def test_2():
"""
This tests the propeller_single_point function using the Fidelity One rotor inflow model.
"""
vehicle = vehicle_setup()
# update the wake method used for each prop
for p in vehicle.networks.battery_propeller.propellers:
p.Wake = Rotor_Wake_Fidelity_One()
analyses = SUAVE.Analyses.Vehicle()
atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976()
atmosphere.features.planet = SUAVE.Analyses.Planets.Planet()
analyses.append(atmosphere)
results = propeller_single_point(vehicle.networks.battery_propeller,
analyses,
pitch=0.,
omega=2200. * Units.rpm,
altitude=5000. * Units.ft,
delta_isa=0.,
speed=10 * Units['m/s'],
plots=True,
print_results=True)
thrust = results.thrust
torque = results.torque
power = results.power
Cp = results.power_coefficient
etap = results.efficiency
thrust_r = 637.9402297052759
torque_r = 129.07946679553763
power_r = 29737.7743383709
Cp_r = 0.03796285858728355
etap_r = 0.21452184768317925
assert (np.abs(thrust - thrust_r) / thrust_r <
1e-6), "Propeller Single Point Regression Failed at Thrust Test"
assert (np.abs(torque - torque_r) / torque_r <
1e-6), "Propeller Single Point Regression Failed at Torque Test"
assert (np.abs(power - power_r) / power_r <
1e-6), "Propeller Single Point Regression Failed at Power Test"
assert (
np.abs(Cp - Cp_r) / Cp_r < 1e-6
), "Propeller Single Point Regression Failed at Power Coefficient Test"
assert (np.abs(etap - etap_r) / etap_r < 1e-6
), "Propeller Single Point Regression Failed at Efficiency Test"
return
def test_2():
"""
This tests the propeller_single_point function using the helical fixed wake (HFW) + BET model.
"""
HFW = True
vehicle = vehicle_setup()
analyses = SUAVE.Analyses.Vehicle()
atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976()
atmosphere.features.planet = SUAVE.Analyses.Planets.Planet()
analyses.append(atmosphere)
results = propeller_single_point(vehicle.networks.battery_propeller,
analyses,
pitch=0.,
omega=1500. * Units.rpm,
altitude=5000. * Units.ft,
delta_isa=0.,
speed=10 * Units['m/s'],
plots=True,
HFW=HFW,
print_results=True)
thrust = results.thrust
torque = results.torque
power = results.power
Cp = results.power_coefficient
etap = results.efficiency
thrust_r = 2393.728639733924
torque_r = 855.298865633124
power_r = 134350.0316448353
Cp_r = 0.3038702436194616
etap_r = 0.17817105142646564
assert (np.abs(thrust - thrust_r) / thrust_r <
1e-6), "Propeller Single Point Regression Failed at Thrust Test"
assert (np.abs(torque - torque_r) / torque_r <
1e-6), "Propeller Single Point Regression Failed at Torque Test"
assert (np.abs(power - power_r) / power_r <
1e-6), "Propeller Single Point Regression Failed at Power Test"
assert (
np.abs(Cp - Cp_r) / Cp_r < 1e-6
), "Propeller Single Point Regression Failed at Power Coefficient Test"
assert (np.abs(etap - etap_r) / etap_r < 1e-6
), "Propeller Single Point Regression Failed at Efficiency Test"
return
def test_1():
"""
This tests the propeller_single_point function using the BEMT model.
"""
HFW = False
vehicle = vehicle_setup()
analyses = SUAVE.Analyses.Vehicle()
atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976()
atmosphere.features.planet = SUAVE.Analyses.Planets.Planet()
analyses.append(atmosphere)
results = propeller_single_point(vehicle.networks.battery_propeller,
analyses,
pitch=0.,
omega=1500. * Units.rpm,
altitude=5000. * Units.ft,
delta_isa=0.,
speed=10 * Units['m/s'],
plots=True,
HFW=HFW,
print_results=True)
thrust = results.thrust
torque = results.torque
power = results.power
Cp = results.power_coefficient
etap = results.efficiency
thrust_r = 2301.918639576478
torque_r = 827.0007491838651
power_r = 129904.97390746429
Cp_r = 0.29381649996923126
etap_r = 0.17720005086702875
assert (np.abs(thrust - thrust_r) / thrust_r <
1e-6), "Propeller Single Point Regression Failed at Thrust Test"
assert (np.abs(torque - torque_r) / torque_r <
1e-6), "Propeller Single Point Regression Failed at Torque Test"
assert (np.abs(power - power_r) / power_r <
1e-6), "Propeller Single Point Regression Failed at Power Test"
assert (
np.abs(Cp - Cp_r) / Cp_r < 1e-6
), "Propeller Single Point Regression Failed at Power Coefficient Test"
assert (np.abs(etap - etap_r) / etap_r < 1e-6
), "Propeller Single Point Regression Failed at Efficiency Test"
return
def test_1():
"""
This tests the propeller_single_point function using the Fidelity Zero rotor wake inflow model.
"""
vehicle = vehicle_setup()
analyses = SUAVE.Analyses.Vehicle()
atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976()
atmosphere.features.planet = SUAVE.Analyses.Planets.Planet()
analyses.append(atmosphere)
results = propeller_single_point(vehicle.networks.battery_propeller,
analyses,
pitch=0.,
omega=2200. * Units.rpm,
altitude=5000. * Units.ft,
delta_isa=0.,
speed=10 * Units['m/s'],
plots=True,
print_results=True)
thrust = results.thrust
torque = results.torque
power = results.power
Cp = results.power_coefficient
etap = results.efficiency
thrust_r = 643.4365612076354
torque_r = 130.6985065893255
power_r = 30110.77432998669
Cp_r = 0.03843902555841082
etap_r = 0.21368980888905617
assert (np.abs(thrust - thrust_r) / thrust_r <
1e-6), "Propeller Single Point Regression Failed at Thrust Test"
assert (np.abs(torque - torque_r) / torque_r <
1e-6), "Propeller Single Point Regression Failed at Torque Test"
assert (np.abs(power - power_r) / power_r <
1e-6), "Propeller Single Point Regression Failed at Power Test"
assert (
np.abs(Cp - Cp_r) / Cp_r < 1e-6
), "Propeller Single Point Regression Failed at Power Coefficient Test"
assert (np.abs(etap - etap_r) / etap_r < 1e-6
), "Propeller Single Point Regression Failed at Efficiency Test"
return
def main():
vehicle = vehicle_setup()
analyses = SUAVE.Analyses.Vehicle()
atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976()
atmosphere.features.planet = SUAVE.Analyses.Planets.Planet()
analyses.append(atmosphere)
results = propeller_single_point(vehicle.propulsors.battery_propeller,
analyses,
pitch=0.,
omega=1500. * Units.rpm,
altitude=5000. * Units.ft,
delta_isa=0.,
speed=10 * Units['m/s'],
plots=True,
print_results=True)
thrust = results.thrust
torque = results.torque
power = results.power
Cp = results.power_coefficient
etap = results.efficiency
thrust_r = 2388.4192996911806
torque_r = 853.6979972278123
power_r = 134098.56782376074
Cp_r = 0.3033014877238663
etap_r = 0.17810923251843858
assert (np.abs(thrust - thrust_r) / thrust_r <
1e-6), "Propeller Single Point Regression Failed at Thrust Test"
assert (np.abs(torque - torque_r) / torque_r <
1e-6), "Propeller Single Point Regression Failed at Torque Test"
assert (np.abs(power - power_r) / power_r <
1e-6), "Propeller Single Point Regression Failed at Power Test"
assert (
np.abs(Cp - Cp_r) / Cp_r < 1e-6
), "Propeller Single Point Regression Failed at Power Coefficient Test"
assert (np.abs(etap - etap_r) / etap_r < 1e-6
), "Propeller Single Point Regression Failed at Efficiency Test"
return
def electric_V_h_diagram(vehicle,
analyses,
CL_max,
delta_isa=0.,
grid_points=20.,
altitude_ceiling=2e4 * Units.ft,
max_speed=130 * Units['m/s'],
test_omega=800. * Units.rpm,
display_plot=True,
climb_rate_contours=[0.]):
"""electric_V_h_diagram(vehicle,
analyses,
delta_isa = 0.,
grid_points = 20.,
altitude_ceiling = 2e4 * Units.ft,
max_speed = 130 * Units['m/s'],
test_omega = 800. * Units.rpm,
display_plot = True,
climb_rate_contours = [0.]
):
Calculates and optionally displays climb rate and contours thereof over
a specified airspeed and altitude range. Climb rate determination ref.
Raymer, "Aircraft Design: A Conceptual Approach"
Sources:
D. Raymer, "Aircraft Design: A Conceptual Approach"
Assumptions:
Assumes use of Battery Propeller Energy Network
Inputs:
vehicle SUAVE Vehicle Structure
.mass_properties
.takeoff [kg]
analyses SUAVE Analyses Structure
.atmosphere
.planet
.sea_level_gravity [m/s^2]
delta_isa ISA Temperature Offset [deg. K/C]
grid_points Num. Test Points per Dim. [Int]
altitude_ceiling Maximum Test Altitude [User Set]
max_speed Maximum Test Speed [User Set]
test_omega Maximum Power Prop Speed [User Set]
display_plot Flag for Plot Generation [Boolean]
climb_rate_contours Climb Rates to Display [ft/min]
Outputs:
climb_rate Climb Rates at Test Points [ft/min]
"""
# Unpack Inputs
g = analyses.atmosphere.planet.sea_level_gravity
W = vehicle.mass_properties.takeoff * g
S = vehicle.reference_area
# Single Point Mission for Drag Determination
def mini_mission(altitude, speed):
mission = SUAVE.Analyses.Mission.Sequential_Segments()
mission.tag = 'the_mission'
segment = SUAVE.Analyses.Mission.Segments.Single_Point.Set_Speed_Set_Altitude_No_Propulsion(
)
segment.tag = 'single_point'
segment.analyses.extend(analyses)
segment.altitude = altitude
segment.air_speed = speed
mission.append_segment(segment)
return mission
# Specify Altitude and Speed Sample Points
alt_range = np.linspace(0.,
altitude_ceiling,
num=grid_points,
endpoint=True)
speed_range = np.linspace(0., max_speed, num=grid_points, endpoint=False)
# Initialize Climb Rate Grid
climb_rate = np.zeros((grid_points, grid_points))
# Loop Through Altitude and Speed Gridpoints
for alt_idx in range(grid_points):
altitude = alt_range[alt_idx]
atmo_data = analyses.atmosphere.compute_values(altitude, delta_isa)
rho = atmo_data.density
Vs = np.sqrt(2 * W /
(rho * S * CL_max)) # Determine Vehicle Stall Speed
for speed_idx in range(grid_points):
V = speed_range[speed_idx]
if V > Vs: # Only Bother Calculating if Vehicle is Above Stall Speed
# Determine Vehicle Drag at Altitude and Speed
mission = mini_mission(altitude, V)
results = mission.evaluate()
D = -results.segments.single_point.conditions.frames.wind.drag_force_vector[
0][0]
# Determine Propeller Power at Altitude and Speed
P = propeller_single_point(
vehicle.propulsors.battery_propeller,
analyses,
pitch=0.,
omega=test_omega,
altitude=altitude,
delta_isa=0.,
speed=V).power
# Check if Propeller Power Exceeds Max Battery Power, Switch to Max Battery Power if So
P = np.min([
P, vehicle.propulsors.battery_propeller.battery.max_power
])
# Determine Climb Rate (ref. Raymer)
cr = 1 / W * (P - D * V)
# If Climb Rate is Negative, Replace with 0 for Easy Contour-Finding
climb_rate[speed_idx, alt_idx] = np.max([0., cr])
climb_rate = climb_rate / Units['ft/min']
if display_plot:
# Get Speed and Altitude to Agree with Climb Rate Dimensions
speed_space, alt_space = np.meshgrid(speed_range, alt_range)
speed_space = np.transpose(speed_space)
alt_space = np.transpose(alt_space) / Units.ft
# Make Contour Plot of Climb Rates
CS = plt.contour(speed_space,
alt_space,
climb_rate,
levels=climb_rate_contours)
plt.xlabel('Airspeed (m/s)')
plt.ylabel('Altitude (ft)')
plt.title('Climb Rate (ft/min)')
plt.clabel(CS)
plt.show()
return climb_rate