Numerical simulation of water-hammer in tapered pipes using an implicit least-squares approach

A technique using radial-basis functions and least-squares optimisation is applied for the numerical solution of one-dimensional equations governing transient pipe flow. The method can deal with geometrically non-uniform pipes by employing an arbitrary distribution of scattering nodes in the space domain. The formulation is implicit in time with a sparse and symmetric matrix equation to be solved at each time step. One tapered-pipe problem with available analytical solution is used for verification and one straight-pipe problem with available experimental data is used for validation. The effect of gradually clogged and swollen pipe sections on pressure wave propagation is investigated. The latter is of importance for transient-based fault-detection techniques.