# Postprocessing NREL5MW AMR-Wind RIGID results

**Contents**

- [OpenFAST turbine results](#openfast-turbine-results)
- [OpenFAST blade loading profiles](#openfast-blade-loading-profiles)
- [Contour plots](#contour-plots)
- [Averaged wake profiles](#averaged-wake-profiles)

The following document describes the post-processing procedures for the AMR-Wind turbine simulation.  

**Note**: In many of the python scripts and Jupyter notebooks provided, the path to the [AMR-Wind front end](https://github.com/Exawind/amr-wind-frontend) library must be provided.  If necessary, download the library and edit the lines in the python code which define `amrwindfedirs` to include any locations of that library.
```python
# Add any possible locations of amr-wind-frontend here
amrwindfedirs = ['/projects/wind_uq/lcheung/amrwind-frontend/',
                 '/ccs/proj/cfd162/lcheung/amrwind-frontend/']
import sys, os, shutil, io
for x in amrwindfedirs: sys.path.insert(1, x)
```

## OpenFAST turbine results

- Jupyter notebook: [OpenFAST_v40_Results.ipynb](OpenFAST_v40_Results.ipynb)
- python script: [OpenFAST_v40_Results.py](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/postprocessing/OpenFAST_v40_Results.py)

These scripts extract out specific performance quantities from the OpenFAST output files and creates a time history of quantities to compare, as well as averaging them over a specific time period.  To use the scripts and notebooks above, change the `RUNDIR` variable in the `replacedict` definition:

```python
replacedict={'RUNDIR':'/gpfs/lcheung/HFM/exawind-benchmarks/NREL5MW_ALM_RIGID_OFv402/',
             'RESULTSDIR':'../results/OpenFAST_v402_out',
            }
```

Inside the `yamlstring` variable, also double-check the `trange` variable to make sure the averaging time is correct:

```yaml
trange: &trange [300, 900]   # Note: add 15,000 sec to get AMR-Wind time
```

Then execute and run the notebook/script and it will extract the results.
```bash
$ python OpenFAST_v40_Results.py
```

The outputs of the script are contained in two CSV files:
- [NREL5MW.csv](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/results/OpenFAST_v402_out/NREL5MW.csv): A time history of turbine parameters such as blade pitch, rotor speed, rotor thrust, rotor torque, and generator power.
- [NREL5MW_mean.csv](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/results/OpenFAST_v402_out/NREL5MW_mean.csv): The time average of the turbine properties over the time period defined by `trange`.

 Plots of the quantities from `NREL5MW.csv` are also generated in the [images](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/results/images) directory, look for the `OpenFAST_T0_*.png` files.

## OpenFAST blade loading profiles

- Jupyter notebook: [OpenFAST_SectionalLoading.ipynb](OpenFAST_SectionalLoading.ipynb)
- python script: [OpenFAST_SectionalLoading.py](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/postprocessing/OpenFAST_SectionalLoading.py)

Similar to the scripts which extract the time-history of the turbine quantities above, the notebook and python script above extract the blade loading profiles from the OpenFAST output file.  These include the radial distributions of angle of attack, lift/drag coefficients, and streamwise/tangential blade forces.

In the notebook and python script, edit the locations of the files in these variables
```python
rundir = '/gpfs/lcheung/HFM/exawind-benchmarks/NREL5MW_ALM_RIGID_OFv402/'
bladefile = rundir+'/T0_NREL5MW_v402_RIGID/openfast/5MW_Baseline/NRELOffshrBsline5MW_AeroDyn_blade.dat'
```

and define the list of variables to extract here: 
```python
suffixkeys = ['Alpha', 'Phi', 'Cl','Cd', 'Fx','Fy']
```

The time range to average the data is defined in `trange`:

```yaml
trange: &trange [300, 900]   # Note: add 15,000 sec to get AMR-Wind time
```

The raw output will be stored in the file [NREL5MW_SECLOADS_mean_rpts.csv](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/results/OpenFAST_v402_out/NREL5MW_SECLOADS_mean_rpts.csv).  Plots of the blade loading are also generated in the [images](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/results/images) directory, in the files:

- OpenFAST_T0_AOA.png
- OpenFAST_T0_ClCd.png
- OpenFAST_T0_FxFy.png

## Contour plots

- Jupyter notebook: [InstantaneousAvgPlanes.ipynb](InstantaneousAvgPlanes.ipynb)
- python script: [InstantaneousAvgPlanes.py](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/postprocessing/InstantaneousAvgPlanes.py)

Images of the domain and the flow-field around the turbine are generated using the Jupyter notebook and python script above.  The notebook and script will extract hub-height and streamwise slices from the sampling planes that were generated from AMR-Wind.  They will also perform a time-average of the hub-height plane through the entire domain for a quick visualization.

To use the postprocessing script and notebook, edit the `RUNDIR` to reflect the location of the AMR-Wind run.
```python
replacedict={'RUNDIR':'/gpfs/lcheung/HFM/exawind-benchmarks/NREL5MW_ALM_RIGID_OFv402/',
            }
```

Also, if necessary, change the time period specified in `trange`.  Currently it is set to do a 10-min average of the simulation after the initial transient period.

```yaml
trange: &trange [15300, 15900]
```

After running the notebook, it should generate the following images from the domain:

- [XYdomain_AVG_15300_15900.png](../results/images/XYdomain_AVG_15300_15900.png)
- [XYdomain_INST_15300.png](../results/images/XYdomain_INST_15300.png)
- [XYdomain_INST_15900.png](../results/images/XYdomain_INST_15900.png)
- [turbineHH_INST_15300.png](../results/images/turbineHH_INST_15300.png)
- [turbineHH_INST_15900.png](../results/images/turbineHH_INST_15900.png)
- [turbineSW_INST_15300.png](../results/images/turbineSW_INST_15300.png)
- [turbineSW_INST_15900.png](../results/images/turbineSW_INST_15900.png)

## Averaged wake profiles

- Jupyter notebook: [AVGPlanes.ipynb](AVGPlanes.ipynb)
- python script: [AVGPlanes.py](https://github.com/Exawind/exawind-benchmarks/blob/main/amr-wind/actuator_line/NREL5MW_ALM_BD/postprocessing/AVGPlanes.py)

These postprocesssing notebook and python script will extract hub-height and streamwise wake profiles from the sampling planes generated by AMR-Wind.  

The time range to average the profiles is defined by the `trange` variable.  Currently it is set to compute a 10 minute average after an initial 5 minute transient period: 

```yaml
trange: &trange [15300, 15900]
```

The locations of the hub-height wake profiles are defined by the `interpXY` user-defined function.  Currently it creates profiles at x/D = 1,2,3, ... 9 downstream, and from -2 <= y/D <= 2 laterally with 1 meter resolution.  The results are stored in the `results/HHProfiles_300_900` subdirectory.
```python
def interpXY(xD):
    """
    Interpolate on the XY hub-height plane plane 
    """
    D  = 126.0
    x0 = D*4.0
    y0 = D*2.0
    z0 = 90.0
    x = D*xD
    ptlist = [[x+x0, y+y0] for y in np.linspace(-D*2, D*2, int(D*4+1))]
    return ptlist

for x in [1,2,3,4,5,6,7,8,9,10]:
    setattr(ppeng, 'interpXY'+repr(x), partial(interpXY, x))
```

The locations of the streamwise profiles are defined by the `interpXZ` user-defined function.  Currently it creates profiles at x/D = 1,2,3, ... 10 downstream, and from 0 < z/D <= 2 with 1 meter resolution.  The results are stored in the `results/XZProfiles_300_900` subdirectory.
```python
def interpXZ(xD):
    """
    Interpolate on the XZ streamwise plane 
    """
    D  = 126.0
    x0 = D*4.0
    y0 = 0
    x = D*xD
    ptlist = [[x+x0, y+y0] for y in np.linspace(1, D*2, int(D*2))]
    return ptlist

for x in [1,2,3,4,5,6,7,8,9,10]:
    setattr(ppeng, 'interpXZ'+repr(x), partial(interpXZ, x))
```

Averaged contour plots for both the hub-height and the streamwise cases are also created and saved:

- [turbineHH_AVG_300_900.png](../results/images/turbineHH_AVG_300_900.png)
- [turbineSW_AVG_300_900.png](../results/images/turbineSW_AVG_300_900.png)