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BumseokLee committed Oct 7, 2024
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6 changes: 3 additions & 3 deletions nalu-wind/2D_airfoils_Transition/1_NLF1-0416/README.md
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Expand Up @@ -12,6 +12,9 @@ Validation and verification of the transition model were conducted for the NASA
- 2-D strcutred C-type meshes: Tiny, Coarse, Medium, Fine, Extra, Ultra resolutions[^4]
- Turbulence / Transition model: SST-2003 with the 1-eq Gamma transition model with µt/µ=1
- Nalu-Wind version: [6155b17fa6b8914a819a492230c96f7990a97b78](https://github.com/Exawind/nalu-wind/commit/6155b17fa6b8914a819a492230c96f7990a97b78)
- Case run on NREL's Kestrel HPC system using 26 cores / case
- A case with the "Fine" mesh was run on 26 cores of NREL's Kestrel, took approximately 40 minutes to 10,000 iterations, using 4 Picard iterations per time step
- Note that the number of cores per case was not based on the scalability of Nalu-Wind on Kestrel but rather to fit 4 cases onto a single node of Kestrel

## Results: Grid Sensitivity Study

Expand Down Expand Up @@ -39,9 +42,6 @@ Option 2, which applies a constant turbulence intensity, improves grid convergen

Based on the grid sensitivity results, a full sweep of angles of attack was performed using the Fine mesh level. The two figures above compare the lift and drag polar with the experimental measurements[^5]. For the lift, the transition simulation slightly over-predicts the lift coefficient in the linear range of the lift curve, a similar behavior also observed in transition predictions using other transition models and other flow solvers. For the drag polar, the transition simulation predicts lower drag across the range of angles of attack than the fully turbulent simulation, capturing the trend of the experimental data very well.

Each case was run on 26 cores of NREL's Kestrel HPC system and took approximately 40 minutes to 10,000 iterations, using 4 Picard iterations per time step.
Note that the number of cores per case is not based on the scalability of Nalu-Wind but rather to fit 4 cases onto a single node of Kestrel.

## References
[^1]: https://transitionmodeling.larc.nasa.gov/
[^2]: Venkatachari, B. S., et al., "Implementation and Assessment of Menter’s Galilean-Invariant 𝛾
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7 changes: 4 additions & 3 deletions nalu-wind/2D_airfoils_Transition/2_DU00-W-212/README.md
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Expand Up @@ -9,15 +9,16 @@ Validation of the transition model is conducted for the DU00-W-212 airfoil airfo
- Test airfoil: DU00-W-212 airfoil with a thickness of 21%
- Flow Condition: M=0.1, Re=3million, Tu=0.0864%
- CFD mesh generated using Pointwise
- 2-D structred O-type mesh, with a resolution equivalent to the "Fine" resolution of the AIAA mesh
- 2-D structred O-type mesh, with a resolution equivalent to the "Fine" resolution of the AIAA mesh
- Turbulence / Transition model: SST-2003 with the 1-eq Gamma transition model with µt/µ=1
- Nalu-Wind version: [6155b17fa6b8914a819a492230c96f7990a97b78](https://github.com/Exawind/nalu-wind/commit/6155b17fa6b8914a819a492230c96f7990a97b78)

- Each case was run on 26 cores of NREL's Kestrel, took approximately 40 minutes to 10,000 iterations, using 4 Picard iterations per time step
- Note that the number of cores per case was not based on the scalability of Nalu-Wind on Kestrel but rather to fit 4 cases onto a single node of Kestrel

## Results: Angle of Attack Sweep

### Comparison of the lift, drag, and pitching moment
<img src="figs/du_rey_3M.png" alt="Cf" width="600">
<img src="figs/du_rey_3M.png" alt="Cf" width="1000">

The figure above shows comparisons of the lift, drag, and pitching moment from the experiment, fully turbulent simulations, and transition simulations.

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