def test_01(self):
# Truth values from NASA RP 1046
Value = SA.alt2density(8000)
Truth = 0.06011
self.failUnless(RE(Value, Truth) <= 1e-5)
def test_01(self):
# Truth values from NASA RP 1046
Value = SA.alt2density(8000)
Truth = 0.06011
self.assertTrue(RE(Value, Truth) <= 1e-5)
def calcNeededThrust(self, m, h, u_g, w_g, curveR):
if (u_g < c.V_MIN):
return 0.
rho = SA.alt2density(h, 'm', 'kg/m**3')
#Bahnneigungswinkel [deg]
gamma = math.atan(float(w_g) / u_g)
tas = math.sqrt(u_g**2. + w_g**2.)
if (curveR == 0 or math.isnan(curveR)):
phi = 0.
else:
phi = math.atan(tas**2. * math.cos(gamma) / (c.g * curveR))
n = math.cos(gamma) / math.cos(phi)
F1 = (math.sin(gamma) * m * c.g)
F2 = ((self.w.C_W0 * c.S * rho * tas**2) / 2)
F3 = (self.w.k * 2 * (n * m * c.g)**2 / (rho * c.S * tas**2))
F = F1 + F2 + F3
if (F < 0):
return 0.
return F
def calcTakeOffParameter(self, m, h, s, propulsionType, propulsion):
P_increment = 10000.
P_to = 60000.
rho = SA.alt2density(h, 'm', 'kg/m**3')
v_abh = math.sqrt(2. * m * c.g / (rho * c.S * c.C_A_TAKEOFF))
a_req = v_abh**2 / (2 * s)
a_mean, F_0 = self.calcMeanAccelor(m, h, P_to, propulsionType,
propulsion.ice.getNmax())
while (abs(a_req - a_mean) > 0.000001):
if (a_mean > a_req and P_increment > 0):
P_increment = P_increment * (-0.1)
if (a_mean < a_req and P_increment < 0):
P_increment = P_increment * (-0.1)
#print("P -> " + str(P_to))
P_to += P_increment
a_mean, F_0 = self.calcMeanAccelor(m, h, P_to, propulsionType,
propulsion.ice.getNmax())
t_abh = v_abh / a_mean
s_abh = (a_mean / 2) * t_abh**2
if (self.verbose):
print("[Wing] a_mean = " + str(a_mean))
print("[Wing] t_abh = " + str(t_abh))
print("[Wing] s_abh = " + str(s_abh))
print("[Wing] P_to = " + str(P_to))
return P_to, t_abh, v_abh, F_0
def test_06(self):
# truth value calculated from program at:
# http://www.sworld.com.au/steven/space/atmosphere/
Value = SA.alt2density(65322, density_units="kg/m**3", alt_units="m")
Truth = 1.4296e-4
self.failUnless(RE(Value, Truth) <= 5e-5)
def test_02(self):
# test psf
# Truth values from NASA RP 1046
Value = SA.alt2density(49000)
Truth = 0.012215
self.assertTrue(RE(Value, Truth) <= 2e-5)
def test_03(self):
# test pa and m
# Truth values from NASA RP 1046
Value = SA.alt2density(25000, alt_units='m', density_units='kg/m**3')
Truth = 0.039466
self.assertTrue(RE(Value, Truth) <= 1e-5)
def test_06(self):
# truth value calculated from program at:
# http://www.sworld.com.au/steven/space/atmosphere/
Value = SA.alt2density(65322, density_units='kg/m**3', alt_units='m')
Truth = 1.4296e-4
self.assertTrue(RE(Value, Truth) <= 5e-5)
def test_02(self):
# test psf
# Truth values from NASA RP 1046
Value = SA.alt2density(49000)
Truth = 0.012215
self.failUnless(RE(Value, Truth) <= 2e-5)
def test_03(self):
# test pa and m
# Truth values from NASA RP 1046
Value = SA.alt2density(25000, alt_units="m", density_units="kg/m**3")
Truth = 0.039466
self.failUnless(RE(Value, Truth) <= 1e-5)
def test_05(self):
# truth value calculated from program at:
# http://www.sworld.com.au/steven/space/atmosphere/
Value = SA.alt2density(49610, density_units='kg/m**3',
alt_units='m')
Truth = 1.0269e-3
self.failUnless(RE(Value, Truth) <= 5e-5)
def test_07(self):
# test units in other order
# truth value calculated from program at:
# http://www.sworld.com.au/steven/space/atmosphere/
Value = SA.alt2density(80956, density_units="kg/m**3", alt_units="m")
Truth = 1.3418e-5
self.failUnless(RE(Value, Truth) <= 3e-5)
def test_07(self):
# test units in other order
# truth value calculated from program at:
# http://www.sworld.com.au/steven/space/atmosphere/
Value = SA.alt2density(80956, density_units='kg/m**3', alt_units='m')
Truth = 1.3418e-5
self.assertTrue(RE(Value, Truth) <= 3e-5)
def test_04(self):
# test units in other order
# truth value calculated from program at:
# http://www.sworld.com.au/steven/space/atmosphere/
Value = SA.alt2density(39750, density_units='kg/m**3',
alt_units='m')
Truth = 3.9957e-3
self.failUnless(RE(Value, Truth) <= 3e-5)
def calcMeanAccelor(self, m, h, Pmax, propulsionType, NiceMax):
pr = Propeller()
rho = SA.alt2density(h, 'm', 'kg/m**3')
v_abh = math.sqrt(2. * m * c.g / (rho * c.S * c.C_A_TAKEOFF))
G = m * c.g
#Getribe...
P_to = Pmax * c.GEAR_EFF[propulsionType]
A_prop = pr.calcA_prop()
eta_prop_0 = 0.4 #geschaetzt
#aus Standschub.pdf
#F_0 = 0.4 * (2 * rho * A_prop * P_to**2)**(1./3.)
F_0 = eta_prop_0 * (P_to**(2. / 3.) * (2 * rho * A_prop)**(1. / 3.))
N_pr_to = NiceMax / c.GEAR_RATIO #1/min
a_vec = []
dt = 1.
t = 0.
v = 0.
a = 0.
s = 0.
while (v < v_abh):
v = v + a
#Thrust
eta = 0.5
if (v > 11):
eta, N = pr.calcEfficiency(h, v, N_pr_to, P_to)
F = min(F_0, eta * (P_to / (v + 0.01)))
#accelaration
A = c.C_A_TAKEOFF * c.S * (rho / 2) * v**2
W = c.C_W_TAKEOFF * c.S * (rho / 2) * v**2
a = (F - W - (c.WHEEL_MY * (G - A))) / m
a_vec.append(a)
t += dt
if (t > 1200):
a_mean = np.inf
a_vec.append(np.inf)
break
a_mean = np.mean(a_vec)
return a_mean, F_0
def calcCa(self, m, h, u_g):
if (u_g <= 0.):
return 0.
rho = SA.alt2density(h, 'm', 'kg/m**3')
C_A = (math.sqrt(2. * m * c.g / (c.S * rho)) * (1. / u_g))**2.
return C_A
def calcV_W_min(self, m, h):
rho = SA.alt2density(h, 'm', 'kg/m**3')
V_W_min = math.sqrt(2. * m * c.g /
(rho * c.S * math.sqrt(self.C_W0 / self.k)))
return V_W_min
def calcU_g_dH_min(self, m, h):
rho = SA.alt2density(h, 'm', 'kg/m**3')
U_g_dH_min = math.sqrt(
2. * m * c.g / (rho * c.S * math.sqrt(3. * self.C_W0 / self.k)))
return U_g_dH_min
def calcV(self, m, h, C_A):
rho = SA.alt2density(h, 'm', 'kg/m**3')
gamma = math.atan(self.calcC_WFromC_A(C_A) / C_A)
V = math.sqrt(2 * m * c.g * math.cos(gamma) / (rho * C_A * c.S))
return V
def calcCp(self, h, N, Pshaft):
if (N <= 0):
return float('nan')
rho = SA.alt2density(h, 'm', 'kg/m**3')
Cp = 100 * Pshaft / (rho * (N / 60)**3 * c.PROP_D**5)
return Cp
def plotTakeOffRun(self, m, h):
pr = Propeller()
rho = SA.alt2density(h, 'm', 'kg/m**3')
v_abh = math.sqrt(2 * m * c.g / (rho * c.S * c.C_A_TAKEOFF))
G = m * c.g
#Getribe...
P_to = c.GEAR_EFF_COMB * 84500 #kW
A_prop = pr.calcA_prop()
#aus Standschub.pdf
eta_prop_0 = 0.4 #geschaetzt
F_0 = eta_prop_0 * (P_to**(2. / 3.) * (2 * rho * A_prop)**(1. / 3.))
#F_0 = 0.4 * (2 * rho * A_prop * P_to**2)**(1./3.)
#F_0 = 1800 #MUELL!!!!!!!!!!!!!!!
N_pr_to = 5800. / c.GEAR_RATIO #1/min
#v_abh = 100
t_vec = []
v_vec = []
F_vec = []
A_vec = []
W_vec = []
a_vec = []
t = 0
v = 0
a = 0
while (v < v_abh):
t_vec.append(t)
#speed
v = v + a
v_vec.append(v)
#Thrust
N = N_pr_to
eta = 0.5
if (v > 11):
eta, N = pr.calcEfficiency(h, v, N_pr_to, P_to)
F = min(F_0, eta * (P_to / (v + 0.01)))
print(
str(v) + " -> " + str(eta) + " -> " + str(F) + " -> " + str(N))
F_vec.append(F)
#accelaration
A = c.C_A_TAKEOFF * c.S * (rho / 2) * v**2
A_vec.append(A)
W = c.C_W_TAKEOFF * c.S * (rho / 2) * v**2
W_vec.append(W)
a = (F - W - (c.WHEEL_MY * (G - A))) / m
a_vec.append(a)
t += 1
a_mean = np.mean(a_vec)
t_abh = v_abh / a_mean
s_abh = (a_mean / 2) * t_abh**2
print("t_abh = " + str(t_abh))
print("s_abh = " + str(s_abh))
#plt.plot(t_vec, F_vec, label="A")
plt.plot(t_vec, A_vec, label="A")
#plt.plot(t_vec, W_vec, label="W")
#plt.plot(t_vec, a_vec, "o-", label="a")
#plt.plot(t_vec, v_vec, "x-", label="v")
plt.xlabel("$Zeit [s]$")
plt.legend()
plt.show()
return s_abh
def calcCw(self, m, h, u_g, w_g):
rho = SA.alt2density(h, 'm', 'kg/m**3')
c_w = w_g * self.calcCa(m, h, u_g)**(3. / 2.) / math.sqrt(
2. * m * c.g / (c.S * rho))
return c_w
def calcC_W0(self):
rho = SA.alt2density(0, 'm', 'kg/m**3')
C_W0 = (2 * c.MTOM * c.g / (rho * c.S * c.V_E_MAX**2))**2 * self.k
return C_W0
