ABSTRACT
One of the most important scientic challenges in industrial centers is coolants, which involve many different products. Technological developments such as high-speed operational microelectronic systems and high-power motors, leading to increased thermal load, recall the necessity to develop coolants. In order to increase heat transfer, common methods may envisage with increased area for more heat transfer. This results in abnormal increase in size of heat management systems. So it seems that some new coolant is necessary, which improves the total performance of
heat transfer systems. The term nanouid is introduced by researchers as the suspension of nanosized particles (>100 nm) including metals, metallic oxide, and nanostructure in heat transfer base uids such as water and ethylene glycol. The main property of nanouids is enhanced thermal conductive and convective heat transfer compared to the base uid. Numerous efforts have been performed on nanouids with potential applications in industries such as microelectronic, defense, nuclear, aerospace, and industry. Before the advent of nanouid debate, convective and conductive heat transfers of uids were enhanced by adding
Introduction ............................................................................................................................................................................... 724 Higher Thermal Conductivity .............................................................................................................................................. 725 Stability ................................................................................................................................................................................ 725 Nonblocking Microchannels ................................................................................................................................................ 725 Decrease Erosion .................................................................................................................................................................. 725 Decreased Pump Power ........................................................................................................................................................ 725
Thermal Conductivity ............................................................................................................................................................... 726 Experimental Studies on Thermal Conductivity .................................................................................................................. 726
Effect of Nanoparticle Concentration .............................................................................................................................. 726 Effect of Nanoparticle Type ............................................................................................................................................ 727 Effect of Nanoparticle Size ............................................................................................................................................. 728 Effect of Nanoparticle Shape........................................................................................................................................... 728 Effect of Base Fluid Type ................................................................................................................................................ 728 Effect of Temperature ...................................................................................................................................................... 729 Effect of pH ..................................................................................................................................................................... 729 Effect of Surfactants ........................................................................................................................................................ 729 Effect of Ultrasonication ................................................................................................................................................. 730 Effect of Solid-Liquid Interface ...................................................................................................................................... 731 Effects of Brownian Motions, Thermophoresis, and Diffusiophoresis ........................................................................... 732
Theoretical Studies on Thermal Conductivity ..................................................................................................................... 738 Static Models ................................................................................................................................................................... 738 Dynamic Models ............................................................................................................................................................. 742
Viscosity .................................................................................................................................................................................... 747 Experimental Studies on Viscosity ....................................................................................................................................... 747 Theoretical Studies on Viscosity .......................................................................................................................................... 751
Specic Heat Capacity .............................................................................................................................................................. 754 Density ...................................................................................................................................................................................... 754 Thermal Expansion Coefcient ................................................................................................................................................ 758 Surface Tension ......................................................................................................................................................................... 758 Mass Diffusion Coefcients ...................................................................................................................................................... 759 References ..................................................................................................................................................................................761
