28_extract_wind_speed_at_points.py

# Copyright 2023 NREL

# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.

# See https://floris.readthedocs.io for documentation


import matplotlib.pyplot as plt
import numpy as np

from floris.tools import FlorisInterface


"""
This example demonstrates the use of the sample_flow_at_points method of
FlorisInterface. sample_flow_at_points extracts the wind speed
information at user-specified locations in the flow.

Specifically, this example returns the wind speed at a single x, y
location and four different heights over a sweep of wind directions.
This mimics the wind speed measurements of a met mast across all
wind directions (at a fixed free stream wind speed).

Try different values for met_mast_option to vary the location of the
met mast within the two-turbine farm.
"""

# User options
# FLORIS model to use (limited to Gauss/GCH, Jensen, and empirical Gauss)
floris_model = "gch" # Try "gch", "jensen", "emgauss"
# Option to try different met mast locations
met_mast_option = 0 # Try 0, 1, 2, 3

# Instantiate FLORIS model
fi = FlorisInterface("inputs/"+floris_model+".yaml")

# Set up a two-turbine farm
D = 126
fi.reinitialize(layout_x=[0, 3 * D], layout_y=[0, 3 * D])

fig, ax = plt.subplots(1,2)
fig.set_size_inches(10,4)
ax[0].scatter(fi.layout_x, fi.layout_y, color="black", label="Turbine")

# Set the wind direction to run 360 degrees
wd_array = np.arange(0, 360, 1)
fi.reinitialize(wind_directions=wd_array)

# Simulate a met mast in between the turbines
if met_mast_option == 0:
    points_x = 4 * [3*D]
    points_y = 4 * [0]
elif met_mast_option == 1:
    points_x = 4 * [200.0]
    points_y = 4 * [200.0]
elif met_mast_option == 2:
    points_x = 4 * [20.0]
    points_y = 4 * [20.0]
elif met_mast_option == 3:
    points_x = 4 * [305.0]
    points_y = 4 * [158.0]

points_z = [30, 90, 150, 250]

# Collect the points
u_at_points = fi.sample_flow_at_points(points_x, points_y, points_z)

ax[0].scatter(points_x, points_y, color="red", marker="x", label="Met mast")
ax[0].grid()
ax[0].set_xlabel("x [m]")
ax[0].set_ylabel("y [m]")
ax[0].legend()

# Plot the velocities
for z_idx, z in enumerate(points_z):
    ax[1].plot(wd_array, u_at_points[:, :, z_idx].flatten(), label=f'Speed at z={z} m')
ax[1].grid()
ax[1].legend()
ax[1].set_xlabel('Wind Direction (deg)')
ax[1].set_ylabel('Wind Speed (m/s)')

plt.show()