Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman A modified novel blade configuration proposal for a more efficient VAWT using CFD tools Iván Ostos a, ⁎ , Iván Ruiz a , Maja Gajic b , William Gómez a , Adriana Bonilla a , Carlos Collazos c a Grupo de Investigación en Aplicabilidad Tecnológica, Universidad Manuela Beltrán, Bogotá 110231, Colombia b School of Engineering, RMIT University, Melbourne 3073, Australia c Grupo de Ciencias Básicas y Laboratorios, Universidad Manuela Beltrán, Bogotá 110231, Colombia ARTICLE INFO Keywords: Savonius CFD Renewable energy Wind energy Turbulent model Novel configuration ABSTRACT It is a priority to generate affordable and reliable energy with higher participation of renewable energy tech- nologies into the global energy mix to provide efficient sustainable energy services for everyone, highlighting the need to focus on vulnerable communities in developing countries with limited or no access to electricity. Vertical axis wind turbines (VAWT) are widely used for renewable electricity generation. In that order, Savonius rotor, being a VAWT, is commonly used because of its numerous advantages for small scale generation. Thus, wind energy research on a modified Savonius rotor might be a feasible solution for powering vulnerable communities with no access to the grid. Hence, this paper shows how to improve the performance of a conventional Savonius blade by introducing a novel configuration without expensive and complex modifications on the geometry. For that purpose, a C m and C p coefficients comparison between 13 proposed scenarios against the conventional configuration to define a novel one, with better performance is carried out through a 2D computational fluid dynamic analysis by using Ansys Fluent 18.0. The SST k-ω model is selected as the turbulent model. As a result, a higher performance Savonius novel rotor configuration is identified with 17.81% improvement over the con- ventional configuration. 1. Introduction Nowadays, there are crucial aspects at the global scale that should not be addressed separately but in conjunction since they are con- sidered world priorities to reach energy security worldwide [1,2]. Po- pulation experience energy poverty with limited or no access to elec- tricity, [3] combined with a global fossil fuel crisis and dependency [4], present a real need for actions. It is imperative to generate inclusive sustainable projects that would create alternatives to improve quality life standards for the vulnerable communities [5,6]. On the 25th of September of 2015, the United Nations (UN) issued a committed proposal of an idealistic world expected to become a reality by 2030. This ambitious initiative is based on 17 SDGs (sustainable development goals), targeting to eradicate extreme hunger and poverty conditions worldwide before 2030 [7]. This paper fits in with aiming to meet goal number seven (to guarantee universal access to clean, af- fordable and reliable energy) [8] and the goal number thirteen (to combat climate change) [9]. In consequence, more efficient and reliable renewable energy sources are required to contribute to the consolida- tion of the SDGs of interest. A VAWT (Vertical Axis Wind Turbine) Savonius type is selected because of its lower construction, installation and maintenance costs; it has independency on wind direction, presents lesser wear on moving parts and its wake effect is considered limited. Savonius has a re- spectable starting torque at low wind speeds, it also may operate at low wind speeds producing bearable to low noise level. It is considered to be a more bird and bat-friendly rotor than other turbine types, suitable for affordable small wind projects [10,11]. Savonius turbines have a robust body, their mechanical systems can be installed close to ground level. They generally consist of a semi-circular “S” shaped cross segment pair of blades with a characteristic overlap in between ; since less drag is involved moving along the wind, then the drag variance assists the turbines to spin [12,13]. Due to Savonius turbines most significant qualities, a higher self- starting torque than other VAWT, they can be use not only for power generation at low wind speeds but as a starter for lift-type VAWT with poor starting performance. Even so, the situation has not been studied extensively, authors such as [14] have proposed the addition of Savo- nius rotor to lend its self-starting proficiency to a Darrius rotor ex- pecting to achieve better operating conditions that would allow the https://doi.org/10.1016/j.enconman.2018.11.025 Received 8 August 2018; Received in revised form 8 November 2018; Accepted 11 November 2018 ⁎ Corresponding author. E-mail address: iostos83@gmail.com (I. Ostos). Energy Conversion and Management 180 (2019) 733–746 0196-8904/ © 2018 Elsevier Ltd. All rights reserved. T