Numerical simulation on pump as turbine: Mesh reliability and performance concerns

A pump used as turbine (PAT) for the transformation of hydraulic energy in electricity is the new trend in the management of water distribution networks. So far few application of such devices are known for the lack of adequate studies on the PAT project and on the interactions between PAT and the water system. Overall efficiency, flexibility under flow rate and pressure variations, response to unsteady state conditions are still open questions. Some of these problems are discussed in the paper by numerical computation.