Nanofluids as Coolants


Nanofluids, consisting of nanometer-sized solid particles and fibers dispersed in fluids, have great potential for improving the heat transfer properties of liquids. Several characteristic behaviors of nanofluids have been identified, including the possibility of obtaining large increases in thermal conductivity compared with liquids without nano particles, strong temperature-dependent effects, and significant increases in critical heat flux. In Carbon nanotubes based nanofluids; CNTs are playing the role of the nanometric solid particles which enhances the properties of these fluids.
CNTs are highly inert and stable in nature, hence does not disperse in liquids. To disperse it in liquids, it is important to functionalize the surface of CNTs by some oxygen containing groups, which in turn makes these CNTs hydrophilic. In this nanoparticle suspension, thermal properties are greatly determined by the size of the suspended solid particles. These nanofluids have tremendous applications in future industries as coolant, refrigerating liquid and in battery industry.

Magnetic Nanofluids


Magnetic nanofluids are prominent materials in engineering as well as biomedical applications. In medical applications, for example, ferrofluid provides new cancer treatment techniques by employing iron based nanoparticles as delivery vehicles for drugs or radiation. Our group synthesizes magnetic nanofluids by decorating carbon based nanostructures with magnetic materials. The thermal conductivity of these nanofluids has been measured with magnetic field and without magnetic field.
With magnetic field the nanofluid shows more enhancements in thermal conductivity than that without magnetic field. This anomalous enhancement is due to the alignment of magnetic dipole in the direction of magnetic field. When magnetic dipoles will align in the direction of magnetic field, there will be thermal continuity between the particles, which increases the thermal conductivity.Ferrofluids are used for many applications such as dynamic mechanical seals, airborne seals for protection of optical devices and sensitive electronic instrumentation in military and surveillance aircraft, stimulant for enhancing chemical reactions and medical diagnostics and therapy.

Transformer Oil Based Insulating Nanofluids

Ever since Choi connotes the idea of nanofluids, there has been considerable interest in the thermal performance of these nanoparticle suspensions. Nanofluids are considered to be best alternative to liquid based cooling systems in electronic devices. Transformer oil (insulating oil) is a highly-refinedmineral oil, used in oil-filled transformers that is stable at high temperatures and has excellent electrical insulating properties. The oil helps cool the transformer. Because it also provides part of theelectrical insulationbetween internal live parts, transformer oil must remain stable at high temperatures for an extended period.


Nanofluids for Fuel cells and Computers

Heat transfer fluids with 0 D, 1 D, 2 D and 3 D nanomaterials with large enhancement in thermal conductivity and heat transfer coefficient with different base fluids. The low electrical conductivity of some of the nanofluids with insulating nanomaterials makes these potential applications in electronic circuits. These nanofliods are non-corrosive with high stability for long-term efficient operation.




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