def roca(altitude,
weight=2100,
press_drop=1.2,
temp='std',
temp_units='C',
prop_eff=0.7,
load_factor=1,
rated_power=275,
rpm=2700):
"""
Returns speed for best rate of climb and the rate of climb at that speed.
"""
MP = SA.alt2press(altitude) - press_drop
pwr = O.pwr(rpm, MP, altitude, temp=temp,
temp_units=temp_units) * rated_power / 180
roc_max = -100000
eass = range(60, 150, 1)
rocs = []
for eas in eass:
rocs.append((roc(altitude,
eas,
weight,
pwr,
2700,
temp=temp,
prop_eff=prop_eff,
load_factor=load_factor), eas))
mroc, meas = max(rocs)
return meas, mroc
def WOT_speed(altitude, weight = 2100, rpm = 2700, temp = 'std', \
temp_units = 'C', rv = 'F1', wing_area = 102, speed_units = 'kt', \
prop_eff = 0.78, MP_loss = 1.322, ram = 0.5, rated_power=275):
"""
Returns the predicted speed at full throttle.
The MP_loss is the MP lost in the induction tract at full throttle at 2700
rpm at MSL. The default value is from the Lycoming power charts.
The ram is the percentage of available ram recovery pressure that is
achieved in the MP.
"""
press = SA.alt2press(altitude, press_units = 'in HG')
MP_loss = MP_loss * (rpm / 2700.) ** 2
cas_guess = 300
error = 1
while error > 0.0001:
dp = A.cas2dp(cas_guess, press_units = 'in HG')
# print 'dp =', dp
ram_press = ram * dp
# print 'Ram rise =', ram_press
MP = press - MP_loss + ram_press
pwr = O.pwr(rpm, MP, altitude, temp = temp, temp_units = temp_units) * rated_power/180
print 'MP =', MP, 'Power =', pwr
tas = speed(altitude, weight, pwr, rpm, temp = temp, \
temp_units = temp_units, rv = rv, wing_area = wing_area, \
speed_units = speed_units, prop_eff = prop_eff)
cas = A.tas2cas(tas, altitude, temp = temp, temp_units = temp_units)
error = M.fabs((cas - cas_guess) / cas)
cas_guess = cas
# print 'CAS =', cas, 'TAS =', tas
return tas
def WOT_speed(altitude, weight = 2100, rpm = 2700, temp = 'std', \
temp_units = 'C', rv = 'F1', wing_area = 102, speed_units = 'kt', \
prop_eff = 0.78, MP_loss = 1.322, ram = 0.5, rated_power=275):
"""
Returns the predicted speed at full throttle.
The MP_loss is the MP lost in the induction tract at full throttle at 2700
rpm at MSL. The default value is from the Lycoming power charts.
The ram is the percentage of available ram recovery pressure that is
achieved in the MP.
"""
press = SA.alt2press(altitude, press_units='in HG')
MP_loss = MP_loss * (rpm / 2700.)**2
cas_guess = 300
error = 1
while error > 0.0001:
dp = A.cas2dp(cas_guess, press_units='in HG')
# print 'dp =', dp
ram_press = ram * dp
# print 'Ram rise =', ram_press
MP = press - MP_loss + ram_press
pwr = O.pwr(rpm, MP, altitude, temp=temp,
temp_units=temp_units) * rated_power / 180
print('MP =', MP, 'Power =', pwr)
tas = speed(altitude, weight, pwr, rpm, temp = temp, \
temp_units = temp_units, rv = rv, wing_area = wing_area, \
speed_units = speed_units, prop_eff = prop_eff)
cas = A.tas2cas(tas, altitude, temp=temp, temp_units=temp_units)
error = M.fabs((cas - cas_guess) / cas)
cas_guess = cas
# print 'CAS =', cas, 'TAS =', tas
return tas
def roca(altitude, weight = 2100, press_drop = 1.2, temp = 'std', \
temp_units='C', prop_eff = 0.7, load_factor =1, rated_power=275, \
rpm=2700):
"""
Returns speed for best rate of climb and the rate of climb at that speed.
"""
MP = SA.alt2press(altitude) - press_drop
pwr = O.pwr(rpm, MP, altitude, temp = temp, temp_units = temp_units) * rated_power/180
roc_max = -100000
eass = range(60, 150, 1)
rocs = []
for eas in eass:
rocs.append((roc(altitude, eas, weight, pwr, 2700, temp = temp, \
prop_eff = prop_eff, load_factor = load_factor),eas))
mroc, meas = max(rocs)
return meas, mroc