  We perform relativistic hydrodynamic simulations of internal shocks formed in
microquasar jets by continuous variation of the bulk Lorentz factor, in order
to investigate the internal shock model. We consider one-, two-, and flicker
noise 20-mode variability. We observe emergence of a forward-reverse shock
structure for each peak of the Lorentz factor modulation. The high pressure in
the shocked layer launches powerful outflows perpendicular to the jet beam into
the ambient medium. These outflows dominate the details of the jet's kinetic
energy thermalization. They are responsible for mixing between the jet and
surrounding medium and generate powerful shocks in the latter. These results do
not concur with the popular picture of well-defined internal shells depositing
energy as they collide within the confines of the jet, in fact collisions
between internal shells themselves are quite rare in our continuous formulation
of the problem. For each of our simulations, we calculate the internal energy
deposited in the system, the "efficiency" of this deposition (defined as the
ratio of internal to total flow energy), and the maximum temperature reached in
order to make connections to emission mechanisms. We probe the dependence of
these diagnostics on the Lorentz factor variation amplitudes, modulation
frequencies, as well as the initial density ratio between the jet and the
ambient medium.
