Hydraulic Transients

Abstract

The flow regime in hydraulic plants is often unsteady with frequent variations of flow rate due to opening/closing valves, pumps, turbines. The inertia of the fluid must be included in computations, and the induced variations of pressure can be so high to excite the fluid compressibility. According to the dominant aspect, a broad classification of unsteady phenomena is in (i) mass oscillations and (ii) elastic oscillations, although both phenomena are generally present at the same time, but with well different time scales.