Ground effect phenomena about lift and downforce generating cambered aerofoils

Investigations into ground effect phenomena about aerofoils are typically conducted on either an upright (lift‐producing) or inverted (downforce‐producing) configuration, in isolation. This limited approach does not promote a holistic understanding of how ground effect influences aerofoils. This paper aims to address this issue.

A two‐dimensional computational fluid dynamics investigation was conducted on the highly cambered Tyrrell aerofoil, in both its upright and inverted configurations, in order to better understand ground effect phenomena by observing how it influences each configuration differently. The trends in force and flow field behaviour were observed at various ground clearances through observation of the normal and drag forces and pressure coefficient plots. The aerofoil was held stationary and at a constant angle of attack of 6 degrees, with a moving ground plane to simulate the correct relative motion.

The different ground effect mechanisms that occur on each configuration are highlighted and explained. It is shown how ground effect manifests through these different phenomena and that there are general or overarching mechanisms that influence both configurations. These general mechanisms allow unintuitive phenomena, such as the downward movement of the stagnation point on both configurations, to be explained.

Overarching mechanisms of ground effect are discovered which are of value in any situation in which ground effect aerodynamics is to be exploited.