Abstract
A practical numerical simulation model is presented for the underground drainage network system with a large scale drainage pumping station. In this model, the hypothetical slot at the crown of the pipe is installed to analyze the pressurized flow, and the MacCormack scheme for numerical solution technique is applied to simulate the mixed flow condition of sub-critical and super-critical flow. The model is verified by comparison with monitoring water levels of laboratory tests and exiting drainage network system with pump station. From these calculation results, it is shown that the simulation model is very useful to simulate unsteady free surface-pressurized flows and surge phenomenon of the pipe network system including the steep slope pipe
