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Subject: Re: THERM convection coefficient as a function of
Author: Tom Davis
Date: 2002-09-30 10:56:00

As a further note on this that may be of interest, I found that if you are
dealing with natural convection to cool a device that is in the range of 75
F or more above ambient, then you are really not using natural convection.
40-60% of the cooling will likely be through radiation.

Now, before anyone starts to nitpick my numbers, just consider this a rough
rule of thumb and be aware that when you were taught in college to ignore
radiation in most cases, they are exceptions and this is one of them.

TWD

Thomas W. Davis, P. E.
FSI International (http://www.fsi-intl.com/)
3455 Lyman Boulevard
Mail Station 4-1035
Chaska, Minnesota 55318
PHONE 952-361-7359, FAX 952-361-7393
tom.davis@f...

|---------+---------------------------->
| | "Jose L. Torres" |
| | | | il.uh.edu> |

| | 09/30/2002 09:31 |
| | AM |

|---------+---------------------------->

| To: xansys@yahoogroups.com

| cc:

| Subject: Re: [xansys] Re: THERM convection coefficient as a function
of |

Christopher,

You're right, maybe I shouldn't have said efficient cooling. In our lab we
have
been able to cool silicon membranes that have 5mW/cm^2 heat on it by pure
radiation.

Jose Torres
Department of Electrical and Computer Engineering
University of Houston
Houston, TX

At 06:32 PM 9/27/2002 -0500, you wrote:
>>We use this type of
>>cooling in our lab all the time, and the cooling is very efficient.
>How much heat flows by radiation? I got into this briefly in a past life
>and I've always had the impression that free molecule flow wasn't a very
>efficient heat transfer mechanism. This is only a curiosity question, not
>a comment--it's always nice to check up on things that I may or may not
>remember correctly.

>Christopher Wright P.E. |"They couldn't hit an elephant at
>chrisw@s... | this distance" (last words of Gen.
>___________________________| John Sedgwick, Spotsylvania 1864)
>http://www.skypoint.com/~chrisw
Posts possibly associated with message #42301AuthorDateScore
42256THERM convection coefficient as a function of pressureJose Torres2002/09/27 
42262Re: THERM convection coefficient as a function of pressureEdmund Singer2002/09/27 
42265Re: THERM convection coefficient as a function of pressureJose Torres2002/09/27 
42266Re: THERM convection coefficient as a function ofChristopher Wright1969/12/31 
42298Re: THERM convection coefficient as a function ofJose Torres2002/09/30 
42301Re: THERM convection coefficient as a function ofTom Davis2002/09/30