1. A numerical analysis device that performs transient analysis for analyzing temporal changes in physical quantities of a fluid by using a volume junction method, based on a pipeline network model constructed as a 3D model of a pipeline network that includes fluidic devices and pipes, the numerical analysis device comprising: a selection unit for selecting a fluidic device model and a pipe model used for the transient analysis from among fluidic device models and pipe models that are located between a start point and an end point set in the pipeline network model, which is constructed in advance; a division unit for dividing the fluidic device model and the pipe model selected by the selection unit into a plurality of volume elements that indicate volumes of the fluidic device model and the pipe model and into a plurality of junction elements that indicate boundaries between the volume elements and that indicate increases or decreases in kinetic energy of the fluid; and a deriving unit for deriving the volumes of the respective volume elements obtained by the division unit and coefficients that indicate a magnitude of pressure loss corresponding to the respective junction elements, based on a shape of the fluidic device model, a shape of the pipe model, and the physical quantities of the fluid flowing in the pipeline network model, for associating the derived volumes with the volume elements, and for associating the derived coefficients with the junction elements.