  Stratified flows forced by internal waves similar to those obtained in the
Coriolis platform (LEGI, Grenoble, France) \cite{Savaro2020} are studied by
pseudospectral triply-periodic simulations. The experimental forcing mechanism
consisting in large oscillating vertical panels is mimicked by a penalization
method. The analysis of temporal and spatiotemporal spectra reveals that the
flow for the strongest forcing in the experiments is composed of two superposed
large and quasi-steady horizontal vortices, of internal waves in box modes and
of much weaker waves outside the modes. Spatial spectra and spectral energy
budget confirm that the flow is in an intermediate regime for very small
horizontal Froude number $F_h$ and buoyancy Reynolds number $R$ close to unity.
Since the forcing frequency $\omega_f$ is just slightly smaller than the
Brunt-V\"ais\"al\"a frequency $N$, there are energy transfers towards slower
waves and large vortices, which correspond to an upscale energy flux over the
horizontal.
  Two other experimentally feasible sets of parameters are investigated. A
larger amplitude forcing shows that it would indeed be possible to produce in
huge apparatus like the Coriolis platform stratified turbulence forced by waves
for small $F_h$ and buoyancy Reynolds number $R$ of order 10. Forcing slower
waves for $\omega_f = 0.40 N$ leaves space between $\omega_f$ and $N$ for
"down-time-scale" transfers through weakly nonlinear interactions with temporal
spectra consistent with $\omega^{-2}$ slope. However, for this set of
parameters, the large scales of the flow are strongly dissipative and there is
no downscale energy cascade.
