Performance enhancement of Savonius wind turbine through partially deformable blades

In this study, we employ partially deformable blades to elevate the performance of Savonius wind turbines. The Bucket is constructed with rigid components equipped with a guidance system, resulting in continuous changes in its shape during turbine rotation. As the trailing edge of the advancing blade expands, it creates an active slot, effectively correcting the Bucket’s pressure distribution and enhancing the positive torque generated by the turbine. We employ a two-dimensional (2D) numerical model, implemented using the commercial software ANSYS-Fluent 23.0, with the governing motion equation executed through a user-defined function (UDF). This investigation explores the mechanism of performance enhancement by varying expansion amplitudes Our results, obtained at a Tip-speed ratio (TSR) of 1, reveal that when the amplitude of deformation exceeds one-quarter of the Bucket radius, the partially deformable blade outperforms the rigid blade, leading to a remarkable 32% improvement in the torque coefficient. These findings signify a promising path toward enhancing Savonius turbine efficiency

ETUDE DE SYSTEME DE RECUPERATION D’ENERGIE PAR ASSOCIATION DE PALES BATTANTES AUX PALES D’EOLIENNE DE PROFILE NACA

Dans le cadre de cette thèse, différents stratégies de contrôle d‟écoulement sont proposées pour améliorer les performances des turbines à axe vertical. La première stratégie est une turbine avec des pales flexibles, différents types de déformations sont étudiés. La deuxième stratégie est un contrôle par des ailes battantes. Une meilleure compréhension du comportement d'écoulement complexe à travers les turbines a été achevée. L'objectif ultime est de proposer un modèle robuste et efficace de VAWT. L'efficacité d'extraction d'énergie a été améliorée

Efficiency Improvement of Darrieus Wind Turbine Using Oscillating Gurney Flap

In this work, a new model of Darrieus wind turbines with an oscillating gurney flap (OGF) is proposed. A detailed 2D computational fluid dynamics (CFD) investigation is carried out using ANSYS-Fluent 22.0 to assess the turbine performance. The OGF can alter its position between the upper and lower blade surfaces during the turbine rotation. Equations related to the combined motion are implemented through a user-defined function (UDF). The proposed model is validated where a good coincidence is achieved. The overset dynamic mesh method is used. It was found that a judicious synchronization of OGF and turbine blades creates beneficial vortex interactions, which correct the pressure distribution and lead to an overall improvement in the lift force. The magnitude of the improvement is highly dependent on the OGF length and the phase motion φ. The average torque coefficient Cm for the controlled case increased by more than 19% in comparison with the nominal case