Flow Visualization of Footballs to Analyze the Factors Affecting their Aerodynamic Performance Using CFD

Abstract

The motion of a football in air is influenced by the combination of various aerodynamic effects caused by the parameters such as velocity, surface roughness, panel orientation and shape. This paper analyzes the individual and combined effects of these parameters on the flight characteristics of various footballs using CFD Analysis. Four balls, a smooth sphere, a 32-panel conventional football, 14-panel Teamgeist and 6-panel Brazuca ball are subjected to different velocities of air flow over them, both in the laminar and turbulent regime, different surface roughness values and the influence of these parameters on the aerodynamics of the balls is evaluated by the drag force, drag coefficient and hydrodynamic boundary layer separation angle. The effect of the seam length, number of panels and panel orientation are also compared. The results of these effects are discussed later in the paper and are used to explain the knuckling effects and unpredictable trajectory of the Jabulani ball.