  Recent observations as well as theoretical studies of YSO jets suggest the
presence of two steady components: a disk wind type outflow needed to explain
the observed high mass loss rates and a stellar wind type outflow probably
accounting for the observed stellar spin down. In this framework, we construct
numerical two-component jet models by properly mixing an analytical disk wind
solution with a complementary analytically derived stellar outflow. Their
combination is controlled by both spatial and temporal parameters, in order to
address different physical conditions and time variable features. We study the
temporal evolution and the interaction of the two jet components on both small
and large scales. The simulations reach steady state configurations close to
the initial solutions. Although time variability is not found to considerably
affect the dynamics, flow fluctuations generate condensations, whose large
scale structures have a strong resemblance to observed YSO jet knots.
