CFD Analysis of Outlet Energy Dissipation Structure at the Big Sand Wash Reservoir — Upalco, Utah

Rapid advances in state-of-the-art computational fluid dynamics (CFD) analyses are being made in simulating multi-phase flow fields, particularly where fluid-structural member interactions, air-water interfaces (free surfaces), and bubbly mixtures are involved. Coupled equations link the Navier-Stokes equations of fluid motion with structural deformation equations to simulate both fluid and structural response to either steady-state or transient boundary conditions. Consequently, defensible calculations that are based on the best formulas used in engineering practice can be utilized for comprehensive hydraulic structural design. Problems associated with frothy free surfaces and bubble formation can now benefit from CFD implementation of research results regarding two-phase, air-water flow. A case study which illustrates the benefits of CFD analyses to guide difficult hydraulic structure designs is presented. The case study consists of flow through fixed cone valves (sometimes called Howell-Bunger or ring jet valves) into a stilling basin. These turbulent discharge conditions cause undesirable spray. CFD analyses were used to evaluate performance improvement options and assist with the final design alternative.