Evaluation of Nanofluids as Potential Novel Coolant for Aircraft Applications: The case of Vaporization

J.A. Narvaez, A.R. Veydt, R.J. Wilkens
University of Dayton, US

Keywords: nanofluid, aircraft, vaporization, heat transfer coefficient

Summary:

Technological advances especially in miniaturization and microelectronics, have led to the development of smaller devices with increasing power density for the military aircraft industry. Therefore, demand for better coolants has intensified. The heat transfer capabilities of traditional coolants are insufficient to satisfy this demand. Nanofluids have been studied as potential novel coolants. Researchers have reported enhancements in thermal conductivity and heat transfer coefficient when nanofluids were used instead of their base fluids. There are some problems related to the use of nanofluids that have been addressed, such as high viscosity, clustering, stability of the suspension, and abrasion. However, there is a potential serious problem that has not been sufficiently addressed: vaporization may occur in microcooling applications of nanofluids. Vaporization is a major problem in aircraft applications. The objective of this research is to evaluate the effect of adding nanoparticles to a base fluid on heat transfer coefficient, particularly the problem of vaporization. Experimental results show no significant enhancement in heat transfer coefficient and high increase in wall temperature when nanofluids are used instead of liquids. Results raised doubts about the applicability of using nanofluids as alternative coolants for avionic applications.