Turbulence Modeling
This module focused on the complexities of turbulence and the strategies available in CFD to capture its behavior. Starting with the foundations of RANS–Boussinesq models, the course progressively explored more advanced formulations, Reynolds Stress Models, and approaches to near-wall modeling. Transition mechanisms between laminar and turbulent flow were studied, before moving to scale-resolving simulations such as LES and hybrid RANS/SRS methods
The homework assignments built steadily on these concepts.
Homework 1–2: Reviewed basic turbulence descriptions and applied improved RANS closures to canonical flows, including anisotropy effects.
Homework 3: Examined near-wall treatments and compared different wall functions, showing how mesh resolution and model choice influence velocity profiles and wall shear stress predictions.
Homework 4: Focused on laminar–turbulent transition, simulating flat-plate boundary layers and validating transition onset against theory.
Homework 5: Introduced scale-resolving simulations, running LES on turbulent channel flows and highlighting the differences between resolved eddies and modeled turbulence.
Final Homework: Combined the tools into a large-scale application — simulating the unsteady wind flow around a tall cuboid building. A wall-modeled LES (WMLES S-Omega) was used to capture vortex shedding, wake recirculation, and fluctuating lateral forces. Mesh design, initialization with RANS, ramp-up strategy, and spectral force analysis were all part of the workflow, tying together the theoretical and practical aspects of turbulence modeling
This module demonstrated how turbulence, often seen as one of the most challenging areas in CFD, can be approached with a hierarchy of models - from robust engineering correlations to highly resolved transient simulations. It was an essential step in learning how to balance accuracy, computational demand, and physical insight in real engineering problems