A particle image velocimetry study of dual-rotor counter-rotating wind turbine near wake

Abstract

This experimental work studied the flow characteristics in the near wake region behind dual-rotor wind turbines using two-dimensional particle image velocimetry. Two auxiliary rotors of 50% and 80% scale of the main rotor were installed upwind and operated in counter-rotating condition, which are compared to the conventional single-rotor turbine. In all the three configurations, a constant Reynolds number 9:5 Â 10 4 was applied, and all the rotors operated at a fixed tip speed ratio of 3.46. The mean and phaseaveraged velocity fields were investigated together with the turbulence kinetic energy. It was found that the two auxiliary rotors do not result in a significantly different wake flow property. The configuration implementing the 50% auxiliary rotor sees a slightly better wake characteristics, in terms of weaker main rotor tip vortices and a counter-rotating swirling shear region at the mid-span behind the main rotor. The decay rates of the peak vorticity of the main rotor tip vortices and their circulation are found to follow an exponential manner.

Unsteady aerodynamic modelling for dual-rotor wind turbines with lifting surface method and free wake model

“…Investigation on DRWT has been carried recently to optimize its performance by several parameters and to reveal the mechanism. Experiments with PIV [1,2] and methods including blade element momentum method [3] vortex methods and CFD [4,5] are applied. BEM method faces the challenge of modelling the nonuniform inflow of rear rotor and rotor-rotor interaction, while vortex methods based on potential theory can consider the interaction of either wake and either rotor with less computational cost than CFD.…”

Assessment of a District Trigeneration Biomass Powered Double Organic Rankine Cycle as Primed Mover and Supported Cooling

“…The incorporation of renewable energy becomes more important, particularly as the economies of several nations is improving [3]. From several renewable energy sources available, biomass is considered to be the most viable option as it generates enough heat for stable functioning in comparison with the wind, solar, and hydro sources, or it is constraint by location like geothermal [4][5][6][7].…”