Experimental Study of the Effect of Inserts on Flow-Induced Pulsations at T-joints in Ducts

Abstract

The goal of this study is to investigate the e ect of inserts at T-joints on Flow-Induced Pulsations. In gas transport pipe systems, Flow-Induced Pulsations can for example occur when a grazing ow is grazing on a closed side branch. This kind of situations is typically found in metering or mixing stations in natural gas transport and distribution networks, and at the connection of anti-surge lines in compressors. These pulsations can induce large forces on the piping, in some cases resulting in pipe failures. The geometry of the Tee connection is critical for the amplitude of the source. It has for example been demonstrated that a connection with rounded edges can produce larger ow-induced pulsations than a connection with sharp edges. When this problem is foreseen at the design phase, it is possible to search for remedies, for example by detuning the acoustical resonator by modifying the pipe routing and the pipe length. In some cases, it is also possible to reduce the pulsation sources. Indeed, Tee connections in gas transport systems are sometimes equipped with gratings, grids, or with so-called scrapper guides, which are meant to guide the cleaning device (pig) towards the export piping. The motivation of this study was to investigate the e ect of various inserts at Tee connections on the pulsation, so that the best choice can be made to avoid or reduce pulsations. The inserts and con gurations have been chosen such that the e ect of the inserts on the source amplitude can be separated from the e ect on the acoustic damping.