Andrzej Gierczycki

Influence of Nonionic Surfactant Addition on Drag Reduction of Water Based Nanofluid in a Small Diameter Pipe

Abstract The goal of this research was to determine the impact of nonionic surfactants on drag reduction effect in water and metal oxide nanofluid. Two nonionic surfactants (Rokacet O7 and Rokanol K7) and copper(II) oxide water-based nanofluid were examined. Friction factors in a 4 mm diameter pipe for the Reynolds number between 8000 and 50000 were determined. Results showed that addition of nonionic surfactants caused the decrease of friction factor in water and nanofluid. The drag reduction effect was similar in both cases. Presence of nanoparticles in the system has no great influence on drag reduction effect.

Impact of heating method on the flocculation process using thermosensitive polymer.

The impact of suspension heating method on the flocculation process using thermosensitive polymer is reported in this paper. In experiments a model suspension of chalk in RO water (purified by Reverse Osmosis) was destabilized using a copolymer of N-isopropylacrylamide (NIPAM) and cationic diallyldimethyl ammonium chloride (DADMAC). The measurements were made using a laboratory setup consisting of a mixing tank with four baffles, Rushton turbine, laser particle sizer Analysette 22 by Fritsch and a system of pump and thermostating devices. Two different modes of heating were used. In the first case the temperature of the system was gently raised above the Lower Critical Solution Temperature (LCST) using an electrical heater placed inside the tank, while in the second case the system temperature was rapidly raised by an injection of hot water directly into the tank. It was proven that heating method as well as the polymer concentration was crucial to the shape and size of created flocs.

AGGREGATION AND BREAKAGE OF SOLID PARTICLES IN SUSPENSIONS AGITATED IN A VIBRATING MIXER: A NON-FRACTAL APPROACH

ABSTRACT Aggregation and breakage of solid particles or aggregates suspended in liquid can be found in numerous industrial processes. It is crucially important to predict the evolution of aggregates at any moment during the process. This aim can be achieved by modeling based on solid phase population balances. A lumped discrete population balance model has been selected for the verification of the experimental data. The experiments have been carried out in a laboratory-scale vibrating mixer equipped with a disc-type reciprocating impeller. A reasonably good agreement between the computational and experimental results of PSD data has been obtained. Dependencies between aggregation and breakage rate coefficients and the average energy dissipation rate in the mixer have been shown.

Application of Klein's equation for description of viscosity of nanofluid

Abstract Paper presents results of investigations on rheological properties of CuO-water and CuO-ethylene glycol nanoflmds. It was found that mentioned nanofluids exhibit non-Newtonian properties and their flow curves can be approximated by means of Hershel-Bulkleys rheological model. A mutual influence of share stress and temperature on viscosity of nanofluids can be described accurately by means of Kleins equation.

Experimental Investigation of Heat Transfer to Nanofluids

Experimental investigations of convective heat transfer in nanofluid based on the Cu (approx. 0.15% and 0.25% vol.) nanoparticles synthesized in polyol process were conducted at constant heat flux conditions. A 30% increase in average heat transfer coefficient was found against the results obtained for a pure host liquid (ethylene glycol). Even more significant increase was in the entrance region.Copyright