Suhaib Umer Ilyas

A Review on the Viscous and Thermal Transport Properties of Nanofluids

In modern science and engineering nanofluids are playing a vital role in the application of heat transfer devices due to their effective properties. Addition of nanoparticles in the fluid can alter thermophysical properties of the nanofluid. Experimental and theoretical studies are essential to understand the change in fluid dynamics aspects of the fluid by the addition of nanoparticles. This paper presents a brief review on the viscous and thermal transport effects of nanofluids. The main emphasis is on the comparison of previous theoretical and experimental studies for thermophysical properties of nanofluids. These properties include density, viscosity, thermal conductivity and specific heat capacity of nanofluids.

Settling Characteristics of Alumina Nanoparticles in Ethanol-Water Mixtures

Nanofluids are considered as promising heat transfer fluids due to enhanced heat transfer ability as compared to the base fluid alone. Knowledge of settling characteristics of nanofluids has great importance towards stability of nanosuspensions. Sedimentation behavior of Alumina nanoparticles due to gravity has been investigated using different proportions of ethanol-water binary mixtures. Nanoparticles of 40 nm and 50 nm are used in this investigation at 23°C. Sediment height with respect to time is measured by visualization method in batch sedimentation. The effect of sonication on the sedimentation behavior is also studied using ultrasonic agitator. The effect of particle diameter, nanoparticle concentration and ethanol-water proportion on sedimentation behavior of nanofluids has been investigated and discussed.

Stability of Nanofluids

Nanofluids are the dilute suspensions of nanomaterials with distinctive and enhanced features. Nanofluids can be used in a variety of industrial applications because of improved thermophysical properties. Stability of nanofluids is the only quandary factor which decreases the efficiency of such smart fluids in engineering applications. The information and studies on interaction of nanomaterials with the liquid have significant importance toward their usage in industrial applications. Agglomeration among particles is a common issue due to interactive forces, which effects the dispersion, rheology, and overall performance of nanosuspensions. Characterization of nanofluids plays an important role to evaluate the stability of nanofluids. The effect of agglomeration on the stability of nanofluids can be reduced by introducing different mechanical and chemical techniques to prolong dispersion of suspended particles in liquids. Complete understanding on the stability of nanofluids can lead to the preparation of different combinations of stable nanofluids with enhanced properties for variety of applications.