Water hammer analysis that uses the impulse response method for a reservoir-pump pipeline system

Abstract

This study analyzes the theoretical development of the impact of centrifugal pumps on pipeline systems using an impulse response method. The homologous relationships between the rotational speed of a pump and its head or discharge were studied through a frequency response analysis to address the discretization issue of existing computational approaches. The transfer functions for the head and discharge between the upstream and downstream pumps were derived for a reservoir-pipeline-pump-pipeline-valve system by employing the quadratic head versus discharge curve for a centrifugal pump and a similarity law. The computed time series of the head for a water hammer induced by closing the end valve was consistent with those performed using conventional method of characteristics. The feasibility of the transient analysis can be realized through the flexibility for defining system parameters, including the pump location and pipeline length, using developed methods. The distributions of the normalized pressure heads were expressed as functions of the rotational speed of the pump and valve-closure action.