Wind turbine performance in shear flow and in the wake of another turbine through high fidelity numerical simulations with moving mesh technique

Abstract

We present numerical simulations of two horizontal axis wind turbines, one operating under the wake of the other, under an incoming sheared velocity profile. We use a moving mesh technique to represent the rotation of the turbine blades and solve the unsteady Reynolds averaged Navier-Stokes equations with a shear stress transport k ! turbulence model. Temporal evolution of the lift and drag coefficients of the front turbine show a phase shift in the periodic cycle due to the non-uniform incoming free stream velocity. Comparisons of the lift and drag coefficients for the back turbine with the unperturbed behaviour of the front demonstrate the complex non-linear interactions of the blades with the wake, with a significant decrease in overall performance and two peaks at specific points in the cycle associated with local angle of attack modification in the wake. The vorticity field in the near wake shows tilting of the vortex lines in the wake due to the shear and a faster diffusion of the tip vortical signature compared with the uniform free stream velocity case. Observations of the wake-wake interaction show good agreement with recent studies that use different methodologies.

Numerical Investigation of the Effect of Tower Dam and Rotor Misalignment on Performance and Loads of a Large Wind Turbine in the Atmospheric Boundary Layer

“…The same reasoning reverses when the blade points downwards, i.e., for azimuth angle between 180 • and 360 • . Qualitatively similar results were obtained in the literature [13,14].…”

“…Xin Shen et al [12] used an advanced lifting surface model to mimic the aerodynamics of the blade and also accounted for a sheared inlet wind velocity. Increasing the computational cost, Seydel and Aliseda [13] performed numerical simulations using a Reynolds-average Navier-Stokes (RANS) turbulence model (k-ω SST) in combination with a sliding interface approach to handle the relative rotation of the analyzed wind rotor; the ABL was approximated by a piece-wise linear wind velocity distribution. Similarly, Cai et al [14] adopted a RANS model, coupled with a sliding interface technique, to simulate the dynamics of a wind turbine with supporting structures immersed in the ABL, reproducing the wind velocity by a power law.…”

Development of a Computational System to Improve Wind Farm Layout, Part II: Wind Turbine Wakes Interaction

“…Storey et al [11] implemented a CFD model using a modified actuator technique to develop transient simulations, considering the NREL 5MW turbine. They achieved reduction in the computational time for the simulation while still keeping flow solution fidelity compared to the standard ADM. Seydel et al [12] performed a Reynolds Averaged Navier-Stokes (RANS) k-ω simulation of the NREL 5 MW to study wake effects between two wind turbines. Réthoré et al [13] investigated CFD techniques based on permeable body forces including: ADM, ALM, and the Actuator Surface Model (ASM).…”

Vėjo jėgainių keliamo triukšmo bei apsaugos priemonių tyrimas ir vertinimas

“…Už vėjo jėgainės susiformavęs oro sūkurys gali padidinti vėjo jėgainių efektyvumą. Tačiau tuo pat metu pulsuojantis srautas neigiamai veikia pavėjui stovinčios vėjo jėgainės vėjaratį, ko pasekmėje padidėja triukšmo emisijos bei galimi mechaniniai gedimai (Seydel andAliseda 2013, Hansen et al 2006). Yra atlikta nemažai vėjaračio kuriamų sūkurių tyrimų, kurių bendras tikslas -nustatyti turbulentinių sūkurių intensyvumą bei energijos nuostolius (Frandsen et al 2009;Sanderse et al 2011;Porte-Agel et al 2011;Li et al 2012;Churchfield et al 2012;Seydel and Aliseda 2013).…”