Numerical and Experimental Investigation on Flow Dynamics in a Pipe With an Abrupt Change in Diameter

Abstract

Flow dynamics in a pipe with an abrupt change in diameter was experimentally and numerically analyzed. Two-dimensional stationary Reynolds-averaged Navier–Stokes (RANS) k–ε epsilon model was used to describe the development of axial and radial velocity and turbulent kinetic energy in two cases. The theoretical results were compared with experimental findings gained in a transparent pipe test rig. Particle image velocimetry (PIV) technique was used to analyze the development of flow in a pipe with complex geometry. The measured and modeled velocities and turbulent kinetic energy were found to be in good agreement. The two-dimensional stationary RANS k–ε model is suitable for the analysis of the flow dynamics in real old rough pipes where the pipe wall build-up leads to changes in the actual diameter of the pipe but the flow can still be considered axially symmetrical.