"We know the wicking part of the system is working well, so we now need to make sure the rest of the system works," North said.
The new type of cooling system can be used to prevent overheating of devices called insulated gate bipolar transistors, high-power switching transistors used in hybrid and electric vehicles. The chips are required to drive electric motors, switching large amounts of power from the battery pack to electrical coils needed to accelerate a vehicle from zero to 60 mph in 10 seconds or less.
Potential military applications include advanced systems such as radar, lasers and electronics in aircraft and vehicles. The chips used in the automotive and military applications generate 300 watts per square centimeter or more.
Researchers are studying the cooling system using a novel test facility developed by Weibel that mimics conditions inside a real heat pipe.
"The wick needs to be a good transporter of liquid but also a very good conductor of heat," Weibel said. "So the research focuses largely on determining how the thickness of the wick and size of copper particles affect the conduction of heat."
Computational models for the project were created by Garimella in collaboration with Jayathi Y. Murthy, a Purdue professor of mechanical engineering, and doctoral student Ram Ranjan. The carbon nanotubes were produced and studied at the university's Birck Nanotechnology Center in work led by mechanical engineering professor Timothy Fisher.
"We have validated the models against experiments, and we are conducting further experiments to more fully explore the results of simulations," Garimella said.
Inside the cooling system, water circulates as it is heated, boils and turns into a vapor in a component called the evaporator.
|Contact: Emil Venere|