Nanofluids for Nuclear Applications

The use of nanofluids (colloidal binary systems of water and nanoparticles) has been shown to enhance the boiling critical heat flux (CHF), which can ultimately result in power density increases in boiling systems, such as nuclear reactors, high-power electronics, heat exchangers, etc. In the past year, Professor Buongiorno and Dr. Linwen Hu’s research program on nanofluids has focused on studying the detailed features of nanofluid boiling. The work is enabled by the deployment of a unique pool boiling facility equipped with infra-red thermography, which allows for acquisition of the two-dimensional time-dependent temperature distribution on the boiling surface. Traditional hard-to-measure parameters such as bubble frequency, departure diameter and nucleation site density are accurately obtained with this facility, and can reveal the subtle differences between nanofluid and water boiling behavior. Data interpretation is underway.

An experimental investigation of nanofluid convective heat transfer in the turbulent and laminar flow regimes was completed and revealed that, if the measured properties of the nanofluids are used in defining the governing dimensionless groups, the traditional correlations/models accurately reproduce the heat transfer and viscous pressure loss behavior of the nanofluids. This is a significant finding because controversial abnormalities in nanofluids heat transfer had been reported previously in the literature.

At the first scientific conference entirely dedicated to nanofluids (Nanofluids: Fundamentals and Applications , September 16-20, 2007, Copper Mountain, Colorado), it was decided to launch an international nanofluid property benchmark exercise (INPBE) to validate nanofluid property measurements (particularly of thermal conductivity) performed with various experimental methods, and to generate a reliable database of nanofluid properties. Twenty-four organizations from the US, UK, France, Switzerland, South Korea, India, China and Singapore participate in the exercise, which is coordinated by Prof. Buongiorno.