Wikipedia:Peer review/Heat sink/archive2

Heat sink

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I've listed this article for peer review because I have made a major revision of the article.

Most of the article is new except the following sections: 3.3 Firestopping and fireproofing, 3.4 In soldering. "Firestopping" does not have any references and soldering only has one. The aforementioned are not my area of interest.

There were only two references in the original article. And those references were not applicable to the parts specific to heat sink, as far as I can remember.

The rest of the article is "new", well referenced and, in my opinon, logical. I had initialy put the section "4 Methods to determine heat sink thermal performance" in the beginning of the article, but decided that some people are not interested in that. So, to keep their interest, I put it at the end of the article.

I still want to add the following, but want to wait on peer review the changes made so far before putting more effort into it.

Something about emmissivity of surfaces (their effect on the performance of heat sinks)
More on LED heat sinks
- The articles that I have referenced to are good, but I need to sort out the copyright issues. See "Image use under "Copyright designs and patents act 1998" in editor assistance.)
Heat sink testing
- Same issue as previous.
Bypass flow
- Same issue as previous. Need photos of literature...

Anyhow.

Thanks, Dtc5341 (talk) 10:23, 26 March 2010 (UTC)[reply]

I made some minor tweaks to the intro, such as removed the in-line disambiguation already taken care of by the hatnote. while the intro introduced what is to be discussed in the article, this should in the form of a summary not explicitly with statements such as: (Such-and-such will be discussed in this article...) See: WP:LEAD.--Supertouch (talk) 15:12, 26 March 2010 (UTC)[reply]

I have revised the introduction. Dtc5341 (talk) 13:48, 30 March 2010 (UTC)[reply]

Notes by NVO

(NB. I'm a wafer designer by my first trade although in the last twenty years I only indulge in tube stuff as a hobby.)

Lead: controversial statements.

"a finned metal object". Not necessarily finned. The device may be bolted or clamped to a perfectly flat enclosure wall.
- Change to "object". 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
"The term heat sink is never used in a heat transfer text book". Usually it is (example: Advanced thermal design of electronic equipment) - or did you mean some specific college course?
- Most academic books (e.g. Incropera, Mills, Cengel) that discuss that discuss heat transfer generally and not specifically for electronics cooling like your reference. A reference that I use, Sergent and Krum, ... I do not know what they say. It is reference able quote. Will rewrite though. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
  - Updated this section to refer to specifically text books which discuss heat transfer in general and not specific electronics cooling. Dtc5341 (talk) 13:48, 30 March 2010 (UTC)[reply]

Basic sink heat transfer

If you define heat sink function as a process that ultimately dissipates energy into a fluid medium, perhaps you should clearly say that the article excludes cooling in vacuum (satellites, tube plates) or the conditions where fluid medium exists but is physically too far to be of any worth.
- Will include radiation and mention vacuum. Dtc5341 (talk) 13:48, 30 March 2010 (UTC)[reply]
Conclusions of this section are valid only for continuous energy flow. It must be clearly stated. Short pulses and short duty cycles are a different world where "parallel universe" actually makes sense.
- No it does not make sense. What you are talking about is the thermal transient capacity of a heat sink. A short pulse still dissipated energy into the object (heat sink) and then into the surround air or fluid medium. The energy is still there and does not disappear, nor does it go to a "parallel universe". Transient energy balance. Ein - Eout = dE/dt or something like that. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
- This article discusses specifically heat sinks to air. Energy dissipated into a block of copper still is conducted in the material. Dtc5341 (talk) 09:06, 29 March 2010 (UTC)[reply]
"Air always flows upward" - please emphasize that this is relevant only for stationary devices (not vehicles). It is not obvious right now.
- Will rewrite. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
  - Have rewritten. Dtc5341 (talk) 13:48, 30 March 2010 (UTC)[reply]
"Fourier was a French mathematician (1768 -1830) who made..." - redundant, there's Joseph Fourier.
- Corrected. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]

Design factors

"Copper is .. around 4 to 6 times more expensive" - remove price comparison, prices are too ... fluid. :)
- I agree that the price comparison is "fluid" but it a "fact" that at this moment in time, aluminium is cheaper than copper. Copper is quite expensive to mine and is not environmentally friendly mining process. Please refer to http://www.basemetals.com/ where at the 26 March 2010, 10:14 CEST, the price of copper is 7490.5 USD per metric tonne, while for aluminium it is 2200 USD per MT. So, not 4 but 3.4. The point that I am trying to make is that the copper price, market dependent ofcourse, is more expensive than aluminium. I will keep the reference, but add that it is market dependent. Will add some historic data from London Metal Exchange for the last 5 years. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
  - Updated. Dtc5341 (talk) 13:48, 30 March 2010 (UTC)[reply]
"A pin fin heat sink is a heat sink that has, well, pins on its base" ... "street talk" - refactor appropriately for an encyclopedia. Same concern for most of the text: it reads like a recording of a spoken lecture, at times patronizing.
- I have change the street talk to "It is generally considered that the more surface area..." 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
- Removed the ",well,". 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
"Kordyan [1] has compared the performance..." - are you confident that the cited statement can be taken for a general rule? "straight fin heat sink of similar dimensions" - please confirm that indeed they meant "dimensions" and not surface area. Sounds counteintuitive.
- I will add the specific dimensions of the heat sinks in a table form to the article. And the point that the author (Kordyban) is making is that although pin fins have a large surface area, it can not be effectively used if there is too much flow resistance in between the fins. Very little flow results in low heat transfer coefficient, higher average local temperature of the air and the net result is a heat sink that performs poorly. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
"Opening up the fins: Increases the hydraulic or effective diameter." - what is it, in plain language?
- I will have to get a method of explaining this. Will get back to this. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]
"The net result is a heat sink that has a lower thermal resistance than a straight fin heat sink." - needs a common metric ("of the same surface area", "same mass", "same overall dimensions"). I suspect they meant "of same surface area and the optimal profile for each type, regardless of overall dimension".
- Put in a quallifier. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]

Engineering applications

Section heading "Attachment methods" disquises the fact that all listed methodes are for consumer microprocessors only. If you don't plan to discuss other uses (like industrial power switches or UHF transmitter devices) then I'd recomment removing this heading.
- True. But if you look at the section that it is in, it is in the Processor/mircoprocessor section. Look at the structure of the article in the table of contents as shown below. I do not hide this. 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]

3 Engineering applications 3.1 Processor/Micro processor cooling 3.1.1 Attachment methods 3.1.2 Thermal interface materials 3.2 Light emitting diode lamps

- I have changed the heading to "Attachment methods for the processor and mircoprocessor market". 83.163.169.225 (talk) 09:04, 29 March 2010 (UTC)[reply]

Firestopping and fireproofing

I recommend removing the whole section. The fact that pass-through pipes decrease efficiency of a firestop is irrelevant to the function declared in the lead or in "Basic heat sink transfer section." Stick to electronics; you cannot possibly list all thermodynamic issues of the world in one article.
- Want to wait a bit before deleting this section. It is not my work, but it also does not have good (any) references. Dtc5341 (talk) 13:48, 30 March 2010 (UTC)[reply]

Missing

I recommend discussing design rules for heatsinking (i.e. "Heatsinks are Bad, Fans are Far Worse") considering reliability and design life.

Regards, NVO (talk) 20:50, 27 March 2010 (UTC)[reply]

I have noted the changes requested and will during the first half of this week make corrections. Dtc5341 (talk) 05:58, 29 March 2010 (UTC)[reply]

Comments by Spinningspark

Nice job, I do not have time to do a detailed, picky review, but overall I get an excellent impression of a good article. The major omission would seem to be that the applications still concentrate heavily on processor heat sinks. Heat sinks on mechanical machines are hardly mentioned, although this is a common application on all sorts of machines, including motorcyles. In fact, a heat sink does not necessarily consist of a finned lump of metal, in terms of heat engines it can be a large pool of water. Even in the field of electronics I do not see mentioned the very common practice of providing small heat sinks for power transistors. Dummy loads will also usually require them.

I also picked up in a few places the article reading as if it were teaching students not to make mistakes in their design and directly addressing the reader. This is not the right tone (or purpose) for an encyclopedia: state the facts in a passive voice and leave the reader to draw conclusions. Again, I have not produced a detailed list for you but I made one or two edits on this score.

Once again, nice job, that is more than a x4 expansion and nearly qualifies for DYK, quite an achievement for an article as big as 11kB. SpinningSpark 08:23, 4 April 2010 (UTC)[reply]