 3. Get yerself a bike and hoon the chuffer. You will soon learn why dogs like to hang their heads out the car window. 4. Please before asking any questions on how to run simulations in CFX, go though all the tutorials Last edited by ckleanth; June 26, 2009 at 19:37.

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June 26, 2009, 10:07		#3
ehrenwirth New Member Join Date: Mar 2009 Posts: 21 Rep Power: 17	Hi! I searched google up and down and found nothing, thats why i asked my question in this forum! By the way the first entry in google is this post in this forum here ;-). Can you gibe me better tipps? Thx a lot!

June 26, 2009, 10:59		#5
ehrenwirth New Member Join Date: Mar 2009 Posts: 21 Rep Power: 17	Quote from Wiki: "One way of visualizing optical depth is to think of a fog. The fog between you and an object that is immediately in front of you has an optical depth of zero. As the object moves away, the optical depth increases until it reaches a large value and the object is no longer visible." Means air always has optical thickness of 0? I just wonder about the fact that in this forum so many people simulate radiation and the optical thickness seems to be the significant parameter to choose the radiation modell. So there must be a paper where you could get those values. but i dont find anything...why?