The objectives of this project are to:
- Develop world leading fully integrated and instrumented microchannels for more fully characterising advanced cooling systems based on boiling in micro-channels.
- 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.
- 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.