Optimization of design parameters for nanofluids flowing inside helical coils

In this study water/Al2O3nanofluid is used in helical tubes. Copper helical tubes are in constant wall temperature and the fluid flow is laminar. Thermophysical properties of Nanofluids are assumed to depend on particles volume fraction and temperature. To analyze the heat transfer rate and pressure drop in helical coils, Nusselt number, friction factor and thermal–hydraulic parameter are used. Numerical simulation and Taguchi method are used to investigate the effect of fluid flow and geometrical parameters on JF factor. After simulations, Taguchi method is used for finding the optimum condition for the desired parameters. Proposed optimum conditions are simulated to insure the obtained results. Results indicate that Nanofluids improve the thermal–hydraulic performance of helical tubes. On the other hand using Nanofluids don't change the optimized shape factors but temperature dependent properties alter the optimum particle volume fraction.