Hydraulics & Waterways
394522 - Numerical Investigation of a Retrofitting Method for Minimizing Violent Geysers in Sewer Systems
Monday, June 4
10:30 AM - 12:00 PM
Location: Regency Room
Minh K. Phan, Houston, Texas – University of Houston; Arturo S. Leon, Houston, Texas – University of Houston
Recently, there have been a number of numerical and experimental studies which provided a better understanding of the processes leading to formation of violent geysers in sewer systems. These studies demonstrated the significance of a sequence of interactions between liquid and gas phases as well as the subsequent changes in the flow regime. In this study, a retrofitting method is proposed and validated based on these new insights. This method is based on utilizing an inclined conduit that connects the near-horizontal tunnel, at each side of the dropshaft, with the dropshaft at a point above the expected initial water level in the shaft. The inclined shafts release the approaching air pockets in a non-dynamic way, in contrast to the configuration with the dropshaft only. First, a numerical model which is configured in OpenFOAM is validated using our laboratory experiments of violent geysers with no retrofitting. Then, suitability of the proposed method has been verified through new laboratory experiments. Additionally, a series of numerical simulations has been performed for assessing and optimizing the design parameters, which include the diameter of the inclined conduit, vertical distance between the crown of the horizontal pipe and its connection to the inclined conduit, as well as the angle between the horizontal tunnel and the inclined conduit. The numerical and experimental results demonstrate the suitability of the proposed method for minimizing geysering events in sewer systems.