Ahmad Nazari Gazik - B.Sc. student in mechanical engineering, Ferdowsi University of Mashhad, Mashhad,
Sobhan Keikha - B.Sc. student in Aerospace engineering, Ferdowsi University of Mashhad, Mashhad,
Kourosh Mojarab Naei - B.Sc. student, Ferdowsi University of Mashhad, Mashhad,
AbdolHasib Allahyari - B.Sc. student in mechanical engineering, Ferdowsi University of Mashhad, Mashhad,
Farbod Salehi P. - B.Sc. student in mechanical engineering, Ferdowsi University of Mashhad, Mashhad,
Mohammad Hassan Djavareshkian - Professor, Ferdowsi University of Mashhad, Mashhad,

The main purpose of the upcoming article is to investigatethe effects of using a blade with two NACA ۰۰۱۵ airfoilswith a geometric ratio of ۰.۵ on the output power of avertical-axis wind turbine exposed to wind with a constantspeed of ۱۰ m/s at different rotational speeds.Initially, creating a suitable strategy for the numericalsimulation of a straight-blade vertical axis wind turbineusing a ۲D mesh has been discussed. This ۲D simulationwas done via Ansys ۲۰۲۱ commercial software and resultswere verified with experimental results. Special settingshave been used to solve the issue of not modeling theairfoil edge vortices in a ۲D simulation and minimize itseffects. Although in addition to the errors of a ۲Dmodeling, the Reynolds-averaged Navier-Stokes (RANS)solvers have errors compared to the Direct NumericalSimulation method, however different settings andmodeling have been used to extract closest results toexperimental data. Additionally, the sliding meshtechnique has been utilized, which provides lowercomputational cost than the moving mesh technique. Theresult of this numerical solution has ۹۰% accuracy relativeto simulation using SST K-ω model.Following, based on the validated results and usingsimilar settings, the effects of using double-airfoils in twodifferent modes have been investigated and the resultshave been compared with the single airfoil turbine.Ultimately, the power factor at different rotational speedshas been checked for single and double-airfoil turbines,which indicates the power factor of the turbine hasincreased by ۱۲% on average.

Vertical Axis Wind Turbine, Renewable Energies,Numerical Simulation, Computational Fluid Dynamics,Aerodynamics