Applied Turbulence Modeling - Lecture 3
28 October 2026, Sebastian Spring
The RANS Equations
More on L2 slides 28 onwards \
| Viscous stress | Reynolds stress |
|---|---|
| diffusive momentum flux due to molecular motion | averaged convecitve momentum flix due to velocity fluctuations |
| a property of the fluid | a property of the flow, varies in space |
| closed by a constitutive law | unknown - requires a turbulence model |
Exact Transport Equations
- at high reynolds numbers, dissipation via turbulence dominates - except very close to walls
- $\varepsilon$ used in all modelss is the pseurdo-dissipation; it equals the true dissipation in homogeneous turbulence
- Notation: $\phi$ = viscous heat source in the energy equation $\varepsilon$ = turbulent dissipation rate
Good diagram on L3 Slide 23
Information about the Exercises
- not mandatory - fill out ilias survey if interested
- five exercises
- introduction to openfoam
- introduction to paraview
- calculation methodology
- your task: choose one of five projects to do in teams of up to four students
- work on that for a few weeks, then present findings