JAM 1 1 1935 b T I ENHANCING THERMAL CONDUCTIVITY OF FLUIDS WITH NANOPARTICLES *

to be submitted to ASME International Mechanical Engineering Congress & Exposition, November 12-17, 1995, San Francisco, CA. Work supported by the U.S. Department of Energy, Basic Energy Sciences-Materials Sciences, under contract #W-31-109-ENG-38. DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED^T ENHANCING THERMAL CONDUCTIVITY OF FLUIDS WITH NANOPARTICLES Stephen U. S. Choi and Jeffrey A. Eastman 2 Energy Technology Division and Materials Science Division Argonne National Laboratory Argonne, Illinois ABSTRACT Low thermal conductivity is a primary limitation in the development of energy-efficient heat transfer fluids that are required in many industrial applications. In this paper we propose that an innovative new class of heat transfer fluids can be engineered by suspending metallic nanoparticles in conventional heat transfer fluids. The resulting "nanofluids" are expected to exhibit high thermal conductivities compared to those of currently used heat transfer fluids, and they represent the best hope for enhancement of heat transfer. The results of a theoretical study of the thermal conductivity of nanofluids with copper nanophase materials are presented, the potential benefits of the fluids are estimated, and it is shown that one of the benefits of nanofluids will be dramatic reductions in heat exchanger pumping power.Low thermal conductivity is a primary limitation in the development of energy-efficient heat transfer fluids that are required in many industrial applications. In this paper we propose that an innovative new class of heat transfer fluids can be engineered by suspending metallic nanoparticles in conventional heat transfer fluids. The resulting "nanofluids" are expected to exhibit high thermal conductivities compared to those of currently used heat transfer fluids, and they represent the best hope for enhancement of heat transfer. The results of a theoretical study of the thermal conductivity of nanofluids with copper nanophase materials are presented, the potential benefits of the fluids are estimated, and it is shown that one of the benefits of nanofluids will be dramatic reductions in heat exchanger pumping power. NOMENCLATURE d f h k L n Nu P Pr Re