Numerical investigation of flow characteristics of different type fittings using nanofluid

In this study, flow characteristics and pressure drops are investigated numerically by passing nanofluids through the fittings (L, T, 90 ° turning elbow, sudden contraction and sudden expansion) commonly used in installations. Aluminum, copper and titanium based nanoparticles were added homogeneously to water to obtain nanofluids. Five different concentrations of Al2O3 (%0.3, %0.5, %1, %2, %3), four different concentrations of Ti2O (%0.05, %0.1, %0.3, %0.5) and three different concentrations of CuO (%1, %2, %4) have been discussed. The Reynolds number was determined as Re = 500 and Re = 5000 to examine the structure of the flow through the fittings under both turbulent and laminar conditions. The results obtained by using water were confirmed with the literature results and nano-fluid calculations were started. In order to determine the most accurate numerical model; laminar model, k- ϵ RNG turbulence model, k- ϵ Standard turbulence model and k- ω Standard turbulence model were used. It was observed that as the concentration increased for all nanofluids, local losses increased due to the increase in viscosity. When the different fittings and different turbulence models are examined, it is seen that the most suitable model for Reynolds number, Re = 500 is laminar model for T, L and elbow connection part. The k- ϵ RNG model was found to be most suitable model in the sudden conctraction and sudden expansion connection pieces joints where sudden vortex ruptures occured as a result of the change of section. The most suitable model for the Reynolds number, Re=5000 for T, L and elbow fittings is k - ϵ Standard model; however, the k - ϵ RNG model has been shown to give the best results fort he sudden conctraction and sudden expansion fragments. The k - ω standard turbulence model was found to be unsuitable for any fittings.