|
|
# scaling
|
|
|
|
|
|
Convert quantities between model and prototype scale using Froude and Reynoolds similitude.
|
|
|
|
|
|
## Installation
|
|
|
|
|
|
```
|
|
|
pip install git+http://git.wrl.unsw.edu.au:3000/danh/scaling.git
|
|
|
```
|
|
|
|
|
|
## Usage
|
|
|
|
|
|
```python
|
|
|
>>> from scaling import Froude
|
|
|
>>> froude = FroudeConverter()
|
|
|
|
|
|
>>> # Convert model value of 200 mm to prototype value (m) with scale of 10
|
|
|
>>> froude.model_to_proto(200, length_scale=10, input_unit='mm', target_unit='m')
|
|
|
2.0
|
|
|
|
|
|
>>> # Get Froude scaling exponent for quantities of time
|
|
|
>>> froude.scaling_exponent('s')
|
|
|
0.5
|
|
|
|
|
|
>>> # Get length, mass and time dimensions for quantities of energy
|
|
|
>>> froude.dimensions('kJ')
|
|
|
'L^2 M^1 T^-2'
|
|
|
```
|
|
|
|
|
|
Dataframes are also accepted, and specific units can be specified for the values in the index.
|
|
|
|
|
|
```python
|
|
|
>>> T = 2
|
|
|
>>> H = 100
|
|
|
|
|
|
>>> # Generate regular waves with height=100mm, and period=2s
|
|
|
>>> t = np.arange(0, 10.1, 0.1)
|
|
|
>>> eta = 0.5 * H * np.sin(t * 2 * np.pi / T)
|
|
|
|
|
|
>>> df_model = pd.DataFrame(index=t, data=eta)
|
|
|
>>> df_model.columns = ['$\eta$ (mm)']
|
|
|
>>> df_model.index.name = 'Time (s)'
|
|
|
|
|
|
>>> df_model.plot()
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
```python
|
|
|
>>> # Convert to prototype dimensions, with length scale=25
|
|
|
df_proto = froude.model_to_proto(
|
|
|
df_model,
|
|
|
length_scale=25,
|
|
|
input_unit='mm',
|
|
|
target_unit='m',
|
|
|
index_input_unit='s',
|
|
|
index_target_unit='s')
|
|
|
|
|
|
df_proto.columns = ['$\eta$ (m)']
|
|
|
df_proto.plot()
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
`scaling` uses `pint` for unit and dimension conversions. `pint` is able to interpret a wide range of different input units.
|
|
|
|
|
|
```python
|
|
|
>>> # Convert water head model value (mm) to prototype pressure value (kPa)
|
|
|
>>> froude.model_to_proto(10, length_scale=100, 'mm.H20', 'kPa')
|
|
|
9.80665
|
|
|
|
|
|
>>> # Demonstrate different ways of specifying units of Newtons
|
|
|
>>> froude.dimensions('N')
|
|
|
'L^1 M^1 T^-2'
|
|
|
>>> froude.dimensions('newton')
|
|
|
'L^1 M^1 T^-2'
|
|
|
>>> froude.dimensions('kg.m/s/s')
|
|
|
'L^1 M^1 T^-2'
|
|
|
>>> froude.dimensions('kilogram.metre/second^2')
|
|
|
'L^1 M^1 T^-2'
|
|
|
```
|