2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/222274Consider a fluid flowing through a junction between two pipes with different sections. Its evolution is described by the 2D or 3D Euler equations, whose analytical theory is far from complete and whose numerical treatment may be rather costly. This note compares different 1D approaches to this phenomenon.21 pages, 6 figuresAnalysis of PDEsMathematical Physics35L65text