Investigating Aerodynamic Performance of Coaxial Dual Rotor Wind Turbine

Abstract

Wind turbine technology has advanced significantly as a result of the growing need for renewable energy to fight climate change and lessen reliance on fossil fuels. Dual-rotor wind turbines are one of these developments that shows promise for increasing energy extraction efficiency by absorbing wake energy that remains from the upwind rotor. The impact of rotor spacing, tip-speed ratio, rotating direction, and pitch angle on turbine efficiency are the main topics of this study, which examines the aerodynamic performance of coaxial dual-rotor wind turbines.

The study computes the effect of axial induction while neglecting tangential induction. It also highlights the distinct advantages of both co-rotating (CO-RWT) and counter-rotating (CR-RWT) systems, examining the aerodynamic differences between them. Actuator Disc Model (ADM) simulations, Blade Element Momentum (BEM) theories, and analytical techniques are used to determine velocity deficits and assess rotor interactions. The results show that CR-RWT setups provide better power. The findings demonstrate that CR-RWT configurations achieve high power coefficients due to improved wake recovery and reduced turbulence, while CO-RWT designs prioritize increased torque and power density.

The analysis reveals that parameters such as rotor spacing and TSR significantly influence the aerodynamic interactions between both the rotors. Optimal spacing minimizes wake interference, while precise control of TSR and pitch angles improves overall turbine performance. By systematically investigating these factors, this work identifies the conditions under which dual-rotor wind turbines can maximize energy output and efficiency. The study provides valuable insights into optimal design parameters for dual-rotor configuration, contributing to the development of cost-effective, high-efficiency wind turbines for future energy needs.