Effect of the opening and location ratio on the performance of an H-Darrieus VAWT

Revista Facultad de Ingeniería, Universidad de Antioquia, No.104, pp. 33-41, Jul-Sep 2022 Effect of the opening and location ratio on the performance of an H-Darrieus VAWT Efecto de la relación de abertura y ubicación en el rendimiento de una H-Darrieus VAWT Andrés Burbano-Hernández 1* , Diego Hincapié 1 , Jonathan Graciano-Uribe 1 , Edwar Torres-López 2 1 Departamento de Ingeniería Mecatrónica, Grupo de Investigación MATyER, Instituto Tecnológico Metropolitano. Calle 73 # 76A-354, Vía al Volador. C. P. 050034, Medellín, Colombia. 2 Departamento de Ingeniería Mecánica, Universidad de Antioquia. Cl. 67 # 53-108. C. P. 050010, Medellín, Colombia. ABSTRACT: Vertical axis wind turbines such as Darrieus turbines are a very interesting CITE THIS ARTICLE AS: A. Burbano, D. Hincapié, J. Graciano and E. Torres. ”Effect of the opening and location ratio on the performance of an H-Darrieus VAWT”, Revista Facultad de Ingeniería Universidad de Antioquia, no. 104, pp. 33-41, Jul-Sep 2022. [Online]. Available: https: //www.doi.org/10.17533/ udea.redin.20210737 ARTICLE INFO: Received: October 30, 2020 Accepted: July 16, 2021 Available online: July 16, 2021 KEYWORDS: H-Darrieus; Airfoil; ratio; CFD; NACA; Efficiency H-Darrieus; Perfil aerodinámico; Proporción; CFD; NACA; Eficiencia category of low wind speed domestic wind turbines. Further research work is needed to enhance their efficiency to fulfill the higher demand in small applications for power generation. The main objective of this work is to find a Darrieus turbine design to boost the starting capacity of the turbine through an opening located at the lower surface of the airfoil. We carried out a thorough CFD (Computational Fluid Dynamics) investigation to determine the impact of the opening position on the Darrieus rotor’s output. This new type of airfoil uses a standard NACA 0015 profile and a profile with an opening on the lower surface of the profile. Different sizes of the opening in a symmetrical profile are evaluated through the CFD method to predict the Cp and CT of this H-Darrieus turbine design. Five sections were designed to describe the research of this new H-Darrieus rotor. Generally speaking, the results showed that the Cp decreases with the opening ratio, the desirable rotors with the lower surface opening ratio are 0.12 to 0.36 considering this with the low Cp LP . RESUMEN: Las turbinas eólicas de eje vertical como las turbinas Darrieus son un tipo muy interesante de turbinas eólicas domésticas con bajas velocidades de viento. Se necesita más trabajo de investigación para mejorar su rendimiento a fin de satisfacer la mayor demanda de generación de energía en aplicaciones pequeñas. El objetivo principal de este trabajo es encontrar un diseño de una turbina Darrieus para mejorar la capacidad de arranque de la turbina a través de una abertura situada en la superficie inferior del perfil. Se llevó a cabo una investigación de CFD (Dinámica de Fluidos Computacional) para determinar el impacto de la posición de la abertura en la salida del rotor Darrieus. Este nuevo tipo de perfil aerodinámico utiliza un perfil estándar NACA 0015 y un perfil con una abertura en la superficie inferior del perfil. Los diferentes tamaños de la abertura en un perfil simétrico se evalúan a través del método CFD para predecir el Cp y CT de este diseño de turbina H-Darrieus. Se diseñaron cinco secciones para describir la investigación de este diseño de H-Darrieus. En términos generales, los resultados mostraron que el Cp disminuye con la relación de apertura, los rotores deseables con la relación de apertura son de 0,12 a 0,36 considerando esto con el bajo el criterio de un menor Cp LP . * Corresponding author: Andrés Burbano-Hernández E-mail: ISSN 0120-6230 e-ISSN 2422-2844 33 DOI: 10.17533/udea.redin.20210737 33 C. González-Morales et al., Revista Facultad de Ingeniería, Universidad de Antioquia, No. 104, pp. 33-41, 2022 1. Introduction The global contribution of buildings to energy use, both residential and commercial, has gradually risen in developing countries, exceeding figures between 20% and 40%, and has surpassed other primary industries: manufacturing and transport industries. Development in the population, growing demand for housing facilities and comfort levels, and increasing time spent within houses would ensure that the upward rise in energy demand persists in the future [1]. Residential and industrial consumption of energy is increasing at an annual rate of 0.4% to 0.5% per annum from 2018 to 2050 [2], according to the US EIA (Energy Information Administration) evaluation. The use of renewable energies would also be an indicator of a viable future for energy development in houses. In the urban area, small or micro-wind turbines have lately gained more interest. There are some benefits of integrating wind turbines into buildings. The electricity generated by the wind turbine can be fed directly into the building’s electrical circuits, which could minimize the expense of linking the distribution network to the local grid and eliminate losses in energy transport. Several efforts have been made to make a structured grouping of wind turbines coordinated, but this provides a slight advantage as their practical utility drastically reduces the number of basic designs. Wind turbines are classified based on their aerodynamic functions, followed by the turbine’s configuration and construction. The aerodynamic function of the rotor is defined by whether the wind turbine derives its power primarily from the rotor-acting air stream’s aerodynamic drag or whether it is capable of capturing the aerodynamic lift produced by the flow across streamlined bodies. In particular, several attempts have been made in Germany, the US, and the UK to grow and refine this form to commercial maturity. Musgrove (British Engineer) suggested straight blades as H-rotors with variable rotor geometry to control the strength and turbine RPM. However, the cost of this principle is still high as compared with horizontal-axis rotors. The Darrieus H-rotor turbine [3] was developed by a German manufacturer and had features such as a basic structure and a generator, which are directly built into the rotor without using a gearbox. VAWTs, particularly the Darrieus lift-type rotors, appear to be the most suitable turbines in the building environment because of their unique properties, independent of wind direction, low noise, and vibration intensity. Some studies have shown that in skewed flow and horizontal wind turbines, H-Darrieus produces higher power output but suffers from a decrease in power [4]. Figure 1 Darrieus turbine airfoil flow velocities 2. Turbine description The wind flow flows over the turbine blades composed of an airfoil cross-section profile to create beneficial torque and power. A relative velocity W is produced, as with any airfoil, due to a vector difference between absolute wind velocity Va and peripheral blade velocity u, as (...truncated)