Search found 43 matches

by bobo5195
Fri Jul 08, 2011 5:26 am
Forum: The Silent Front
Topic: Spinning heatsink
Replies: 43
Views: 80368

Spinning heatsink

Any thoughts on this http://prod.sandia.gov/techlib/access-control.cgi/2010/100258.pdf From here http://nextbigfuture.com/2011/07/sandias-cooler-technology-offers.html Uses a spinning heatsink by transferring heat across an air bearing (40 nanometer disk) they seem to show that there is minimal ther...
by bobo5195
Fri Jul 08, 2011 5:18 am
Forum: The Silent Front
Topic: Converting AC to DC at the house level.
Replies: 17
Views: 15066

Re: Converting AC to DC at the house level.

This maybe a holy thread revail but just to say i have worked on something like this. It is immentiagley possible in the home. PC power supply would not work so well, maybe a few of them. I am actually very tempted to use one of the PSU we looked at to make a silent PC. Its a 94% Ac to DC conversion...
by bobo5195
Fri Jun 15, 2007 10:32 am
Forum: The Silent Front
Topic: Check out this heatsink analysis software.
Replies: 11
Views: 7378

there is software that models heat pipes accurately. can't remember the name but it used a 1D approach as the writers said that 3D was a pita and did not improve reliability. I would think that external conditions would have an effect in the terms of heatsink cooling. Would also argue that big ass h...
by bobo5195
Thu Jun 14, 2007 10:25 am
Forum: System Advice / Troubleshooting
Topic: Advice on New (Logitech) Mouse?
Replies: 10
Views: 5190

have a VX mouse and use it every day. It is well worth the cash.

Can't fault the responsiveness of the thing but gave up on wired mice years ago.

Got some USBCELL (www.usbcell.com) usb battery things for it so the single battery compartment / battery life is a non issue.
by bobo5195
Sat Aug 05, 2006 2:46 am
Forum: Watercooling
Topic: Any Watercooling components made from non-metals?
Replies: 19
Views: 13059

Admittedly direct die fluorinert is pretty poor but it scales a lot better than normal water cooling as there is less in the way. I believe that cathar said that the storm g7 was doing 137 KW/(cm^2) while I worked out ages back that a direct die fluorinert could do about 50 KW/(cm^2) under similar c...
by bobo5195
Sat Jul 29, 2006 10:46 am
Forum: Watercooling
Topic: Assisted motorless watercooling concept
Replies: 9
Views: 6797

Looking at my old notes velocity is proportional to rayliegh number square rooted. Rayliegh number in this case could be alot of things. It actualy turns out the temprature correlation is a bit more than delta T as the water expands a little (beta) but we could ignore this effect. More importantly i...
by bobo5195
Sat Jul 29, 2006 7:40 am
Forum: Watercooling
Topic: Assisted motorless watercooling concept
Replies: 9
Views: 6797

I don't think linear scale will work as it is more complicated than that by a long way. Probably could work out a relation but for what? processor temp, flow rate. In any case i don't think it will work. Probably could use some equations and such to prove it but that would take to long. Im sure ther...
by bobo5195
Sat Jul 29, 2006 7:23 am
Forum: Watercooling
Topic: Any Watercooling components made from non-metals?
Replies: 19
Views: 13059

flourinert direct die cooling would also work and be cheaper than diamond

Silver is pretty unreactive anyways.
by bobo5195
Sun Mar 26, 2006 3:39 am
Forum: Watercooling
Topic: Water Cooling Tubing/Piping
Replies: 35
Views: 14732

your forgetting the apple water cooled g5's have proper pipes.

HVAC braided tubing is ideal but it is expensive.

There are other ideas.
by bobo5195
Sat Feb 11, 2006 12:29 pm
Forum: Watercooling
Topic: antec p180 & water cooling possible?
Replies: 2
Views: 2697

YES

see google something like antec p180 watercooling

:)
by bobo5195
Thu Jan 05, 2006 4:30 pm
Forum: Watercooling
Topic: Quiet Water Cooling Concept
Replies: 4
Views: 3700

thought this might be of interest, comparing rads on a more highend setup

http://forums.procooling.com/vbb/showthread.php?t=12293
by bobo5195
Wed Jan 04, 2006 3:29 pm
Forum: Watercooling
Topic: Quiet Water Cooling Concept
Replies: 4
Views: 3700

have a look at the bill A graphs, a pa160 performs between a 120 and 240. A few little random thoughts: This setup will work but its all about how temps you are going to get. pa160 is the arguably the best silent rad. there are a few modelers of flow in loops out there that should be able to tell yo...
by bobo5195
Thu Dec 22, 2005 2:56 am
Forum: Quiet Prebuilt, SFF and Barebones Systems
Topic: Sun Fire T1000 Server
Replies: 2
Views: 3023

It wouldnt work well as a standard desktop processor. All the cores are in order and it runs at 1.2ghz (ram bandwidth limited, on a quad channel memory controller!). You can only run it on solaris really due to the load balancing that is required. At standard pc tasks it woudl be slow as anything, s...
by bobo5195
Sun Dec 04, 2005 3:23 pm
Forum: Watercooling
Topic: why not oilcooling?
Replies: 7
Views: 7081

Oils are good and there are many places to use them but your never going to get one that is significantly going to beat the performance of water. As a coolant water is V good and cheap. Oils have a lower thermal capacity per unit mass, per unit volume they are alot better than water i would imagine....
by bobo5195
Fri Nov 25, 2005 3:30 am
Forum: The Silent Front
Topic: Floating Magnetic Bearing
Replies: 6
Views: 4212

One of my lecturers helped invent turbulent modeling in CFD. you can actually solve the problem directly using computers but for all but the simplest problems you wont get an answer before you die. I was talking about dominate effects in an engineering context. While you know nothing about the turbu...
by bobo5195
Thu Nov 24, 2005 6:12 am
Forum: The Silent Front
Topic: Floating Magnetic Bearing
Replies: 6
Views: 4212

Turbulence noise (yes it could also be called wind noise) is actual a complicated function of airflow (my guess is a thrid or 4th order polynomial). As the fan wiggles up and down the flow over it is disturbed causing increased turbulence. Becuase of this tip leakage (Air traveling through the fan, ...
by bobo5195
Thu Nov 24, 2005 4:27 am
Forum: The Silent Front
Topic: Floating Magnetic Bearing
Replies: 6
Views: 4212

A magnetic bearing isnt as stiff as a normal connector so will allow the fan to rattle more in its casing. This means more turbulence noise and a less efficent fan.

I alwasy thought 80% fan noise was turbulence anyway
by bobo5195
Fri Nov 11, 2005 1:48 pm
Forum: Fans and Control
Topic: Bluefront's Fan/Scale Comparitor......DIY
Replies: 40
Views: 15363

gone away thought about it and i still can't get why an orrifice plate would be wrong. You could always use a venturi meter instead but that the same difference. The ASME test rig is clearly using an orifice like meter. flow is low speed = lamina (need to watch for local rough spots and use a lmaina...
by bobo5195
Mon Nov 07, 2005 6:00 am
Forum: Fans and Control
Topic: Bluefront's Fan/Scale Comparitor......DIY
Replies: 40
Views: 15363

similar or exactly the same? The mark is there for a reason. Bear in mind that piezoelectrics give a non linear output so scales can get it wrong (depending on their DSP's, even uber expensive ones can get things wrong). Also because things are dependent on v^2, twice the CFM gives 4x the reading. O...
by bobo5195
Mon Nov 07, 2005 5:00 am
Forum: Fans and Control
Topic: Bluefront's Fan/Scale Comparitor......DIY
Replies: 40
Views: 15363

You know you could make one of those chambers out of standard household stuff, probably would cost as much as the scales. Either way thinking about it now an orrifice plate flow meter is as easy as pie to make, so you could get CFM off that. They dont include the barometer and stuff which you need t...
by bobo5195
Mon Nov 07, 2005 4:14 am
Forum: Fans and Control
Topic: Bluefront's Fan/Scale Comparitor......DIY
Replies: 40
Views: 15363

Piezo eletric stuff produces a voltage for a set displacement. If you load one end and pull up the other (by applying a moment) then you create a shear load. becuase one part of the crystal is in tesion and the other part compression the theory says that you should get 0v ie no load out. Im sure tha...
by bobo5195
Mon Nov 07, 2005 3:21 am
Forum: Fans and Control
Topic: Bluefront's Fan/Scale Comparitor......DIY
Replies: 40
Views: 15363

You are measuring CFM indirectly as you are measuring momentum conservation. Even if your measuring presure thats still related to CFM, non linearly as i pointed out but its still there, would prefer if more back pressure was eliminated though by having a clearer exhaust path and fan further away/ D...
by bobo5195
Sun Nov 06, 2005 5:51 am
Forum: Fans and Control
Topic: Bluefront's Fan/Scale Comparitor......DIY
Replies: 40
Views: 15363

There is way of measuring from the "weight of air" being pushed by a fan but its non-linear and I’m not sure if your scales are accurate enough. The force will be proportional to V^2 due to momentum conservation at low speeds these scales are no going to get it right. Firing the fan at a plate intro...
by bobo5195
Wed Sep 21, 2005 9:47 am
Forum: Watercooling
Topic: Which pump
Replies: 9
Views: 5381

tubing length does play a facotr but in comparison to waterblocks the pressure drop is small if your using 3/8th tubing.
by bobo5195
Mon Sep 19, 2005 12:08 am
Forum: Watercooling
Topic: [Daydreaming] Dual Reserators?
Replies: 12
Views: 6091

right the equations boil down to: C*Q^2 = 40*h(mm) Where c is the resistance of the loop as a constant (m and units of Q). Q is the flow rate and h is the increase in height of the resterator. 5lpm is the max flow of the resterator (max flow in real life it will be less than this but ive done enough...
by bobo5195
Sun Sep 18, 2005 12:54 pm
Forum: Watercooling
Topic: [Daydreaming] Dual Reserators?
Replies: 12
Views: 6091

sorry need to have more of a think
by bobo5195
Sat Sep 17, 2005 2:06 pm
Forum: Watercooling
Topic: [Daydreaming] Dual Reserators?
Replies: 12
Views: 6091

heart analogue is already accepted. The idea of mounting in seris as you desicribe is good from a heat transfer standpoint but the pressure created by a pump generates flow where ever its placed and runign cables in and out of the case is not nice.

some animals only have one ventrical as well.
by bobo5195
Fri Sep 16, 2005 2:01 pm
Forum: CPU Cooling
Topic: Presenting CPU coolers differently in reviews?
Replies: 10
Views: 3960

Im not sure if this is possible or helpful. Cfm readings are hard to do the only reliable way would be to use a duct and take pito tube readings and sum. Their way your looking at about an hour per data point. Secondly fan geometry and heatsink geometeries are different. Some fans may owrk better wi...
by bobo5195
Fri Sep 16, 2005 9:15 am
Forum: Watercooling
Topic: [Daydreaming] Dual Reserators?
Replies: 12
Views: 6091

The restorator will in no way overflow i would not worry about that. even with a huge bad ass pump im not sure that you could get it to overflow. Parallel i would of thought would be far better from an thermodynamics standpoint but i think seris with the two pumps will work as well. For restircitve ...
by bobo5195
Mon Aug 29, 2005 4:03 pm
Forum: CPUs and Motherboards
Topic: Yonah
Replies: 64
Views: 27536

the x86 secert and gamepc test are not inline with many other test run by reputable websites. Examples are anandtech of the top of my head for one. Dothans have a crappy fpu unit and low bandwidth memory interface compared to A64. They definitly show that an oc'd fsb woudl be good for them but domin...