2-D modelling of effect of free-stream turbulence on trailing edge vortex

Abstract

Vorticity causes many adverse effects on the area near the surface, both on moving (turbine blade) and fixed objects. Therefore, this study attempts to investigate the effects of free-stream turbulence on trailing edge vortex on the NACA 0015 airfoil profile. This research was conducted using two-dimensional numerical simulations. To determine the interaction of vortex and free stream turbulence, two variations of turbulent intensity were given, namely 0.5% and 4.6% with Reynolds number of 1.6 x 105. The k-ε turbulence model was used in the current study. The angle of attack of the flow towards the airfoil was varied from 0 to 25 in conditions of increase and decrease in the horizontal position of the airfoil. The result was found that there is an agreement between the simulation and the experiment result. Increased turbulent intensity can delay the stall condition, the stall process begins to be observed after the 12 attack angle at 0.5% turbulent intensity while at turbulent intensity 4.6% the stall process was found after the 15 attack angle. From a velocity streamline, it was found that an increase in turbulent intensity can inhibit vortex growth.