def calc_perf(theta_0=360,
plot=False,
verbose=True,
inertial=False,
export_csv=True):
t, torque, drag = foampy.load_all_torque_drag()
_t, theta, omega = foampy.load_theta_omega(t_interp=t)
reached_theta_0 = True
if theta.max() < theta_0:
theta_0 = 1
reached_theta_0 = False
# Compute tip speed ratio
tsr = omega * R / U_infty
# Compute mean TSR
meantsr = np.mean(tsr[theta >= theta_0])
if inertial:
inertia = 3 # guess from SolidWorks model
inertial_torque = inertia * fdiff.second_order_diff(omega, t)
torque -= inertial_torque
# Compute power coefficient
power = torque * omega
cp = power / (0.5 * rho * area * U_infty**3)
meancp = np.mean(cp[theta >= theta_0])
# Compute drag coefficient
cd = drag / (0.5 * rho * area * U_infty**2)
meancd = np.mean(cd[theta >= theta_0])
if export_csv:
df = pd.DataFrame()
df["theta_deg"] = theta
df["tsr"] = tsr
df["cp"] = cp
df["cd"] = cd
df.to_csv("processed/perf.csv", index=False)
if verbose:
print("Performance from {:.1f}--{:.1f} degrees:".format(
theta_0, theta.max()))
print("Mean TSR = {:.3f}".format(meantsr))
print("Mean C_P = {:.3f}".format(meancp))
print("Mean C_D = {:.3f}".format(meancd))
if plot:
plt.close('all')
plt.plot(theta[5:], cp[5:])
plt.title(r"$\lambda = %1.1f$" % meantsr)
plt.xlabel(r"$\theta$ (degrees)")
plt.ylabel(r"$C_P$")
#plt.ylim((0, 1.0))
plt.tight_layout()
plt.show()
if reached_theta_0:
return {"C_P": meancp, "C_D": meancd, "TSR": meantsr}
else:
return {"C_P": "nan", "C_D": "nan", "TSR": "nan"}
def test_gen_dynmeshdict():
os.chdir("test")
u = 1
r = 1
meantsr = 1
foampy.gen_dynmeshdict(u, r, meantsr, npoints=10, rpm_fluc=0)
t, theta, omega = foampy.load_theta_omega()
assert t.min() == 0
assert t.max() == 0.5
assert len(omega) == 10
assert np.mean(omega*r/u) == meantsr
os.chdir("../")
os.system("git checkout test/constant/dynamicMeshDict")
def calc_perf(theta_0=360, plot=False, verbose=True, inertial=False):
t, torque, drag = foampy.load_all_torque_drag()
_t, theta, omega = foampy.load_theta_omega(t_interp=t)
reached_theta_0 = True
if theta.max() < theta_0:
theta_0 = 1
reached_theta_0 = False
# Compute tip speed ratio
tsr = omega*R/U_infty
# Compute mean TSR
meantsr = np.mean(tsr[theta >= theta_0])
if inertial:
inertia = 3 # guess from SolidWorks model
inertial_torque = inertia*fdiff.second_order_diff(omega, t)
torque -= inertial_torque
# Compute power coefficient
power = torque*omega
cp = power/(0.5*rho*area*U_infty**3)
meancp = np.mean(cp[theta >= theta_0])
# Compute drag coefficient
cd = drag/(0.5*rho*area*U_infty**2)
meancd = np.mean(cd[theta >= theta_0])
if verbose:
print("Performance from {:.1f}--{:.1f} degrees:".format(theta_0,
theta.max()))
print("Mean TSR = {:.3f}".format(meantsr))
print("Mean C_P = {:.3f}".format(meancp))
print("Mean C_D = {:.3f}".format(meancd))
if plot:
plt.close('all')
plt.plot(theta[5:], cp[5:])
plt.title(r"$\lambda = %1.1f$" %meantsr)
plt.xlabel(r"$\theta$ (degrees)")
plt.ylabel(r"$C_P$")
#plt.ylim((0, 1.0))
plt.tight_layout()
plt.show()
if reached_theta_0:
return {"C_P" : meancp,
"C_D" : meancd,
"TSR" : meantsr}
else:
return {"C_P" : "nan",
"C_D" : "nan",
"TSR" : "nan"}
def calc_blade_vel():
"""Calculates blade angle of attack and relative velocity time series."""
# Load sampled data
data = load_set(name="bladePath", quantity="U")
times = data["time"]
# Load turbine azimuthal angle time series
_t, theta_blade, omega = foampy.load_theta_omega(t_interp=times)
theta_turbine = theta_blade*1
theta_blade = theta_blade.round(decimals=0) % 360
theta_probe = theta_blade + 4
theta_blade_rad = theta_blade/180*np.pi
rel_vel = []
alpha = []
rel_vel_geom = []
alpha_geom = []
# Calculate an array of thetas that correspond to each sampled point
for i, t in enumerate(times):
x = data[t]["x"]
y = data[t]["y"]
u = data[t]["u"]
v = data[t]["v"]
theta = np.round(np.arctan2(-x, y)*180/np.pi, decimals=0)
theta = [(360 + th) % 360 for th in theta]
blade_vel_mag = omega[i]*R
blade_vel_x = blade_vel_mag*np.cos(theta_blade_rad[i])
blade_vel_y = blade_vel_mag*np.sin(theta_blade_rad[i])
u_geom = 1.0
rel_vel_mag_geom = np.sqrt((blade_vel_x + u_geom)**2 + blade_vel_y**2)
rel_vel_geom.append(rel_vel_mag_geom)
rel_vel_x_geom = u_geom + blade_vel_x
rel_vel_y_geom = blade_vel_y
relvel_dot_bladevel_geom = (blade_vel_x*rel_vel_x_geom + blade_vel_y*rel_vel_y_geom)
_alpha = np.arccos(relvel_dot_bladevel_geom/(rel_vel_mag_geom*blade_vel_mag))
alpha_geom.append(_alpha*180/np.pi)
try:
ivel = theta.index(theta_probe[i])
ui = u[ivel]
vi = v[ivel]
rel_vel_mag = np.sqrt((blade_vel_x + ui)**2 + (blade_vel_y + vi)**2)
rel_vel.append(rel_vel_mag)
rel_vel_x = ui + blade_vel_x
rel_vel_y = vi + blade_vel_y
relvel_dot_bladevel = (blade_vel_x*rel_vel_x + blade_vel_y*rel_vel_y)
_alpha = np.arccos(relvel_dot_bladevel/(rel_vel_mag*blade_vel_mag))
alpha.append(_alpha*180/np.pi)
except ValueError:
rel_vel.append(np.nan)
alpha.append(np.nan)
rel_vel = np.array(rel_vel)
alpha = np.array(alpha)
alpha[theta_blade > 180] = -alpha[theta_blade > 180]
rel_vel_geom = np.array(rel_vel_geom)
alpha_geom = np.array(alpha_geom)
alpha_geom[theta_blade > 180] = -alpha_geom[theta_blade > 180]
theta_0 = 720
alpha = alpha[theta_turbine > theta_0]
rel_vel = rel_vel[theta_turbine > theta_0]
alpha_geom = alpha_geom[theta_turbine > theta_0]
rel_vel_geom = rel_vel_geom[theta_turbine > theta_0]
theta_turbine = theta_turbine[theta_turbine > theta_0]
plt.figure(figsize=(8,3))
plt.subplot(1, 2, 1)
plt.plot(theta_turbine, alpha, "--ok")
plt.plot(theta_turbine, alpha_geom)
plt.xlabel("Azimuthal angle (degrees)")
plt.ylabel("Angle of attack (degrees)")
plt.subplot(1, 2, 2)
plt.plot(theta_turbine, rel_vel, "--ok")
plt.plot(theta_turbine, rel_vel_geom)
plt.xlabel("Azimuthal angle (degrees)")
plt.ylabel("Relative velocity (m/s)")
plt.tight_layout()
plt.show()
def calc_blade_vel():
"""Calculates blade angle of attack and relative velocity time series."""
# Load sampled data
data = load_set(name="bladePath", quantity="U")
times = data["time"]
# Load turbine azimuthal angle time series
_t, theta_blade, omega = foampy.load_theta_omega(t_interp=times)
theta_turbine = theta_blade * 1
theta_blade = theta_blade.round(decimals=0) % 360
theta_probe = theta_blade + 4
theta_blade_rad = theta_blade / 180 * np.pi
rel_vel = []
alpha = []
rel_vel_geom = []
alpha_geom = []
# Calculate an array of thetas that correspond to each sampled point
for i, t in enumerate(times):
x = data[t]["x"]
y = data[t]["y"]
u = data[t]["u"]
v = data[t]["v"]
theta = np.round(np.arctan2(-x, y) * 180 / np.pi, decimals=0)
theta = [(360 + th) % 360 for th in theta]
blade_vel_mag = omega[i] * R
blade_vel_x = blade_vel_mag * np.cos(theta_blade_rad[i])
blade_vel_y = blade_vel_mag * np.sin(theta_blade_rad[i])
u_geom = 1.0
rel_vel_mag_geom = np.sqrt((blade_vel_x + u_geom)**2 + blade_vel_y**2)
rel_vel_geom.append(rel_vel_mag_geom)
rel_vel_x_geom = u_geom + blade_vel_x
rel_vel_y_geom = blade_vel_y
relvel_dot_bladevel_geom = (blade_vel_x * rel_vel_x_geom +
blade_vel_y * rel_vel_y_geom)
_alpha = np.arccos(relvel_dot_bladevel_geom /
(rel_vel_mag_geom * blade_vel_mag))
alpha_geom.append(_alpha * 180 / np.pi)
try:
ivel = theta.index(theta_probe[i])
ui = u[ivel]
vi = v[ivel]
rel_vel_mag = np.sqrt((blade_vel_x + ui)**2 +
(blade_vel_y + vi)**2)
rel_vel.append(rel_vel_mag)
rel_vel_x = ui + blade_vel_x
rel_vel_y = vi + blade_vel_y
relvel_dot_bladevel = (blade_vel_x * rel_vel_x +
blade_vel_y * rel_vel_y)
_alpha = np.arccos(relvel_dot_bladevel /
(rel_vel_mag * blade_vel_mag))
alpha.append(_alpha * 180 / np.pi)
except ValueError:
rel_vel.append(np.nan)
alpha.append(np.nan)
rel_vel = np.array(rel_vel)
alpha = np.array(alpha)
alpha[theta_blade > 180] = -alpha[theta_blade > 180]
rel_vel_geom = np.array(rel_vel_geom)
alpha_geom = np.array(alpha_geom)
alpha_geom[theta_blade > 180] = -alpha_geom[theta_blade > 180]
theta_0 = 720
alpha = alpha[theta_turbine > theta_0]
rel_vel = rel_vel[theta_turbine > theta_0]
alpha_geom = alpha_geom[theta_turbine > theta_0]
rel_vel_geom = rel_vel_geom[theta_turbine > theta_0]
theta_turbine = theta_turbine[theta_turbine > theta_0]
plt.figure(figsize=(8, 3))
plt.subplot(1, 2, 1)
plt.plot(theta_turbine, alpha, "--ok")
plt.plot(theta_turbine, alpha_geom)
plt.xlabel("Azimuthal angle (degrees)")
plt.ylabel("Angle of attack (degrees)")
plt.subplot(1, 2, 2)
plt.plot(theta_turbine, rel_vel, "--ok")
plt.plot(theta_turbine, rel_vel_geom)
plt.xlabel("Azimuthal angle (degrees)")
plt.ylabel("Relative velocity (m/s)")
plt.tight_layout()
plt.show()
