Actually you don't even need maths; common sense and a knowledge of the meaning of ordinary English words (or the ability to read a dictionary) is sufficient.
Supposing I wanted to use a heat pipe to heat a cup of tea by dipping one end in the cup and heating the other end (gently!) with a blowlamp - would that be dissipation? Of course not.
-- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
They are not all that far off the ideal behaviour though. An order of magnitude better conductivity than a metal like copper or aluminium.
A vapour phase transition can move a lot of energy from the hot end to the cool end and then wick back along the walls to repeat the cycle.
Graphene heat pipe only real advantage is lighter weight and "coolness". (as in novelty value - horrendously expensive for what it is)
There is a tendency for graphene with everything at the moment.
-- Regards, Martin Brown
Its other advantage is fragility (from the makers' perspective). It don't dent or bend so good.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Well, you at least need some arithmetic to estimate how hot the chip will get. You need to buy the right heat sink, and maybe fans.
There is an interesting quantitative analogy between thermals and electricals:
ELECTRICAL THERMAL
1 amp 1 watt 1 farad 1 gram aluminum 1 volt 1 degree C 1 second 1 second 1 ohm 1 K/wattwhich is accurate to about 10%. So you can use Spice to analyze either static or transient thermal systems.
Not according to my use of the word.
I like to bench test things as a sanity check.
-- John Larkin Highland Technology, Inc The best designs are necessarily accidental.
There are material fads in academia.
They used to corrode internally and fail. Are they better now?
-- John Larkin Highland Technology, Inc The best designs are necessarily accidental.
They're used in the heatsinks of most of the servers in the world AFAIK. I've had six of them running in Supermicro boxes for a decade or so; one running 24/7.
Copper and distilled water is a generally benign combination, and of course you can use Prestone if you want oxidation inhibitor. Aluminum may not be so good.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Sanity-checking the lunatic fringe. ;) Tinfoil hats recommended.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Fun, and potentially useful. Mind if I put it in my revised thermal chapter?
So you can use Spice to analyze either
At least in situations where diffusion isn't important. When diffusion matters, you get an extra 45 degrees' phase shift every time your amplitude goes down by 1/e, without limit. Using PID control in a diffusion-dominated problem is not a growth strategy.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
No, please do. I think it's about right. Of course, thermal systems are seldom so polite as to be made of lumped elements.
I haven't had time to review your draft. I've been crushed, and fatigued from what was probably The Virus. I'll try.
A string of R-Cs sorta works some times. Or an LTL.
In lieu of buying and learning serious software, I bench test. Do some machining and get away from mice and screens for a while.
-- John Larkin Highland Technology, Inc The best designs are necessarily accidental.
Thanks. I'll check before I do, obviously.
Sure, no worries. Hope you feel better soon. The book will be in production for some months, and I can fix mistakes up till the fourth printing, so Christmas isn't really a drop-dead date.
Yup. Uber-fancy simulation software is a full-time job to keep up with. That's mostly what keeps me away from Comsol or LightTrans or those sorts of things.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
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