Influence of Computational Modelling Techniques on the Performance Predictability of the Hybrid Hydrokinetic Turbine Rotor

In recent times, the computational fluid dynamics (CFD) tool has become a virtual laboratory for the performance evaluation of systems. Computational modelling techniques can predict the performance of the hybrid hydrokinetic turbine (HKT) rotor effectively. Hence, a numerical investigation of a hybrid HKT rotor by adopting 2D and 3D CFD modelling techniques has been carried out. RNG k-ε turbulence model is considered for solving Unsteady Reynolds average Navier’s Stokes equations using ANSYS CFX solver. Based on numerical analysis, it is perceived that the power coefficient predicted by 2D and 3D models was found to have a minimum deviation at lower values of TSR. However, at higher values of TSR, the 2D model overpredicted the power coefficient compared to the 3D model. The numerical simulation results are compared with experimental data and it found that the 3D model is the best approach to validate the numerical results. Although, the computational time taken for 3D modelling was found to have eight times more than the time taken by the 2D modelling technique. However, the 3D CFD technique justifies the accuracy of the numerical solution. The justification of overprediction of the 2D model compared to the 3D model has also been examined by plotting different contour plots.