Investigation on the Influence of Vortex Generators on Aerofoil

Abstract

Boundary layer separation is a major cause of concern in the wind turbine and aerospace industries as it adversely affects the performance of aircraft wings and wind turbine blades. The immediate result of flow separation over an aerofoil causes decrease in lift and an increase in drag within the stall range, both of which have a negative impact on the overall performance of aerofoils in the wind turbines. To overcome this problem, vortex generators (VGs) are used for increasing lift force and thus increasing the rotational speed of the blade. They act like small protrusions on wing surfaces which helps in energizing the boundary layers thereby delaying the separation and providing a wide range of attached flow over aerofoil surface. The present research illustrates the comparative analysis on the various shapes of VGs such as rectangular, triangular and gothic by varying the angle of attacks (AoA) from 0-15. The analysis is performed on NACA0012 aerofoil, which is developed using SOLIDWORKS and analysed on ANSYS 2020 R2 software. The values of lift (Cl) and drag (Cd) coefficients with and without VGs are determined using ANSYS fluent and the contours for velocity and pressure are further mapped using CFD Post. The stall angle is evaluated for each of the VG shapes representing the maximum lift that an aerofoil can achieve. Pressure coefficient plots are studied in order to investigate the amount of pressure difference created and its influence AoA at the leading edge of the aerofoil. An overall comparison is made to determine the best VG shape that delivers maximum lift to the aerofoil. The optimum configuration found for VG is gothic shape which illustrates the maximum lift coefficient value, which is highest amongst all the three shapes.