Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tiny bubbles are key to liquid-cooled system for future computers

14.04.2003


Issam Mudawar, a professor of mechanical engineering at Purdue University, demonstrates the liquid-cooling system he has developed for future computers. Within about three years, microprocessor chips are expected to generate four times the amount of heat as current chips, requiring innovative cooling systems to keep the chips from being damaged by heat. (Purdue News Service Photo/David Umberger)


Purdue University researchers have made a discovery that may lead to the development of an innovative liquid-cooling system for future computer chips, which are expected to generate four times more heat than today’s chips.

Researchers had thought that bubbles might block the circulation of liquid forced to flow through "microchannels" only three times the width of a human hair. Engineers also thought that small electric pumps might be needed to push liquid through the narrow channels, increasing the cost and complexity while decreasing the reliability of new cooling systems for computers.

Purdue researchers, however, have solved both of these potential engineering hurdles, developing a "pumpless" liquid-cooling system that removes nearly six times more heat than existing miniature pumpless liquid-cooling systems, said Issam Mudawar, a professor of mechanical engineering.



Liquid forced through microchannels forms smaller bubbles than expected, Mudawar said he was surprised to learn. Moreover, decreasing the diameter of the microchannels increased the cooling efficiency of the system by causing the liquid to form even smaller bubbles, which is contrary to the expected result.

Because the bubbles are much smaller than the diameter of the microchannels, they flow easily through the channels. The Purdue-developed system does not require a pump because the liquid circulates in a self-sustaining flow in a closed loop that carries heat away from a computer chip.

Findings about the new cooling system are detailed in a research paper appearing in the March issue of IEEE Transactions on Components and Packaging Technologies, published by the Institute of Electrical and Electronics Engineers. The paper was written by Mudawar and graduate student Swaraj Mukherjee.

Innovative cooling systems will be needed in about three years for personal computers expected to contain microprocessor chips that will generate four times more heat than chips in current computers. Whereas current high-performance chips generate about 75 watts per square centimeter, chips in the near future will generate more than 300 watts per square centimeter, Mudawar said.

"Any time you squeeze more circuitry into the same space, you are producing more heat per unit area and per unit volume," he said.

Today’s computers use fans and heat sinks containing fins to help cool circuitry. But this technology will not be efficient enough to remove the increasing heat generated by future chips, Mudawar said.

His research team created a liquid-cooling system that uses a closed loop of two vertical, parallel tubes containing a dielectric liquid – or a liquid that does not conduct electricity. The liquid flows through microchannels in a metal plate that is touching the chip. As liquid flows through the channels, it is heated by the chip and begins to boil, producing bubbles of vapor. Because the buoyant vapor bubbles are lighter than the liquid, they rise to the top of the tube, where they are cooled by a fan and condensed back into a liquid. The cool liquid then flows into the parallel tube and descends, creating a self-sustaining flow that eventually re-enters the microchannel plate and starts all over again.

"We were surprised to see that the dielectric liquid forms really miniature bubbles, so they slip through really fast," Mudawar said. "The bubbles don’t block the flow, as you would expect."

The researchers found that the system was 5.7 times better at removing heat than existing miniature pumpless liquid-cooling systems.

"This is only a starting point, and much better performance might be possible," Mudawar said.

Future research will focus on testing various designs to see which configurations work best.

"Now that we have a system that we know will work, we are going to test different geometries that will be beneficial to industry," said Mudawar, director of the Purdue University International Electronic Cooling Alliance. The alliance brings together researchers from industry, government agencies and Purdue to design cooling systems for applications ranging from personal computers to spacecraft.

The research was funded by the U.S. Department of Energy’s Office of Science.

Writer: Emil Venere, (765) 494-4709, venere@purdue.edu

Source: Issam Mudawar, (765) 494-5705, mudawar@ecn.purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Emil Venere | Purdue News
Further information:
http://news.uns.purdue.edu/html4ever/030411.Mudawar.cooling.html
http://me.www.ecn.purdue.edu/ME/Fac_Staff/mudawar.whtml
http://www.ecn.purdue.edu/PUIECA/main.html

More articles from Process Engineering:

nachricht Decontaminating pesticide-polluted water using engineered nanomaterial and sunlight
16.01.2020 | Institut national de la recherche scientifique - INRS

nachricht TUM Agenda 2030: Combining forces for additive manufacturing
09.10.2019 | Technische Universität München

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Harnessing the rain for hydrovoltaics

Drops of water falling on or sliding over surfaces may leave behind traces of electrical charge, causing the drops to charge themselves. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz have now begun a detailed investigation into this phenomenon that accompanies us in every-day life. They developed a method to quantify the charge generation and additionally created a theoretical model to aid understanding. According to the scientists, the observed effect could be a source of generated power and an important building block for understanding frictional electricity.

Water drops sliding over non-conducting surfaces can be found everywhere in our lives: From the dripping of a coffee machine, to a rinse in the shower, to an...

Im Focus: A sensational discovery: Traces of rainforests in West Antarctica

90 million-year-old forest soil provides unexpected evidence for exceptionally warm climate near the South Pole in the Cretaceous

An international team of researchers led by geoscientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now...

Im Focus: Blocking the Iron Transport Could Stop Tuberculosis

The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply. When the iron transport into the bacteria is inhibited, the pathogen can no longer grow. This opens novel ways to develop targeted tuberculosis drugs.

One of the most devastating pathogens that lives inside human cells is Mycobacterium tuberculosis, the bacillus that causes tuberculosis. According to the...

Im Focus: Physicist from Hannover Develops New Photon Source for Tap-proof Communication

An international team with the participation of Prof. Dr. Michael Kues from the Cluster of Excellence PhoenixD at Leibniz University Hannover has developed a new method for generating quantum-entangled photons in a spectral range of light that was previously inaccessible. The discovery can make the encryption of satellite-based communications much more secure in the future.

A 15-member research team from the UK, Germany and Japan has developed a new method for generating and detecting quantum-entangled photons at a wavelength of...

Im Focus: Junior scientists at the University of Rostock invent a funnel for light

Together with their colleagues from the University of Würzburg, physicists from the group of Professor Alexander Szameit at the University of Rostock have devised a “funnel” for photons. Their discovery was recently published in the renowned journal Science and holds great promise for novel ultra-sensitive detectors as well as innovative applications in telecommunications and information processing.

The quantum-optical properties of light and its interaction with matter has fascinated the Rostock professor Alexander Szameit since College.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

13th AKL – International Laser Technology Congress: May 4–6, 2022 in Aachen – Laser Technology Live already this year!

02.04.2020 | Event News

“4th Hybrid Materials and Structures 2020” takes place over the internet

26.03.2020 | Event News

Most significant international Learning Analytics conference will take place – fully online

23.03.2020 | Event News

 
Latest News

Capturing 3D microstructures in real time

03.04.2020 | Materials Sciences

First SARS-CoV-2 genomes in Austria openly available

03.04.2020 | Life Sciences

Do urban fish exhibit impaired sleep? Light pollution suppresses melatonin production in European perch

03.04.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>