| Friday, January 25th 2008 |
Sound waves can boost the efficiency of liquid cooling techniques by nearly 150%, a feat that may help keep hardworking computer chips and other components from overheating in future. Current computer cooling solutions, such as fans and heat sinks, will have difficulty keeping more powerful microchips cool in future. But researchers in the US have shown how a relatively inefficient method – liquid cooling – can be improved dramatically with the use of sound waves.
One of the best ways to remove heat quickly in high-power applications is to allow a liquid coolant to boil, so that the resulting vapour whisks away excess energy. However, this process creates tiny bubbles of vapour that can form a film over a hot surface and serve as an insulator, spoiling the cooling process.
In 2003 Ari Glezer and his colleagues at the Georgia Institute of Technology demonstrated one possible way to prevent this film from forming. They used jets of water to detach the bubbles, an approach that involved complex and bulky circulation systems.
Bubble trouble
Now Glezer's team has hit on a more efficient way to dislodge bubbles before they can coalesce into a film, using sound waves instead.
In experiments, the researchers placed an acoustic driver – essentially a speaker – sitting opposite from the heated surface, with cooling fluid in-between. They found that projecting just a small amount of sound energy, at frequencies near 1 kilohertz, across the fluid was enough to do dislodge the gathering bubbles. This increased the amount of heat that could be dissipated by as much as 147%.
The best results were achieved when the distance between the acoustic driver and the heated surface was just a few millimetres, which is good news for applications in which space is a premium. "The underwater jets solution is effective, but this way is more compact, requires less power, and is, well, more elegant," Glezer says.
Space applicationsGlezer predicts that sound-enhanced liquid cooling could find use in areas outside computing, perhaps keeping hybrid vehicles' high-powered components cool, for example.
Satish Kandlikar an expert on cooling technology at the Rochester Institute of Technology in New York, US, agrees. "This is a very interesting development," "It holds promise for applications such as chip cooling and micro-scale heat exchangers."
Kandlikar says the approach could also be suitable for keeping components cool in aircraft and space vehicles.
Source: New Scientist Tech
One of the best ways to remove heat quickly in high-power applications is to allow a liquid coolant to boil, so that the resulting vapour whisks away excess energy. However, this process creates tiny bubbles of vapour that can form a film over a hot surface and serve as an insulator, spoiling the cooling process.
In 2003 Ari Glezer and his colleagues at the Georgia Institute of Technology demonstrated one possible way to prevent this film from forming. They used jets of water to detach the bubbles, an approach that involved complex and bulky circulation systems.
Bubble trouble
Now Glezer's team has hit on a more efficient way to dislodge bubbles before they can coalesce into a film, using sound waves instead.
In experiments, the researchers placed an acoustic driver – essentially a speaker – sitting opposite from the heated surface, with cooling fluid in-between. They found that projecting just a small amount of sound energy, at frequencies near 1 kilohertz, across the fluid was enough to do dislodge the gathering bubbles. This increased the amount of heat that could be dissipated by as much as 147%.
The best results were achieved when the distance between the acoustic driver and the heated surface was just a few millimetres, which is good news for applications in which space is a premium. "The underwater jets solution is effective, but this way is more compact, requires less power, and is, well, more elegant," Glezer says.
Space applicationsGlezer predicts that sound-enhanced liquid cooling could find use in areas outside computing, perhaps keeping hybrid vehicles' high-powered components cool, for example.
Satish Kandlikar an expert on cooling technology at the Rochester Institute of Technology in New York, US, agrees. "This is a very interesting development," "It holds promise for applications such as chip cooling and micro-scale heat exchangers."
Kandlikar says the approach could also be suitable for keeping components cool in aircraft and space vehicles.
Source: New Scientist Tech
User comments
