The main research direction and application of nanofluids
The high thermal conductivity of nanofluids enhances the heat transfer performance of the base fluid and provides a new solution for improving energy efficiency and reducing energy consumption. Many early literatures have confirmed the effective role of nanofluids in coolants and engine oils, such as aerospace engine heat exchange systems, automotive cooling systems, solar distillation systems, and micropipeline radiators.
The research mainly focuses on strengthening gas-liquid mass transfer. Compared with general gas-liquid mass transfer, nanofluids have large specific surface area and surface activity, which can greatly increase the contact area of gas and liquid and increase the absorption rate. Mainly used in environmental protection and natural gas storage.
Less friction and wear
The addition of nanoparticles to the nanofluid formed in the lubricating oil improves the tribological properties of the lubricating oil. The nanoparticles act as tiny rolling bearings in the vicinity of the contact area, thereby reducing the contact area and reducing the friction; the nanoparticles form a boundary adsorption film that separates the contact surfaces to reduce wear; the nanoparticles and nanofluids can suppress scratches And damage caused by scratches. Thereby increasing the efficiency of the machine and extending the service life of the machine components. Further research directions are: the controllable microstructure of nanofluids; the long-term stability of nanofluids, the stability under practical application and the stability after numerous thermal cycles; the theoretical system of nanofluids requires further experimental research.
Effect on contact fatigue life
Rolling contact fatigue (RCF) failure is a key factor leading to failure of frictional mechanical components, including rolling bearings, gears, cam rotors, etc., and RCF occurs when the alternating stress exceeds the minimum stress required for plastic deformation of the rolling elements. The RCF generates microcracks at the discontinuity of the subsurface structure and spreads to the surface to form surface flaking or pitting. The life of the RCF depends on the type of lubricating base oil and the use of the additive. Nanofluids can significantly improve the fatigue life of contact lubrication at a suitable additive level.
Reprinted from the network