Theoretical and Experimental Investigation of Hydraulic Jumps in Closed Conduits

Abstract

This article examines the conditions for the development of hydraulic jumps in pipelines, the types of jumps, and the locations where they typically occur. A theoretical method for determining the relationship between conjugate depths is presented, along with its influence on the hydraulic regime of pipeline operation. In gravity pipelines, free-surface, pressurized, and mixed flow regimes may appear. The transition from pressurized to free-surface flow is smooth, whereas the reverse transition involves a surface discontinuity similar to a hydraulic jump in open channels. For a given discharge, the jump location depends solely on flow rate; as the flow increases, the jump shifts upstream. The behavior of hydraulic jumps and resulting flow choking in circular pipes remains insufficiently studied, though theory and experiments show encouraging agreement. This analysis is important for multipurpose water conduits, where free-flow sections are preferable for energy applications.