Heat transfer in dielectric fluids

The removal of heat from power and micro electronic systems using total liquid cooling is becoming popular and necessary. Traditionally such systems have been air-cooled. This is noisy, due to methods of forced convection, and inefficient because the fluid has a low specific heat. Natural convection of the dielectric fluid transfers the heat from the electronic components to a heat exchanger. Solvay produce a range of PFPE based dielectric fluids: the physical properties, e.g. specific heat, coefficient of expansion, boiling point etc. are known, but the rate and manner in which heat transfers via the dielectric fluids requires detailed analysis. For a given power input, how hot does the dielectric fluid get? What is the flow field near protruding components? Can potentially damaging hot spots occur near stagnant flow regions? For enclosed systems, fluids are used which do not boil at the relevant temperatures, but it would be possible to use fluids with a lower boiling point, so multiphase flow would occur. Would boiling improve the heat transfer or make it worse? Possibly the additional turbulence might even out the temperature. The research is anticipated to be directly applied to the Iceotope designed total liquid cooling application.