NUMERICAL SIMULATION OF VERTICAL-AXIS WIND TURBINES ROTORS AERODYNAMICS BASED ON UNSTEADY NAVIER-STOKES EQUATIONS
DOI:
https://doi.org/10.32782/mathematical-modelling/2024-7-2-19Keywords:
vertical-axis wind turbine, Darrieus and Savonius rotors, Navier-Stokes equation, turbulence, dynamics and aerodynamicsAbstract
On the basis of unsteady Reynolds-averaged Navier-Stokes equations of incompressible fluid and the equation of rotation of a solid body relative to a fixed axis, a mathematical model is built to study the interaction of aerodynamics and dynamics of rotors of vertical-axis wind turbines. The software and methodological part of software for numerical simulation and determination of the main parameters of unsteady flow of rotors of vertical-axis wind turbines was developed. The unsteady flow of rotors of vertical-axis wind turbines was studied on the basis of the Navier-Stokes equations. The flow field around the Darrieus rotor is analyzed. The stages of vortex generations, development, and dissipation at different blade positions on the trajectory are distinguished. It is shown that viscous and dynamic effects play an important role in the operation of the Darrieus rotor, with the maximum torque generated on the windward part of the blade trajectory. The influence of the Reynolds number, tip-speed-ratio and solidity coefficients on the power characteristics of the Darrieus rotor is established. It is shown that an increase in the Reynolds number leads to an increase in the power characteristics. With a decrease in the Darrieus rotor solidity coefficient, the power characteristic becomes less sensitive to changes in the tip-speed-ratio. An increase in the tip-speed-ratio coefficient leads to suppression of the process of forming a dynamic flow separation from the blades of the Darrieus rotor. The coupled problem of dynamics and aerodynamics of a three-blade Savonius rotor is solved. The main stages of the vortex structure formation during the rotation of a twoand three-blade rotor are identified. In the studied range of defining parameters, the value of energy characteristics of the two-blade Savonius rotor is higher than that of the three-blade rotor. The results obtained are in satisfactory agreement with the known experimental data.
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