A detailed investigation and understanding of the stability mechanisms and applications of nanofluids

Recently, nanotechnology has played a major part in multifields of heat transfer processes and developed a remarkable progress in the energy applications. One of the most plausible applications of nanotechnology is to produce nanoparticles of high thermal conductivity and mixing with the base fluids that transfer energy forming what is called nanofluids. Adding of nanoparticles to the base fluid shows a remarkable enhancement of the thermal properties of the base properties. Nanotechnology has greatly improved the science of heat transfer by improving the properties of the energy-transmitting fluids. A high heat transfer could be obtained through the creation of innovative fluid (nanofluids). This also reduces the size of heat transfer equipment and saves energy. Nowadays, the energy demand worldwide is steadily increasing due to the fast progress in technology in all fields of life. On the other hand, the fossil fuel had been taken to decrease, and the alternatives of energy sources are still under research to raise their efficiency. Besides, the fossil fuel has led to the environment degradation and global warming. Revolution of nanotechnology and its unique features compared with the large scale of its originality has been given a major focus. This dramatic growth stemmed from the multiapplications in various fields of life: medicine, agriculture, engineering, and industry. Nanotechnology, as a scientific major, studies the properties of nanoscale materials. Nanotechnology-based techniques could be produced by small particles in the size of nano of some solid materials such as alumina and titanium oxide that have relatively high thermal conductivity. The word “nano” is described as ۱ billionth of meter or ۱۰−۹ m. These nanosized particles are mixed in the base fluid of heat transfer forming a colloidal solution in the stable case, while its addition to the base fluids of low thermal conductivity probably increases the heat transfer characteristics of the base fluids. This creative fluid is known as nanofluid, which has a new heat transfer characteristic as one of the recent outcomes of nanotechnology. This makes, of course, saving energy exactly similar to reducing the volume of heat transfer equipment. Nanofluids have been receiving great attention in recent years due to their potential usage, not only as an enhanced thermophysical heat transfer fluid but also because of their great importance in applications such as drug delivery and oil recovery. Nevertheless, there are some challenges that need to be solved before nanofluids can become commercially acceptable. The main challenges of nanofluids are their stability and operational performance. Nanofluids stability is significantly important in order to maintain their thermophysical properties after fabrication for a long period of time. Therefore, enhancing nanofluids stability and understanding nanofluid behaviour are part of the chain needed to commercialise such type of advanced fluids.

کلیدواژه ها:

Nanofluids ، Fabrication ، Stability ، Thermophysical Properties