  The evolution of shocks induced by massive stars does not depend only on the
ambient magnetic field strength, but also on its orientation. In the present
work, the dynamics of a magnetized blast wave is investigated under the
influence of both azimuthal and axial ambient magnetic fields. The blast wave
is driven by a central source and forms a shell that results from the
accumulation of interstellar matter behind the shock front. A similarity form
of the ambient magnetic field and a cylindrical geometry of the blast wave are
assumed to obtain self-similar solutions. The model is studied separately for
both azimuthal and axial magnetic field and applied to stellar wind bubbles and
supernova remnants respectively, using 1D numerical simulations. We found that
the magnetized blast wave differs from the self-similar case without an ambient
magnetic field. The forward shock front goes slower in the azimuthal case and
faster in the axial one. For both tangential orientations, the thickness of the
shell increases with the magnetic strength. In the azimuthal case, the thermal
energy can be converted to magnetic energy near the inner boundary of the
shell. Thus, the temperature drops and the magnetic field increases at the
tangential discontinuity of the stellar wind bubble. In the axial case of a
supernova remnant, the numerical solution al w ays follows a special curve in
the parameter space given by the self-similar model.
