Numerical investigation of nanofluid flow and heat transfer by single phase and two phase methods

High cost of obtaining nanofluids and forming a healthy experimental setup, which is correctly isolated from disturbing effects, has led to the need for numerical modeling to investigate the effects of nanofluids on heat transfer. Therefore, it is important that the numerical studies are as reliable as the experimental studies. This will lead to the results being more accurate. In this study, the reference experimental data were selected and experimental study was modeled close to the actual systems in the ANSYS Fluent computational fluid mechanics package program, together with the application parameters and boundary conditions. Experimental study parameters and their effects were considered as reference, analyzed numerically with single phase and two phase models. According to the outcome, the analysis made with the Single Phase Brownian model, it was found that it gave the most accurate avarage heat transfer coefficient value to the experimental data. The two phase Euler-mixture model showed the most inaccurate results from the experimental data. The reason behind the two phase Euler-Mixture model resulting in a higher error rate, according to experimental data, was investigated numerically. As a result of the analyzes, it was concluded that the equation, which was giving the thermal conductivity in Euler-Mixture model, should have been changed in order to apply the two-phase Euler-Mixture model to the nanofluids more efficiently. The equation, which calculates the thermal conductivity of two-phase Euler-Mixture Model, is replaced by the Maxwell thermal conductivity equation. The Euler-Mixture model, which was reinterpreted, was observed to be the model that gave the most accurate results according to the experimental data. In addition, besides the equations determining thermophysical properties and models, the effect of parameters such as nanoparticle type, volume concentration and Peclet number on heat transfer was investigated numerically.