Nao Fluids Case Study

CHAPTER-2

NANO FLUIDS

Nano fluids are a new kind of approach for heat transfer applications. Nano fluids are containing nanoparticles having size of 1–100 nm, which are uniformly and stably suspended in a base fluid. Generally metals or metal-oxides used as Nanoparticles and they greatly enhance the thermal conductivity of the Nano fluids. Nano fluids have been considered for so many industrial applications for advanced heat transfer fluids for two decades. However, due to complexity of the Nano fluid systems, there is no agreement has been achieved in heat transfer processes. Nano fluids have the following advantages: Nano fluids have broad surface area and more heat transfer rate occurs between particles and base fluids. High dispersal

The four unique features observed from the first test are listed below by Das and Choi [23]. Abnormal enhancement of thermal conductivity: The most important feature observed in Nano fluids was an abnormal raise in thermal conductivity. Stability: Nano fluids have been described to be stable over months by using a stabilizing agent. Small concentration and Newtonian behavior: Eminent enhancement of conductivity was achieved with small concentration of Nanoparticles that completely maintained the Newtonian behavior of the fluid. The raise in viscosity was nominal; hence, pressure drop was increased slightly. Particles size dependence: Unlike the situation with micro slurries, the enhancement of conductivity was found not only on particle concentration but also on particle size. In general, it is observed that, by decreasing of particle size leads to increase in enhancement.

The above potentials provided the thrust necessary to begin research in Nano fluids and these fluids will play an important role is extended to next generation of cooling systems. The result can be a highly conducting and stable Nano fluid with exciting newer applications in the