Reliability of numerical wind tunnels for VAWT simulation

The Science of Making Torque from Wind

Castelli, M. Raciti^1 ; Masi, M.^1 ; Battisti, L.^2 ; Benini, E.^2 ; Brighenti, A.^2 ; Dossena, V.^3 ; Persico, G.^3

Department of Management and Engineering, University of Padova, Stradella S. Nicola 3, Vicenza

36100, Italy^1

Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, Trento

38123, Italy^2

Energy Department, Politecnico di Milano, via Lambruschini 4, Milano

20158, Italy^3

关键词: Experimental survey;    Integral quantity;    Jet wind tunnels;    Numerical predictions;    Numerical wind tunnels;    Unsteady reynolds averaged navier-stokes equations;    Unstructured grid;    Vertical axis wind turbines;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/753/8/082025/pdf
DOI  :  10.1088/1742-6596/753/8/082025

来源: IOP

【 摘 要 】

Computational Fluid Dynamics (CFD) based on the Unsteady Reynolds Averaged Navier Stokes (URANS) equations have long been widely used to study vertical axis wind turbines (VAWTs). Following a comprehensive experimental survey on the wakes downwind of a troposkien-shaped rotor, a campaign of bi-dimensional simulations is presented here, with the aim of assessing its reliability in reproducing the main features of the flow, also identifying areas needing additional research. Starting from both a well consolidated turbulence model (k-ω SST) and an unstructured grid typology, the main simulation settings are here manipulated in a convenient form to tackle rotating grids reproducing a VAWT operating in an open jet wind tunnel. The dependence of the numerical predictions from the selected grid spacing is investigated, thus establishing the less refined grid size that is still capable of capturing some relevant flow features such as integral quantities (rotor torque) and local ones (wake velocities).