Using Numerical Modeling to Predict the Energy Dissipation Characteristics and Dissolved Oxygen Content Downstream of Energy Dissipation structures

Hydraulic jump formation is the primary driver to reducing kinetic energy downstream of spillways, sluice gates, stormwater culvers, and irrigation canals. In practice, engineers use energy dissipaters to accelerate the formation of hydraulic jumps, increasing kinetic energy dissipation. Both analytical solutions and lab studies are used to design and optimize energy dissipaters, however using both these methods alone can have drawbacks. Analytical solutions tend to be a good first step but are conservative and only work in the limited range of flow rates that were used to develop the equations. Lab studies, while more thorough, can often be expensive and time consuming, especially when multiple design iterations are necessary.
A good alternative is to supplement these methods with computational fluid dynamics (CFD) analyses. CFD can be used as a numerical test bed for that allows for great flexibility to evaluate unique and complex designs that may not be suitable with standard analysis methods. Despite these capabilities, it is important for both hydraulic models and stakeholders to understand the advantages and disadvantages of CFD for these applications.
In this paper, we will explore these capabilities and limitations through a CFD validation by comparing simulations results with detailed measurements of energy dissipation at a hydraulic control structure. We will look at important aspects of the CFD model setup and how they affect accuracy relative to measured results, and the implications for those considering using CFD for these applications.