Effects of Nanoparticles and Polymer Additives in Turbulent Pipe Flow Available to Purchase

Spatial and temporal characteristics of turbulent pipe flows using nanofluids and dilute polymer solutions are examined by means of instantaneous differential pressure and velocity measurements. Spherical and elongated nanosilica particles (SiO₂) are mixed into water to make nanofluid and polyacrylamide (PAC) is dissolved into water to make PAC solution. The effects of nanofluid on the drag reduction and turbulent structure are determined and compared with the effects of polymer additives on the turbulent structures and drag reduction. Suppression of turbulence near pipe wall was observed with the introduction of both spherical and elongated nanoparticles. Although experimental results show that nanofluids are not candidates for drag reduction unlike polymer additives, they do not increase pressure drop. Hence addition of nanoparticles into heat transfer fluids could have the potential for heat transfer enhancement in pipe flow without paying the penalty of increasing pumping power.