Investigation of the effect of turbulator and nano fluid usage on heat transfer in spiral pipe flow

In this thesis study; Thermo-flow behaviors of 6 different heat tubes, including straight, spiral and turbulator (straight, 10, 50 and 100 rpm) spiral, were numerically examined. The effect of fluids on heat transfer was investigated by using water and four different nanofluids (Water Al2O3, Water-TiO2, Water-Fe2O3, Water-CuO) as the working fluid. The effect of placing a turbulator in the spiral pipe and increasing the turbulator speed on heat transfer was investigated. The percentage density of nanofluids is 3%. The drawing of straight, spiral and turbulator spiral pipes was made with the SolidWorks 2023 program and transferred to the ANSYS 20 R2 environment. The length of straight, spiral and turbulator spiral pipes is 3 777 m and their diameter is 17 mm. Computational flow dynamic modeling of straight, spiral and turbulent spiral pipes was carried out with ANSYS 20 R2 program. Turbulent kinetic energy - dissipation (k-ε) model in improved wall functions was used for the numerical study. The discrete finite volume method was used to solve the valid equations. In the study, flow and heat transfer analyzes were performed by taking into account heat transfer conditions in turbulent and laminar flow. Reynolds number, different nanofluids, flow arrangements, speeds of turbulators, etc. The influence of important design parameters such as was of main interest. The results were carried out in different Reynolds number ranges for water (3000 - 40000) and for nanofluids (2000 - 40 000). The study was carried out at a constant wall temperature of 35 ℃ on all pipe types. Velocity, pressure and temperature contours of water and nanofluids were created in 6 different pipes. Velocity, pressure and temperature values of water and nanofluids in 6 different pipes were compared. Nusselt number (Nu), heat transfer coefficient (h), friction factor (f), outlet temperature (To) values of water and nanofluids in 6 different pipes were found and compared for these 6 different pipes. It was found that with increasing Reynolds number, Nusselt numbers and heat transfer coefficients increased for all fluids and all pipe types, while friction factor and outlet temperature values decreased. It was found that the spiral pipe provided more heat transfer and pressure drop than other pipes for water and all nanofluids. It was found that increasing the turbulator speeds did not contribute to heat transfer. It was found that TiO2 provided the highest heat transfer among the nanofluids, while CuO nanofluid provided the lowest heat transfer. It was found that water provides better heat transfer than nanofluids.