Visualization and Analysis of Airfoil Flow Model Using Vape Fluid with Low Speed Wind Tunnel

The flow visualization test of the smoke method is carried out to determine the characteristics of the airflow around the test model at a certain angle of attack and speed in the Indonesian Low-Speed Wind Tunnel (ILST) so far using a smoke nozzle directed at the part of the airflow to be observed. Along with the development of aerodynamic technology, research was carried out using several smoke nozzles so that the characteristics of the airflow around the test model could be observed simultaneously. This experiment was carried out in a wind tunnel with a test section size of 300 × 300 × 680 mm by analyzing the flow visualization of the airfoilAirfoil model using vape fluid. The test model used a three-dimensional NACA 4412 airfoilAirfoil profile, structural material made of 10 mm thick plexiglass, skin covered with epoxy resin with dimensions of chord length (C) = 151.57 mm, span width (S) = 300 mm, maximum thickness (t) = 19.18 mm was made on a laboratory scale for testing purposes in a wind tunnel. Flow visualization research was carried out at angles of attack (α) 0°, 5°, 10°, 15° and 20° at wind speeds of 20, 15, and 10 m/s and 5 m/s, then analyzed visually flow with the smoke method to see changes as the angle of attack (α) increases. The results showed that the lift coefficient (CL) obtained by a numerical approach or testing in a wind tunnel from the data of previous researchers with this flow visualization study changes in the angle of attack (α) have an effect on the leading edge area on the surface of the airfoilAirfoil body, which in turn affects the overall aerodynamic characteristics. From the results of the photo, it can be seen that the greater the difference in flow between the upper and lower sides of the airfoilAirfoil body, the greater the lifting force resulting in a change in flow from laminar to turbulent flow after passing through the trailing edge. Changes in the angle of attack affect the vortex on the trailing edge.