...would be interested in this I bet. Looks like something they would feel comfy with.
A US government lab has opened for licensing a novel way of improving the cooling technology used in everything from CPU and GPU coolers to air-conditioning units: make the fan the heat sink, and the heat sink the fan. "We describe breakthrough results obtained in a feasibility study of a fundamentally new architecture for air …
That's pretty nice. I wonder if ducting or tubes will be part of it. But, if anyone is thnking of getting patent-crazy, a possible workaround/defeat could be similar to what Dell and others do: put a fan at the chassis opening and a fan near the heatsink, and choose directions of cooling and exhaust according the the final internal arrangement. Maybe tubed, axial fans might work, too...
It's already been thought off! It's called a "flywheel". Take a look at any two cycle weed eater, it has the basic engine that's producing heat, and a flywheel that produces energy to fire the ignition, but at the same time, absorbs heat and cools the engine via forced air. Most are made of cast aluminum. The trick in his quest is to get heat to transfer from the block underneath to the "fan" itself. There is a tradeoff on large fins to absorb heat verses how much air you can push through to cool efficiently. A sweet spot, if I may.
Next will be a magnet inserted on the end of the 'fan" and some type of pickup to either power something internally or monitor RPMs.
...it's one where everyone will say "I could have thought of that".
The really clever bit is in the thin air layer. Sure, air is normally a terrible conductor of heat, but when the layer is so thin it's thermal resistance is much reduced*. Thus, from the the point of view of the heat, the rotating impeller is thermally 'attached' to the base plate (or at least much more so than if it were, say, 1mm away).
I for one hope he/they make a pile of cash out of that. Clever ideas like that need rewarding. And besides, something like that spinning away at several thousand RPM has got to sound just a little bit like a turbine, and that'd be a cool noise for any PC to make.
There must be a pile of kinetic energy built up in that spinner. That could be used as a little energy reserve; lose the mains power, and the spinner becomes a generator providing just enough electricity for a cleanish shut down. Bit like an F1 car's KERS. My idea (unless someone else thought of it first)!!!
*Just like metal loaded epoxy used to connect some flexy circuits; it's a terrible conductor over any sizeable distance, but when used in thin enough layers that doesn't amount to much.
It is not the "thin" or at least not "just the thin".
The heatsink is spinning and there is a constant shear across that micro-gap. So its heat conductivity will _NOT_ be the conductivity of an air gap at rest with the same width.
What is it going to be - god knows, but my educated guess is that it will be more. In fact much more. That is the trick here. The thing works so well because of conductivity across a disturbed boundary layer which is being kept in that condition by the heatsink spin. At a couple of thousand RPMs it is likely to be on par with a lot of heat transfer pastes.
I did not get it on first reading either by the way. I looked at it, thought WTF and only after an hour it hit me: "This is what this guy has done".
Clever, definitely much more clever than it looks. One thing is clear however - this is not Zalman material. At the speed where the layer is disturbed enough for it to work it will produce noise higher than Zalman tends to accept in their gear.
"The thing works so well because of conductivity across a disturbed boundary layer which is being kept in that condition by the heatsink spin. At a couple of thousand RPMs it is likely to be on par with a lot of heat transfer pastes."
Yes, I think that's a far better explanation of what's going on. It's better to move the heat by moving and constraining the air, rather than rely on the heat conducting through the air.
I still wish I'd thought of it!
sorry, been done. Is used on (some? all?) disks so when power's cut the motor becomes a jenny and makes enough elec from disk running down to complete a (typically 4k) sector write, and I guess park the head after.
So I understand anyway.
Indeed, but that powers only the harddisk. I was thinking of the whole machine, or at least enough of it to close a few files properly. A VME chassis has an ACFAIL line, which can be used in embedded applications to do some vital stuff in the dying microseconds of the PSU's capacitor charge; quite a useful notification in some circumstances!
I thought that head parking was achieved through purely mechanical means in that the forces exerted on the head (via the air cushion) by the spinning disk have a tendancy to push the head arm off the disk. But there's clearly enough energy in the disk to do it electronically too.
Just a thought - that's not something that SSDs can really do is it, unless they have a decent amount of capacitance somewhere. So is a power cut a slightly greater problem with an SSD than for a HDD? Whatever volume checking an OS performs after a power loss, it'd be much nicer to find that all the sectors had been correctly written.
HDD heads nowadays auto-park because they're on a spring an voice-coil arangement which -- the power is cut to the positioning voice coil and spring returns the head to the centre.
Wasn't always like this though -- old HDDs were on stepper motors so the head had to be manually "Parked" if hte PC was to be moved, to stop it dragging across the platters. I miss the thunk of my old AT's head parking...
@bazza "I was thinking of the whole machine": Just how much mass do you think this heatsink has? From the picture, it's no where near the mass required to harvest kinetic energy to power a complete rig. Perhaps if it was on the order of Scythe's Mugen R2, then you might be able to help an SSD clear its cache (Intel SSDs and the like, since Sandforce doesn't use DRAM caches). But to help the whole machine, you're looking at several kilos at the least.
What happens when some idiot moves your PC whilst it is turned on so they can get something that has just fallen down the back, that sub-mm air gap will suddenly become much closer to the thing you're trying to cool and is likely to come whizzing out the front like some manic kung fu style star (except a lot hotter)
Angular momentum or some such physiks (or magic, much the same)
... because they are sealed units made in a clean room. This fan will not clog up because - erm err (wave hands a bit) some really clever reason. The close tolerance between the heat sink and fan narrows the boundary layer around the heat sink at the cost of extra air resistance. There will still be a boundary layer around the fan. If they still shift more heat per watt running the fan then cool.
cool air is pulled into the centre of the fan and "comes into contact with the hot base plate" so I think the air gap is exposed to fresh incoming air, full of dust. Hard bits of grit then get into the tiny close-tolerance gap and start grinding away the metal, producing a fine conductive dust that supercharges your RAMs. Ok I don't fully understand the concept yet.
These f**king flash adds are lagggin my interwebs. Why you have such yucky adds Reg? I don't run ABP on your page because I actually think you deserve the revenue but if you keep this up... You know flash adds actually put me off wanting a product? I don't care about boats and don't even know what it's for.
Im very keen to put a large, presumably heavy and necessarily sharp edge spinining flywheel right next to my graphics cards. on top of my chip. next to my ram.
several thousand RPM, you say? That's... thats astounding. like a chainsaw, then?
In all seriousness it sounds like a good idea, but the market is increasingly moving away from fanned systems to either passive-cooled radiators in massive tunnelled racks for business, and sealed-system liquid coolers in home units. personally I still want a total-immersion/submersion cooled beastie at heart. With lights! and bubbles! anything to seal the box, really.
Humans are dirty, and there's no way to avoid crud and the associated thermal problems with crud unless you make the computer a sealed unit (with a rad on top. or machine the entire backplate out of copper, mebbes)
take a look at the latest gfx cards. apart from the ones with liquid cooling blocks on they all have fans. only the nasty cheap cards are fan free. enjoy your low res/detail gaming with those.
liquid cooling is still more expensive than it should be. maybe all PCs should be liquid cooled and the costs would plummet?
there are also instances of when liquid cooling pumps die and your pc fries. im not sure i would trust a £100 to not die and fry £1000 worth of GPU/CPU etc.
The wire safety cage is an eminently sensible component - if only to avoid a Darwin Award following on from some unforseen event.
Good engineers need to survive to complete their good engineering.
It reminds me of one of the best engineering team of the 20th Century - the Wright Brothers. They realised that powered flight could be dangerous so they put the engine along side the pilot so that if there was an accident the pilot would not hit the engine - or vice versa.
There are some good questions needing good answers.
I was sceptical, but many questions I had are answered in the 40+-page paper.
E.g the PC heatsink is 0.2C/W vs three or four times that for a similarly sized classical one.
The question re junk in the bearing remains largely unanswered. The demo unit used lab-standard helium or nitrogen to pressurise the air bearing; p 25 "The use of dry nitrogen, rather than air, is an experimental convenience.". Well some readers will need more convincing than that, though he could well be right (maybe the thing is self cleaning? Really?).
Heatsinks do 2 jobs:
1 provide a conduction path to lose heat to the environment.
2 provide thermal mass to buffer rapid temperature changes
There's a little problem with this design, if the impeller stops spinning, the air gap becomes an insulator and suddenly the thermal mass is no longer connected to the thing it's buffering and cooling....
The bulky heatsink on modern processors doesn't need fan driven airflow a lot of the time, coupled with the thermal inertia that makes them relatively failsafe. 10s of seconds with a failed fan before dangerous heat levels are reached is not unusual, more than enough time for the CPU, OS or user to take action.
However effective this design is, he'll have to cripple it with old style passive blocks of metal to make it safe to use. That might restrict its market a little, if you've got to put the hefty metal in there either way there's not much point replacing the cheap fan on most systems.
...and I don't believe the dust claims. My desk fan seems to have no trouble covering it's spinning blades in dust... neither do the fast spinning ones in my PC.
Is the lack of thermal contact - the air gap is a significant and inevitable barrier to proper conduction. Those 'fins' on the impeller are *not* equivalent to the stationary fins on a normal heatsink because they are not bonded to the chip with a thermally conductive paste.
All he's really done is get rid of the heatsink entirely (except for the aluminium plate) and put a faster fan right next to the chip. Bravo.
That's a bit of an understatement. The highly turbulent (and thin) air layer should be a *much* better conductor of heat (orders of magnitude over still air). A question would be why does it have to be so *tall*?
The real question is does novel ==better?
I for one welcome our new rapidly spinning, sounding like an idling gas turbine cooled overlords.
The writer's description of how a conventional heat sink / fan combo works is completely backwards.
The article says that the finned block of metal's job is to draw heat out of the passing air.
No, not at all.
The CPU (or other component) generates, relative to its actual mass, immense amounts of heat (seriously: in some cases over 100W from a layer a few microns thick of doped silicon), and this heat is conducted to the hunk of metal. The heat then leaves the hunk of metal *into* the air, which is moved away either by convection, or if the heat burden is high enough, by a fan.
(yes, I know about heat pipes; all they do is move the hunk of metal away from the heat source. the actual heat sink is still cooled by moving air.)
is, I believe, to be read as "fins that dissipate, in the air, the heat contained".
If the author really believed the heat was sucked from the air into the sink then into the CPU, ... I guess we'd have noticed other strange things in the article. Don't assume people are that dumb.
1 its an impeller. we have had impellers before they are not dust and crud proof. the dust and crud collects on the inside centre and blocks the vanes.
2 Impellers generally spin faster and are hence very whiny from the impeller vanes not the bearings! (gigabyte made a cpu cooler a couple of years ago it lasted about 3 days in my rig).
3 This test is mains powered!? of course its going to be a powerful cooler! but will it work as well when scaled back to pc 12v and lower amps?
4 Air gap, all well and good in a lab now air gap meet smokers tar residue and cat maltings.. the end.
5 Air gap (ii) and thermal insulation are two terms that go well together air gap and thermal transfer are not! whilst a sustained heat source will permeate an air gap at a constant and sustainable rate, I believe that a rapidly changing heat source such as a cpu will suffer with excessive lag in the transfer responsiveness. so much so that a rapidly increasing core temperature would spike the base block temperature massively before the thermal transfer over the air gap can wind up to full capacity.
6 Boundary Layer. This device offers nothing new, it might be a carefully designed shape to reduce static air (not boundary layer effects) but this is also possible in traditional systems as sold by companies like Zalman BUT specialist shapes are often more expensive to manufacture hence we still have the cheap "it'll do" extruded aluminium squares, as the cost to effectiveness break point is adequate. is this device offering us cheaper efficiency? I doubt it.
7 High speed airflow, well because of the very high rpm this device generates a very high speed airflow which can reduce the thickness of the boundary layer, but this high speed airflow can be achieved in standard designs also, but at the expense of power (and psu heat) and silence!
These days PC's are going for larger quieter fans pushing big slow volumes of air, for good noise levels, This design is counter to that tack in all ways and has not been shown to offer any advantage on this consideration.
So will these work? well maybe in specialist no expense spared, dust sealed noise isolated kit.. but I don't use much of that.
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