nanofluid!

[STEvil]

relttem - Does the introduction of particulate make the water abrasive at all, or more technically do you know the shape of the particulate added?

My concern is really that the added particulate may have sharp edges which while even being microscopic can eat away at the pump housing, impeller, or any water blocks.

[D_A]

Holy double post Batman!

Good question though.

[relttem]

The concentration of the nanoparticles is not enough to have that kind of adverse effect. So, you won't have anything of that sort happen. You have to remember that these are 10^-9 in size. We had to use SEM/TEM to actually see them. I am not sure your basic micro-scope would even be able to see them..micro is 10^-6.

That answer the question?

[CZS]

I'm sure the particles are no larger in size than the disolved minerals in tap water (probably a lot smaller). Obviously tap water is a no-no for WC, but that has more to do with mineral buildup, reduced thermal conductivity, etc. As long as these particles don't "build up", I wouldn't think that component wear would be an issue...

[relttem]

They are so small that they are *almost* neutrally buoyant. They will settle over time if left unmixed, but a simple shaking will mix them back up. So, if your pump is always going they won't settle, and even if you turn the pump off for a period of time turning it back on will mix them back. We were looking at them under the SEM and TEM to see if there was any agglomeration.

[relttem]

I am just curious to see what the test-people find out

[STEvil]

The concentration of the nanoparticles is not enough to have that kind of adverse effect. So, you won't have anything of that sort happen. You have to remember that these are 10^-9 in size. We had to use SEM/TEM to actually see them. I am not sure your basic micro-scope would even be able to see them..micro is 10^-6.

That answer the question?

Would the size have a polishing effect in that case then? Darn particulate :/

[relttem]

no..to have a polishing agent it has to be more dense. If we made it concentrated enough it would make your pump work harder and slowly erode things, but our density is basically the same as water. So, you won't see anything like that happen.

[STEvil]

Abrasion is not about density though.

[D_A]

Just have to wait for some test results I suppose.

[relttem]

Abrasion is not about density though.

there are not enough nanoparticles in the fluid for it to be abrasive. Thus, the density of the water is unchanged...how about that? If we put a lot of nanoparticles in the fluid, the density would change and the fluid would be more abrasive..sort of like puting one grain of sand in a cup of water versus 100,000 grains.

[[486]]

The one grain of sand would still be abrasive, but the nano-particles might be light enough to get out of the way of the impeller blades from the thin film of water that is traveling with the impeller [I'm figuring surface tension has something to do with it... just thinking of how it seems it might work... you know?]

[relttem]

one grain of sand in a cup of water would be abrasive...true..but, it would be many magnitudes of order less abrasive than 100,000 grains of sand in a cup of water...so, if water's abrasive measurement is 100..our nanofluid mixture abrasive measurement is barely higher ~100.00001. We ran our nanofluids over a painted, heated flat copper plate at Reynolds numbers up to 500,000. The Reynolds number gives the ratio of inertia (velocity and density) and viscous (viscosity) forces. We ran different concentrations at different speeds and noticed no abrasive effects on the painted plate. Now, the laser we were using for PIV and PLIF burned the paint. If water is chewing up your impeller then the nanofluids will too. Being almost neutrally buoyant the nanoparticles are going to follow the stream lines going thru the pump - basically just following the flow. If it were abrasive it wouldn't follow the streamline; they at actually drag along the surface - thus the abrasion. A phenomena called 'the boundary layer' is developing around the impeller blades as they spin. The stream lines follow the boundary layer thickness with the nanoparticles following the streamlines. Make sense? - it is hard to explain without drawing it.

[Jaivan]

wow cool stuff really looking forward to some results!!
sub'd

BTW reynolds number of 500000!! How long and what temps was the plate at? because that some pretty fast moving water haha.

[relttem]

yeah, that water was flying thru the test section. When it was wide open it was actually scary. It was a 5hp pump - If I remember correctly it could pump 50gpm. The test section was 2x2 inches, with a 9-3/8inch plate. I think we were measuring halfway down. It pumped so fast that we had cavitation, and it put so much heat into the fluid that we had to put the fluid thru a cooling section to prevent it from boiling (and to keep the temperature of the fluid constant). There were a few times we forgot to turn that on, so I know how hot that water can get. We pressurized the loop to kill the cavitation.

[xtclocker]

Hello relttem, this is safe to use with acrylic based materials?

[relttem]

acrylic based materials?..like what? We would have to test the ph, but I am pretty sure that it is neutral. It is a lot of water, and if I remember correctly water doesn't bother acrylic paint after it dries. I would have to have more information on what you are doing with it.

[D_A]

I think he's referring to the acrylic used for the clear tops in a lot of water cooling components, like the CPU blocks etc.

[relttem]

our test loop in the lab was made out of clear PVC and a GE untra clear Polymer..we didn't have any problems with those..and, we sent the samples out in Aquafina 1litre bottles.

[relttem]

We got the stuff out to another person on here and to a guy at Tom's Hardware on Friday..results should be soon..

[karl_eller]

You couldn't have picked someone better than Tom's Hardware? They haven't exactly been the most accurate reviewers in the past while

Eller

[relttem]

Three people on here, a guy at Tom's, and a guy at Anandtech have samples. We got kicked off the MaximimumPC forum and they deleted our thread..it was sort of funny, but I recommend you NOT mention nanofluid on their forum. I am hoping soon for the review. I know the Tom's guy said it might be a week or two. Anandtech has had it for a few months..I have no idea what is going on there. And, the three guys here pretty have only recently got it with Littleowl reporting back...

[karl_eller]

Why was the thread on MaximumPC deleted? Any particular reason?

Eller

[relttem]

they thought we were full of ...those were their exact words as a matter of fact

[D_A]

I would have thought that sort of judgement should have waited till after a proper assessment of the product.