  The high-Reynolds-number wake of a slender body with a turbulent boundary
layer is investigated using a hybrid simulation. The wake generator is a 6:1
prolate spheroid and the Reynolds number based on the diameter $D$ is $Re =
10^5$. The transition of the unstratified wake to a state of complete
self-similarity is investigated by looking for the first time into the far
field of a slender body wake. Unlike bluff-body wakes, here the flow is not
dominated by vortex shedding in the near wake. Instead, the recirculation
region is very small, the near wake is quasi-parallel and is characterized by
the presence of broadband turbulence. The simulations show that these
particularities alter the decay rate of the wake significantly and challenge
the notion of universality -- the idea that far from the body all turbulent
wakes decay at the same rate. The influence of stratification in the wake is
also studied at Froude numbers $Fr=U_\infty/ND=2$ and $10$. The results imply
that the onset of buoyancy effects depends on the wake generator and that the
far wake retains information of the initial conditions.

Fluid Dynamics