Banca de DEFESA: Ramiro de Matos Bertolina

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Ramiro de Matos Bertolina
DATE: 19/10/2023
TIME: 14:00
LOCAL: Microsoft TEAMS
TITLE:

Influence of the pitch angle on the torque generation of H-Darrieus turbines

KEY WORDS:

Vertical Axis Wind Turbine (VAWT); Pitch Angle; Aerodynamic Interaction; Vorticity Wake; Dynamic Stall.

PAGES: 73
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

With the growing interest in wind energy in urban environments, vertical axis turbines are gaining prominence due to their low cost of installation and maintenance and their ability to operate in regions with constantly changing winds. However, these devices still face challenges in terms of their power coefficient, which is relatively low compared to horizontal axis turbines. One of the current lines of research to increase the performance of these turbines is the study of the pitch angle of their blades. The state of the art indicates an improvement in the power coefficient of up to about 10% by changing the pitch angle. This increase is attributed to the delay in the release of the dynamic stall vortex of the blades. However, in vertical axis turbines, each blade creates an individual wake. During turbine operation, the wake of one blade interacts with another blade. This
interaction affects its torque production, a phenomenon that has not been explored in the literature for vertical axis turbines. This research focuses on the changes that varying the pitch angle causes in he wake-blade interactions of H-Darrieus turbines. It also analyzes how varying the pitch angle alters the phenomenon of dynamic stall in the blades. To study these phenomena, URANS-type numerical analyses have been performed using the 𝜅−𝜔 SST turbulence model. In addition, the study includes theoretical approaches based on aerodynamic force data obtained using the panel method. The analyses have been carried out using configurations that include both three blades and a single blade. These multiple configurations make it possible to evaluate the differences between blade passage with and without wake interaction. The analysis of the wake interaction leads to the conclusion that changing the pitch angle causes an increase in the incidence of the boundary layer separation phenomenon and displaces the vortex that detaches from the blades,
changing the way it impacts the downstream blade. Applying these findings to a study of the pitch angle of the turbine, this research shows that changing the pitch angle to -5° causes an increase in the power coefficient of the turbine of 22%, 12% more than reported in the literature.

COMMITTEE MEMBERS:
Externo à Instituição - BRUNO SOUZA CARMO
Interno - 2245668 - MARIO BENJAMIM BAPTISTA DE SIQUEIRA
Externo ao Programa - 3295206 - RAFAEL CASTILHO FARIA MENDES - UnBPresidente - 3375759 - TAYGOARA FELAMINGO DE OLIVEIRA