Steel-Fab, Inc. (Steel-Fab) required hydraulic engineering support to complete a three-dimensional (3D) computational fluid dynamics (CFD) hydraulic modeling analysis of a proposed jet gate that was being designed for the City of Columbia, Ohio’s Hoover Dam. The gate would be located at the dam’s base, upstream end of an existing tunnel. The purpose of the 3D modeling study was to determine if an existing air vent in the tunnel could supply enough air to avoid low pressures from occurring in the tunnel when the gate was open. Steel-Fab could avoid including a new vent on the jet gate valve assembly if the existing vent was adequate.
Kleinschmidt used the 3D CFD software FLOW-3D HYDRO (FLOW-3D) to complete the analysis. The model domain extended from upstream of the jet gate orifice to downstream from the end of a new aeration structure located at the downstream end of the 70-foot-long tunnel. Kleinschmidt used FLOW-3D to model 1-fluid (e.g., water) and 2-fluid (e.g., water and air) simulations to understand the sensitivity of the results to different types of fluid physics.
Our team evaluated three cases to test air demand requirements within the tunnel: 1-fluid simulation with the existing air vent, 2-fluid simulation with the existing air vent, and 1-fluid simulation with existing and new jet gate vents. Based on the modeling results, Kleinschmidt provided recommendations for installing and placing a new air vent to reduce the likelihood of cavitation, reduce potentially problematic whistling sounds within the vents, and provide operational recommendations to minimize or eliminate potentially problematic pressure gradients during gate opening.
Kleinschmidt’s 3D CFD modeling provided Steel-Fab with a level of certainty that adding a new vent was justified to prevent damage to the gate or tunnel. The complex nature of the water and air flow and interactions necessitated the CFD modeling, which provided more detail at a lower cost than physical modeling would have achieved.
Regional Vice President
Chris Goodwin, P.E.
“I was attracted to Kleinschmidt by the culture and focus of the company on water resources and renewable energy. The culture has lived up to the expectations and I am excited to be part of a team all rowing in the same direction” Chris Goodwin has over 35 years of water resources-specific experience and specializes...