Spatial development of wakes using a spectral multi-domain method

A spectral Chebyshev method for the computation of wakes in stratified fluids is presented. It is based on a divergence-free multi-domain solver of the generalized Oseen problem which results from the discretization in time of the Navier-Stokes equations, when taking into account implicitly the part of the convective term associated with the mean flow velocity. Specific soft outflow boundary conditions are suggested, to get in the upstream direction a fast decay of the error induced by the truncation of the physical domain. Finally, numerical results are produced to point out the influence of a stable thermal stratification.