Sandia intros revolutionary heatsink with rotating fins

By Matthew · 43 replies
Jul 11, 2011
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  1. Although most of our staffers use aftermarket heatsinks, we rarely cover such devices. It's not because we don't find them useful, they're just boring. The heatsink market has been relatively…

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  2. insect

    insect TS Evangelist Posts: 349   +132

    The simplest ideas...

    Whatever genius was sitting, drinking a beer, and and said, "Hey, what if we spin the fins instead!" is sitting pretty now... or will be (if the technology is cheap enough to adopt into all new electronics).
  3. albertjkruger

    albertjkruger TS Member Posts: 18

    At the risk of sounding nerdy: this has got to be one of the most interesting/fascinating subjects that I've read of today, although I hardly understand how exactly it works.
  4. mailpup

    mailpup TS Special Forces Posts: 7,186   +469

    This is the part I don't get. How can air "efficiently" transfer heat. This gap sounds like insulating dead air to me. Conventional heatsinks need a thermal compound to transfer heat. With no thermal compound and with direct heatsink to CPU contact you still have a partial air gap and the CPU will overheat. How does air now become such a good, efficient transfer medium?
  5. Jesse

    Jesse TS Evangelist Posts: 358   +42

    When can I buy one?
  6. Technochicken

    Technochicken TechSpot Paladin Posts: 729

    How is heat transferred to the rotating fins? It must use some sort of layer of thermal compound, which certainly won't help the cooling efficiency. Also, how does this cut power consumption?
  7. mario

    mario Ex-TS Developer Posts: 399   +17

    Sounds very interesting and it is an area where you don't see much innovation. I would love to see an animation of how it would actually work since it's not 100% clear to me how it works.
  8. There is a stationary baseplate that contacts the processor to transfer the heat. The fans are .001" above this surface and rotating and it pulls the heat from the baseplate

    Phil D.
  9. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,224   +164

    I wonder if these guys said at one point ..."I can't help but think we are missing something" and six heatpipes CL-P0466 CPU Cooler
    I wonder if it's just because cooler components lower the resistance, increase efficiency, and need less voltage?

    As would I. I am interested about what exactly is happening right at the point of heat transfer. It sounds like its different than standard molecular conductivity.....I'm sure that sentence was scientifically incorrect, but you get the idea:p:haha:
  10. TekGun

    TekGun TS Booster Posts: 162   +25

    I wonder how loud this will be, if it outperforms current top end air coolers and is quieter then awesome.
  11. 1977TA

    1977TA TS Rookie Posts: 89

    Wow, these guys are going to make a killing, awesome product!
  12. Puiu

    Puiu TS Evangelist Posts: 2,662   +1,096

    Where did you read that they'll replace the thermal compound? In the diagram you can clearly read "stationary base plate" --> this will come in direct contact with the CPU (with the paste in between). They just replaced the fan+big heatsink with a more efficient way of cooling the heatsink --> they rotate the upper part of it (the biggest part).
  13. dividebyzero

    dividebyzero trainee n00b Posts: 4,891   +1,264

    Takes in ambient (chassis temp) air through the central area, and fires hot air in a 360° spray across the motherboard. Might cool the CPU just fine -at least until the sprayed hot air starts warming up the air volume in the chassis*- but I don't think it's going to be doing the RAM modules, mobo VRM and the back of a graphics card any favours.

    *Going to make chassis intake/exhaust airflow placement a challenge

    / Would have liked to see the lovely diagram use a number higher than 40°C as it's cooling benchmark.

    It's not a hell of a lot different than conventional air cooling according to their pdf. Conventional coolers use a low flow (fan) airstream passing over cooling fins and heatpipes to effect the heat exchange. This method uses a very high airstream moving over those same fins- the same convection (advection?) seems to be responsible for transferring heat from the baseplate/heatspreader, to the fin arrangement -kind of like a turbine effect.
  14. Mizzou

    Mizzou TS Enthusiast Posts: 823

    I don't know, if the fans are turned solely by thermals rising off the processor it's hard to see this being as effective as touted. There's also the issue of the .001" gap tolerance, just about any kind of bump or nudge would probably be terminal ... even dust in the case would be an issue. If a motor is involved (not sure) it would presumably be mounted somehow directly above the processor which would seem to create other problems.

    In the absence of more information or any credible test results it would seem to me that the jury is still out.
  15. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,224   +164

    Good point, going to need a vent/pipe to the chassis exhaust fan.

    OH:eek:, I missed the PDF link.
  16. Vrmithrax

    Vrmithrax TechSpot Paladin Posts: 1,352   +293

    As was mentioned above, there is a tiny gap between the solid mounted baseplate and the rotating fins. The smaller that gap, the better the thermal transfer between the plate and the fins.

    It helps to think of it in simplified terms. Conventional heatsinks conduct the heat away from the source, then radiate the heat away. Conduction is typically highly efficient, but the radiant release into air is less efficient - fans are used to circulate the air and help the efficiency, but the flow is turbulent and less than perfectly even. This new method puts a step in between, by basically radiating from the hot plate across the tiny air gap to the moving fins, which then radiate again into the air. In this case, however, the fins are moving, and look to be designed to keep the airflow very uniform across all fins, so the efficiency of the cooling should be stellar.

    Which brings the power consumption question... If the fins are much more efficient, a slower RPM can achieve the same goal as the old heatsink/fan combination. In theory, of course. Too bad they cant tap that heat energy to generate the spin too, that would be sweet!
  17. dividebyzero

    dividebyzero trainee n00b Posts: 4,891   +1,264

    Intake hole over the centre of the heatsink/fan, shroud to direct exhaust air away and out.......mmmm....kind of sounds like a graphics card squirrel cage.
    Of course the main problem there is that you get a back-pressure buildup on the "sides" that don't vent directly out- which would be an insta-death for a CPU cooler as is described here.

    My main query here is that the centifugal cooler is going to need to be spinning at high rpm (and/or have a large diameter) to cool anything above a mainstream CPU stock clocks. It has already been demonstrated that passive air cooling can effect much the same result. In fact, passive heatsinks can do somewhat better than stock clock/voltage . It actually surprises me that more CPU coolers don't use vapor chamber technology
  18. gwailo247

    gwailo247 TechSpot Chancellor Posts: 2,010   +18

    I wonder how those 50 pages of physics equations are going to stand up against 1 benchmark.
  19. Trillionsin

    Trillionsin TS Evangelist Posts: 1,596   +257

    So tell me.. .how is this possibly immune to dust clogging anymore than any conventional fans?

    If there is airflow, there is a pattern the air will take. If there is air, there is dust. Dust will form on the most susceptible places and then progress just like any other fan/heatsink.
  20. 1977TA

    1977TA TS Rookie Posts: 89


    Seriously though, I can't wait to see some benchmarks/comparisons !
  21. red1776

    red1776 Omnipotent Ruler of the Universe Posts: 5,224   +164

    This is shaping up to where I think they need to call in James Dyson to solve the logistics of it all.:D
  22. Couldn't they do this even more efficiently by leaving the heat sink stationary and sealing a fan right above the middle portion of the heat sink then using the fan to push the air through the fins and out the sides?
  23. yorro

    yorro TS Booster Posts: 251

    This is one of those Why-I-Haven't-Thought-About-It Ideas.
  24. Thermal transfer is done through convection (fluids and gases), conduction (solids and fluids) and radiation (waves like emi). Most heatsinks rely on conduction from the processor into a large amount of metal and then a fan to create convection to remove that energy. Radiation is very small.

    It seems that what they are saying is that this still leaves a non-fluid air barrier which reduces the efficiency of the convection. And of course, the fan itself does not act as a heatsink because of its separation.

    This design seems to be employing convection over a more accurately controlled area and volume of air and that air also acts as a bearing for the fan. The narrow air barrier means there is no dead air so convection is vastly improved (all air has become fluid) and the close proximity of the fan means it can conduct too and becomes part of the heatsink.

    It is all about keeping the air gap tiny and making it behave like a fluid in motion, i.e. a continuously refreshed coolant. Make the air move fast enough with no surface adherence (perhaps just a little turbulence is needed to 'scrub' the surfaces) and it is just like a liquid coolant. It's a brilliant bit of engineering.

    I'm curious to know more about the air bearing - how is it created initially and then maintained so accurately ? What are the surfaces on the bearing like - ultra smooth, channelled, golf balled ? Is there any other bearing involved ? I think there must be one at the centre....?
  25. ALL I can see from this description is errors in the design based around laminar flow, Reynolds numbers and Bernoulli's principal..

    But from a practical pov, the larger mass of the rotating fin assembly will require more torque to overcome the fin assembly's inertia, which means heat output from the motor goes up significantly.

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