M.Sc Thesis


M.Sc StudentYair Moryossef
SubjectA Computational Study of a Wing in Ground Effect
DepartmentDepartment of Aerospace Engineering
Supervisor Dr. Levy Yuval


Abstract

Numerical simulations are conducted to study the flow field about a wing in ground effect. The flow fields about wings in ground effect are of great interest, especially concerning open-wheel race-cars front-wings. Open-wheel race-car front-wings, are highly cambered and inverted. The wings are used to produce negative lift (down-force), upon the front part of the car. A typical down-force created by the front wing is approximately $30\%$ of the total down-force that the car creates.


The simulations cover fixed wing simulations and oscillating wing simulations about three- and two-dimensional wings, in and

out of ground effect. The motion is a typical oscillatory heaving motion that a front wing experiences due to the car suspension motion.


The results show strong ground effect on both the lift and the drag. The results from the fixed wing simulations for inviscid flow show that the lift increase continuously as the wing approaches the ground. However, the assumption of inviscid flow at the extreme ground effect is incorrect. The inviscid assumption is especially incorrect at the gap region between the ground and the wing suction side (lower side). The simulations of a fixed wing in ground effect in viscous flow reaffirm the so-called down-force reduction phenomenon. Meaning that there is a reduction in the down-force in heights lower than a specific height. 


The oscillating wing simulations show a nonlinear behavior that strengthens in ground effect. It is known that under certain conditions, an oscillating wing creates thrust. the

results show that as the ground clearance decreases the thrust

increases. Moreover, there is a unique relation between the thrust and

the frequency in ground effect.