Authors: Leonardo Olavarría and Pablo del Rio
Presented at: Tailings 2026
Paper Abstract
One-dimensional (1D) hydraulic design of tailings handling systems—Manning, h/Di filling criteria, Froude number, and energy balances—forms the basis of engineering practice and efficiently sizes
the global components of a typical hydraulic system. At certain nodes, however, the assumptions of the 1D approach break down: multi-branch diversion fittings, boxes with high-energy jets, variable cross-section transitions, and structures with air-tailings interaction generate phenomena that cannot be captured adequately by conventional analytical tools.
Four cases of computational fluid dynamics (CFD) application in real mining projects are presented, developed with OpenFOAM v12 in transient two-phase or multiphase mode: (i) gravitational
discharge spigots in series on a 36" HDPE main pipe; (ii) a "Y"-type diversion fitting in 42" HDPE; (iii) energy dissipation dropboxes on a DN 800 HDPE inlet pipe; and (iv) a thickener distribution box in an existing operation. The methodology is common to all four cases.
Four differentiated roles of CFD as a complement to 1D analysis are identified, a metric complementary to static criteria is proposed to evaluate the temporal stability of discharges, and a practical guide is derived indicating when CFD should be activated, based on criteria such as the limits of the 1D model, the absence of a reference cross-section, or the need to assess flow distribution, transient behaviour, or design verification.
