An efficient hydrodynamic method for cross-flow turbines performance evaluation and comparison with the experiment

Abstract

Renewable energies are getting ongoing growing interest and so are cross-flow turbines to harness water energy to produce electrical energy. Use of numerical methods to evaluate and predict this type of turbine performance can be of major help. This paper presents a Darrieus turbine numerical performance results. The present numerical method uses hydrodynamics theory applied to this turbine with three rotating blades, taking in consideration their relative angle of attack and hydrodynamic coefficients changes with the azimuthal angle. A comparison of these results with our experimental results is done for five water flow velocities (V = 0.43–0.73 m/s). The computer source code developed in this study allows determining this turbine torque, mechanical power and their coefficients.Good agreement between the numerical and experimental results is observed. For instance, for V = 0.73 m/s, the relative differences between the numerical and experimental maximal torque, mechanical power and their coefficients are respectively equal to 1.85%, 5.33%, 1.85% and 1.85%. The maximal torque and power relative differences vary respectively from 1.33% to 4.76% and from −3.95% to 10.40% for the other flow velocities. This new approach could be very useful because of its merit of providing a good performance evaluation of cross-flow turbines with much less computing time and much lower cost than computational fluid dynamics software methods.