Boiling in microchannels: integrated design of closed-loop cooling system for devices operating at high heat

The project aims to advance the use of microchannels based cooling technology by solving major outstanding issues. Flow instabilities and maldistribution are identified as a major hurdle towards effective implementation of this technology to a variety of applications.

The objectives of this project are to:

  1. Develop world leading fully integrated and instrumented microchannels for more fully characterising advanced cooling systems based on boiling in micro-channels.
  2. Perform advanced and detailed experiments generating new data on pressure fluctuations, local temperature, vapour dynamics and liquid film thickness during boiling in silicon and metal parallel micro-channels that will help elucidate fundamental mechanisms and validate the models.
  3. Validate the models and apply them in the development of rational methods of integrated design for systems for the stable, near-isothermal cooling of components operating at high heat fluxes.

Small-scale devices such as electronic chips, power rectifiers, radar arrays and chemical microreactors require cooling of areas of a few cm2 at heat fluxes now approaching several MW/m2, necessitating a progression from air to liquid and now potentially to evaporative cooling. In a DTI report on developments and trends in thermal management technologies, heat fluxes for power electronics and laser semi-conductors of above and beyond 1 MW/m2 were identified while in devices operating in the region of 100 W there can be local hot spots requiring removal of power densities of the order of 10 MW/m2. The performance and long-term reliability of many applications requires near-uniform, constant temperature, despite heat production that is spatially non-uniform and varies with time. Applications have specific constraints that influence the choice and working pressure of the coolant, e.g. electronic chips have to operate below a maximum temperature of 80oC, aerospace applications have to survive extremes of ambient temperature. Liquid-only cooling involves an increase in temperature of the coolant (and therefore a temperature gradient in the chip) from inlet to outlet.

Principal Investigator: 

Research Institutes: 

  • Multiscale Thermofluids

Research Themes: 

  • Multiphase flows, interfaces and phase change from nano- to macro-scales