Technical Training: Turbulence and Roughness for Hydraulic Engineering
Turbulence is a defining factor in every CFD simulation; its existence or absence in a flow drives the modeling approach. These technical training sessions focus on expanding your understanding of turbulence modeling in FLOW-3D HYDRO with six presentations:
Turbulence Modeling Fundamentals: Untangling 1D, 2D, and 3D approaches
Training description: Turbulence is modeled differently across 1D, 2D, and 3D approaches. Understanding those differences is the foundation for selecting and justifying the right turbulence model in FLOW-3D HYDRO.
Learning outcome: How to choose and justify the right turbulence model for your application.
Understanding Grid Dependence Through the Grid Convergence Index
Training description: Meshing is widely recognized as a primary lever of accuracy, and understanding grid dependence is critical for all numeric models. The grid convergence index (GCI) provides a quantitative means for calculating grid dependence and solution uncertainty for each output of interest.
Learning outcome: How to calculate the GCI and what it means.
Why y+ is Different for Civil Engineering Applications
Training description: Throughout the CFD community, modelers discuss and report y+ for their models. When do model objectives allow you to depart from traditional y+ recommendations?
Learning outcome: What y+ is, the commonly accepted required values for y+, when those values depart from traditional recommendations, and how to explain it in a report.
Physical Roughness Modeling from Grains to Boulders
Training description: The interpretation of roughness is different in 1D, 2D and 3D models. In a 1D model, energy loss coefficients are often accumulated into a single roughness coefficient, such as Manning’s n. In 2D and 3D models more energy losses are resolved, changing the interpretation of roughness and other loss coefficients. In 3D models, the representation of roughness varies between sub-grid scale and explicit resolution, with different limitations present for each approach.
Learning outcome: Understand the difference between resolved and unresolved energy losses and how they affect the model.
Large Eddy Simulation: Is It Better than RANS?
Training description: Large eddy simulation (LES) is an available turbulence modeling option, but how is it different from Reynolds-Averaged Navier-Stokes (RANS) models and how is it used properly?
Learning outcome: The benefits and limitations of using the LES turbulence model, including meshing requirements, and when using LES is worth the additional computational cost.
2D/3D Hybrid Modeling, Guidance and Best Practice
Training description: Combining 2D and 3D simulations offers an opportunity to save computational resources by modeling only those portions of the domain in 3D where that capability is needed. Understanding the interface treatment between the two types of modeling is important to understanding best practices for hybrid model simulations.
Learning outcome: When to apply hybrid modeling, how information is transferred between 2D and 3D mesh blocks, and where to place hybrid transitions.