Scanning Electron Microscope Studies on Aggregation Characteristics of Alumina Nanofluids.

摘要

This research study establishes the relationship between sonication parameters and overall particle volume fraction in the base fluid, to the volume fraction of nanoparticles in the aggregate cluster and overall thermal conductivity enhancement of the nanofluid. The test matrix includes two power levels, with five overall particle volume fractions at each power level, and five sonication times for each overall particle volume fraction. The research concludes that sonication time has negligible effect on cluster size and number of particles per aggregate cluster at a constant overall particle volume fraction and vice versa. The research also concludes that nanofluid with higher thermal conductivity can be obtained when cluster size is limited to 200 nm. It is recommended that future research should emphasize on particle modification, such as encapsulation, to optimize and achieve an aggregate cluster size limit of 200 nm.