Computations of breakup modes in laminar compound liquid jets in a coflowing fluid

► Breakup modes of an axisymmetric, laminar compound jet of immiscible fluids in a coflowing system are numerically studied. ► A front-tracking/finite difference method is used. ► Three modes: inner dripping-outer dripping, inner jetting-outer jetting and mixed dripping-jetting are found. ► Transition from dripping to jetting is investigated by varying various parameters.