  High-mass microquasars may produce jets that will strongly interact with
surrounding stellar winds on binary system spatial scales. We study the
dynamics of the collision between a mildly relativistic hydrodynamical jet of
supersonic nature and the wind of an OB star. We performed numerical 3D
simulations of jets that cross the stellar wind with the code Ratpenat. The jet
head generates a strong shock in the wind, and strong recollimation shocks
occur due to the initial overpressure of the jet with its environment. These
shocks can accelerate particles up to TeV energies and produce gamma-rays. The
recollimation shock also strengthens jet asymmetric Kelvin-Helmholtz
instabilities produced in the wind/jet contact discontinuity. This can lead to
jet disruption even for jet powers of several times $10^{36}$ erg s$^{-1}$.
High-mass microquasar jets likely suffer a strong recollimation shock that can
be a site of particle acceleration up to very high energies, but also
eventually lead to the disruption of the jet.
