Author: Nathaniel Wei, Ian Brownstein, J.L. Cardona, M.F. Howland, John DabiriPublication: J. Fluid Mech.Year Published: 2020 To design and optimize arrays of vertical-axis wind turbines (VAWTs) for maximal power density and minimal wake losses, a careful consideration of the inherently three-dimensional structure of the wakes of these turbines in real operating conditions is needed. Accordingly,…
Author: H.F. Lam, H.Y. PengPublication: EnergyYear Published: 2017 Increasing the efficiency of individual vertical-axis wind turbines (VAWTs) has been the subject of much research. However, wind farms that comprise individual VAWTs are not necessarily the most efficient configuration in accordance with VAWTs’ signature wake pattern. This study aims to identify efficient array configurations and thereby…
Author: aniel Araya, Anna. Craig, Matthias Kinzel, and John DabiriPublication: J. Renewable and Sustainable EnergyYear Published: 2014 We develop and characterize a low-order model of the mean flow through an array of vertical-axis wind turbines (VAWTs), consisting of a uniform flow and pairs of potential sources and sinks to represent each VAWT. The source and…
Author: Tanmoy Chatterjee, Yulia PeetPublication: Wind EnergyYear Published: 2018 Wind farms are known to modulate large scale structures in and around the wake regions of the turbines. The potential benefits of placing small hub height, small rotor turbines in between the large turbines in a wind farm to take advantage of such modulated large‐scale eddies…
Author: Vincent F-C. Rolin, Fernando Porté-AgelPublication: Renewable EnergyYear Published: 2018 In this experiment, a small scale vertical-axis wind-turbine (VAWT) is immersed in a boundary-layer in a wind tunnel and stereo particle image velocimetry is employed to quantify the 3D characteristics of the wake. The measurements show that the wake is strongest behind the sector of…
Author: Matthias Kinzel, Quinn Mulligan and John DabiriPublication: Journal of TurbulenceYear Published: 2012 We analyze the flow field within an array of 18 counter-rotating, vertical-axis wind turbines (VAWTs), with an emphasis on the fluxes of mean and turbulence kinetic energy. The turbine wakes and the recovery of the mean wind speed between the turbine rows…
Author: Shengbail Xie, Cristina Archer, Niranjan Ghaisas and Charles MeneveauPublication: Wiley Online LibraryYear Published: 2016 In this study, we address the benefits of a vertically staggered (VS) wind farm, in which vertical-axis and horizontal-axis wind turbines are collocated in a large wind farm. The case study consists of 20 small vertical-axis turbines added around each…
Author: Daniel ArayaPublication: California Institute of TechnologyYear Published: 2016 Within a wind farm, multiple turbine wakes can interact and have a substantial effect on the overall power production. This makes an understanding of the wake recovery process critically important to optimizing wind farm efficiency. Vertical-axis wind turbines (VAWTs) exhibit features that are amenable to dramatically…
Author: Horia Dumitrescu, Vladimir CardosPublication: ResearchGateYear Published: 2014 The fatigue analysis of a wind turbine component typically uses representative samples of cyclic loads to determine lifetime loads. In this paper, several techniques currently in use are compared to one another based on fatigue life analyses. The generalized Weibull fitting technique is used to remove the…
Author: Daniel Araya, John DabiriPublication: Springer-Verlag Berlin HeidelbergYear Published: 2015 We present experimental data to compare and contrast the wake characteristics of a turbine whose rotation is either driven by the oncoming flow or prescribed by a motor. Velocity measurements are collected using two-dimensional particle image velocimetry in the nearwake region of a lift-based, vertical-axis…