Session: ASME Undergraduate Student Design Expo

Paper Number: 172704

Effect of Mixing Time on the Viscosity and Thermal Conductivity of Ionic Liquids-Based Nanofluids 

Conventional methods of energy generation have been found to have a detrimental impact on the environment. As a result, researchers are actively investigating alternative, clean, and renewable energy sources. Among these options, solar power has emerged as a highly efficient and sustainable energy source. One of the methods for employing solar power is the utilization of a concentrated solar power system (CSP) where heat energy is stored in heat transfer fluids (HTFs) from mirrors or lenses that are positioned to concentrate sunlight to a small area. Traditional HTFs used in the past to produce steam for energy production include Therminol VP-1 (eutectic mixture of biphenyl and diphenyl oxide), thermal oil, and molten salt. The problems associated with traditional HTFs are high melting points and low decomposition temperatures which increase operation costs, reduce system efficiency, and diminish energy storage potential. Thus, one of the primary motivators in studying ionic liquids (ILs) is to improve the properties and overall efficiency of HTFs. Advanced materials or engineered materials is one of the research areas for Vision 2030 South Carolina Science and Technology plan. Ionic liquids are a class of organic salts with low melting points, low volatility, low flammability, and high thermal conductivity, making them ideal candidates for HTFs. Additionally, ionic liquids have been found to possess negligible vapor pressure and high thermal stability that simplify the heat transfer process. Ionic liquids (ILs) based nanofluids are a new class of HTFs created by dispersing metal/metal oxide nanoparticles into base ILs subsequently increasing thermal conductivity and thermal performance.

The principal objective of the project is to investigate the effect of mixing time on the viscosity and thermal conductivity of ionic liquid-based nanofluids. The ILs based nanofluids prepared by dispersing a small weight percentage (0.5 wt%, 1 wt%, and 2.5 wt%) of nanoparticles on the base ILs and mixing them by using a vortex mixture (Mini Vortexture from Fisher Scientific) for different mixing times (15 min, 30 min, 45 min, 60 min, 75 min, 90 min, 105 min, and 120 min). From the initial screening of base ILs, the best candidate will be 1-butyl-3-methylimidazolium bis{(trifluoromethyl) sulfonyl}imide, ([C₄mim][NTf2]) ILs, because it has lower viscosity compared to the other three ILs that we have studied. lower viscosity will reduce the pumping power of the HTFs.  The results demonstrate a saturating exponential relationship between mixing time and viscosity. These findings contribute to the understanding of IL-based nanofluids for their application in heat transfer and retention.

Presenting Author: Jacob Phillips University of South Carolina Aiken

Presenting Author Biography: The presenting author is a senior undergraduate student in the mechanical engineering program at the University of South Carolina Aiken.

Authors:

Jacob Phillips University of South Carolina Aiken
Othello Cooper University of South Carolina Aiken
Titan Paul University of South Carolina Aiken