International Journal of Latest Engineering and Management Research (IJLEMR) ISSN: 2455-4847 www.ijlemr.com || Volume 07 - Issue 04 || April 2022 || PP. 01-04 www.ijlemr.com 1 | Page Investigation the effect of various vortex generator types at different velocities and angles of attack in NACA 2412 Airfoil on lift and drag coefficients Ansam Adil Mohammed 1 , Qays Salman Kadhim 1 Mechanical Engineering Department 1 , College of Engineering, Al-Nahrain University, Baghdad, Iraq Abstract: Flow separation near the rear end of the aerodynamic body is the main cause of an increase in aerodynamic drag and a decrease in aerodynamic lift, for that they put a device known as vortex generator (VG) to controlling the flow separation. The vortex generator (VG) is an aerodynamic device, it activating the slow boundary layer motion and modifies the flow about the surfaces which results control of flow separation. Therefor the present work focused on the benefit of the various form of vortex generator (VG) such as rectangle, triangle, and gothic by using different angle of attack (0°,5 0 ,10 0 ,12 0 ,13 0 ,14 0 ,15 0 ,16 0 and 17°) at three different velocities (30, 35 and 40 m/s) for numerical test and (30 and 35 m/s) for experimental test to each one from these vortex generators, the main aim that implemented is comparative analysis for these types to find the best form in specific situation which in turn leads us to compared the values of the lift and drag coefficient for these different shapes of vortex generator (VG) and the most efficient form is given for each velocity and each angles of attack. This in detail study was performed on the NACA 2412 cambered airfoil. To find the better result of different types vortex generator (VG) to determine the value of lift and drag force and the value drag and lift coefficient from the above shapes which designed with the wing by Computer Aided Design (CAD). Keywords: Aerodynamics, Boundary Layer, flow separation, Vortex Generators, Drag Coefficient, Lift Coefficient. Introduction "One of the most prominent causes of drag on bodies in motion through a viscous fluid is flow separation near the rear of the body and at abrupt changes in its geometry"[1], when the flow in the boundary layer is retarded to a point where it can no longer counteract the pressure gradient and separates from the surface that was flow separation. Fluid flow control is a rapidly developing major of fluid dynamics which include involves simple or complex modification of the composition which in turn leads to great engineering benefit like reduce drag, increase lift, improve mixing or reduce noise, this modification may be done by passive or active devices. Passive devices are steady and require no energy. Active control requires actuators which may be driven in a time-dependent manner and require energy [2]. Passive techniques include geometric shaping, using the traditional vortex generators and the placement of longitudinal grooves or rib lets on airfoil surfaces, while the active techniques include steady suction or blowing, unsteady suction or blowing and the use of synthetic jets.This study focused on demonstrating the effect of different types of vortex generators on the characteristics of aerodynamic flow at different speeds and angles of attack, with both numerical and experimental parts, therefore, three forms of traditional vortex generators (rectangle, triangle, and gothic) were selected with angles of attack (0 0 ,5 0 ,10 0 ,12 0 ,13 0 ,14 0 ,15 0 ,16 0 and 17 0 ) at three velocities for numerical test (30, 35 and 40 m/s) and two velocities for experimental test (30 and 35 m/s) to explain their effects on a rectangular wing with profile NASA 2412. The solution approach used by ANSYS Fluent called the iterative solutions using for the numerical test, The value of drag and lift force can be taken by using result of CFD, also been added output of CFD simulation of contours of velocity and pressure, surface pressure and streamlines flow for NACA 2412 wing. The boundary conditions for ANSYS analysis at the input and output are given as the default domain. Three-dimensional steady turbulent flow of standard SST k-ω turbulence model had been solved with poly-hexcore mesh to compute the flow around the wing. Experimental tests for the wing and various types of vortex generators tested in low-speed wind tunnel of (0.7m × 0.7m × 1.5m) rectangular test section. The wing had been manufactured using plastic material using three-dimensional printing technologies. The experimental lift and drag forces were measured by three component balance devices.From the numerical results for lift and drag coefficient notes the Gothic VG has better effect at angle of attack less 140 in all velocities but at angle of attack more than 140 the Triangular VG the best but from the experimental results we note that the Gothic shapes have a better effect than the rest of the shapes in a broader perspective and they have efficiency in improving the properties when compared to the others. The numerical and experimental comparing results show that lift to drag ratio increases with using VGs than without VGs, the numerical CL/CD for the rectangular wing with and without VGs is