SearcharxivSearch

arXiv · 2407.20746

Large-Scale Horizontal Axis Wind Turbine Aerodynamic Efficiency Optimization using Active Flow Control and Synthetic Jets

Abstract

Efficiency increase is seen as one of the main goals in any energy converting device. In this direction, the present study aims to demonstrate that large-scale wind turbines can still be improved in order to generate larger amounts of energy. The research presented in this manuscript consists of two main blocks. Initially, it analyzes via Computational Fluid Dynamics (CFD) the boundary layer dynamics on a set of pre-determined airfoils cut along the DTU-10MW reference blade by using the 2D URANS k omega SST turbulence model. The aim of this initial stage is to identify the boundary layer separation point, its associated frequency, and peak to peak amplitude for each airfoil cut along the blade, evaluating as well their respective aerodynamic characteristics. The second main goal of the present research consists of implementing the Active Flow Control (AFC) technology and, when employing synthetic jets, to reattach the boundary layer in all airfoils where it is separated. To accomplish this second goal efficiently, the five parameters associated to the AFC implementation performed to each airfoil will be obtained through respective genetic algorithm optimizations. An energy assessment is finally undertaken at each airfoil to validate the respective energy gain obtained. When comparing the net power gain, before and after AFC implementation, generated by each of the airfoils evaluated, net power gains between 23 and 36KW are obtained in all airfoils analyzed, clarifying that the proposed technology is capable of improving the performance of the wind turbines, very likely at any operating condition.

Explore related subjects

Keep this discovery

BibTeXRIS

Ahmad Nabhani, Navid M Tousi, Marti Coma, Gabriel Bugeda, Josep M Bergada. 2024-07-30. Large-Scale Horizontal Axis Wind Turbine Aerodynamic Efficiency Optimization using Active Flow Control and Synthetic Jets. https://arxiv.org/abs/2407.20746

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Correlative effects of induced magnetic field-buoyancy on reactive solute dispersion dynamics in couple-stress fluids

We investigate the dispersion of a reactive solute in a couple-stress fluid flowing between two parallel plates under the combined effects of pressure-driven flow, buoyancy, and an induced magnetic field. The model incorporates first-order heterogeneous reactions at both channel walls alongside a bulk reaction. Using Mei's multiscale homogenization technique accurate to third order, we develop a higher-order asymptotic formulation to determine the effective longitudinal dispersion coefficient and concentration field. Analytical predictions are complemented by Brownian dynamics simulations and finite-difference solutions, while the Aris method of moments quantifies transient mean displacement, spatial variance, and effective dispersivity. The hydrodynamic analysis reveals a singular branch in the velocity solution when the Hartmann number equals half the couple-stress parameter and identifies a characteristic quarter-power scaling between the Hartmann number and couple-stress parameter, separating couple-stress- and magnetically dominated regimes. The model recovers classical Taylor-dispersion behavior in the non-reactive Newtonian limit and agrees well with experimental measurements. Couple-stress rheology and magnetic damping suppress shear-induced dispersion, whereas buoyancy enhances dispersion through additional transverse velocity gradients. A distinct saturation regime of the dispersion coefficient emerges with an increasing couple-stress parameter, while unequal wall absorption induces persistent transverse asymmetry, and stronger absorption enhances solute removal near the source. Numerical and stochastic results validate the analytical framework while resolving higher-order concentration structures and particle-scale wall adsorption.

physics.flu-dyn

DiffSWE2d: a differentiable Shallow Water Equations solver for end-to-end flood and tsunami modelling

Solving inverse and optimisation problems with traditional shallow water equations (SWE) solvers can be computationally expensive, particularly when gradients with respect to model inputs or parameters must be estimated through repeated forward simulations. In this paper, we introduce DiffSWE2d, an open-source differentiable shallow water equations solver for end-to-end flood and tsunami modelling implemented in PyTorch. By leveraging automatic differentiation, DiffSWE2d represents the time-marching physics as a differentiable computational graph, enabling gradients to be propagated directly through the numerical solver. We validate the solver against two established benchmark cases and demonstrate its application to tsunami waveform inversion, showing its ability to infer model inputs through gradient-based optimisation. DiffSWE2d provides a flexible framework for integrating physics-based hydrodynamic modelling with modern optimisation and machine learning methods. The source code and reproducible examples are publicly available at: https://github.com/ZhonghouXu/DiffSWE2d

physics.flu-dyn

Low inertia limit of elasto-inertial turbulence

Pipe and channel flows of viscoelastic fluids display chaotic dynamics at unusually low speeds, a phenomenon referred to as elasto-inertial turbulence, EIT. First reported in experiments a century ago, recent theoretical studies and model computations predict a variety of scenarios for the phenomenon's origin, ranging from hoop stress modes to center modes and to Tollmien-Schlichting waves. Lacking experimental confirmation, the relevant scenario in actual flows of polymer solutions remains unknown. We here determine the transition threshold of EIT in pipe experiments, covering three decades in elasticity number. Across this entire parameter range, the transition features center mode structures at onset. Eventually the instability diverges at a lower inertia (upper elasticity) limit, which is a robust signature of this center mode scenario. Finally, we report the first experimental observation of a traveling wave in viscoelastic pipe flow, and the sequences of localized structures found, are in excellent agreement with a center mode traveling wave, the "arrowhead" solution, discovered in model simulations.

physics.flu-dyn