• axisymmetric
• drag reduction
• fluid mechanics

This thesis, carried out in collaboration with the Queen Mary University of London, has the aim of study drag reduction devices for axisymmetric bodies using both experiments on wind tunnel and numerical flow simulations.
Models used for wind tunnel experiments were a 4:1 ellipsoid, with the possibility to replace the rear section with a conic boat tail and a 4:1 prolate ellipsoid; this last model was equipped with an internal fan and modified with an intake at the rear for wake aspiration and a conic mid-section in order to perform boundary layer blowing from an annular slot.
Results show how the presence of a conic boat tail lead to a reduction of the form drag and boundary layer suction/wake aspiration have great impact on reducing both viscous and form drag. In this latter case it is suggested, as a future development, a study of the ratio between power saved from the drag reduction and power used by active drag reducing device.
CFD main result is that the numerical predictions are capable to follow the experimental trend just with K-Omega SST turbulence model.