Modeling Tees and Manifolds in Networks

Rigorous modeling of combining and dividing flow through tees improves solutions for steady and unsteady flow in pipe networks dominated by tee losses and in pipe networks, such as navigation lock filling and emptying systems, where distribution of flow through a manifold is of interest. Every tee has two flow paths with different loss, or tee, coefficients for each path. Rigorously modeling a tee means varying the tee coefficients with the split in flow through the tee and accounting for changes in velocity head in each flow path. The general purpose computer code TFSIM provides diverging_tee and converging_tee components for rigorous modeling of tees in pipe networks. A manifold with relatively few branches or portholes can be modeled as a header pipe with a series of tee components spread along its length. However, this approach becomes impractical for manifolds with many, perhaps hundreds, of branches. TFSIM provides diverging_manifold and converging_manifold components that model multiple, identical tees in one component. Several of these manifold components distributed along the length of a header pipe can be used to represent a manifold with hundreds of physical branches. Discharges predicted using manifold components agree closely with those predicted using individual tee components for every branch.