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SimPleAC now a class, adding main method.
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@1ozturkbe
1ozturkbe committed Oct 11, 2017
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Showing 1 changed file with 94 additions and 86 deletions.
180 changes: 94 additions & 86 deletions gpkitmodels/SP/SimPleAC/SimPleAC.py
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from gpkit import Variable, Model, SignomialsEnabled, VarKey, units
from gpkit import Model, Variable, SignomialsEnabled, VarKey, units
import numpy as np
import matplotlib.pyplot as plt

def SimPleAC():
# Env. constants
g = Variable("g", 9.81, "m/s^2", "gravitational acceleration")
mu = Variable("\\mu", 1.775e-5, "kg/m/s", "viscosity of air", pr=4.)
rho = Variable("\\rho", 1.23, "kg/m^3", "density of air", pr=5.)
rho_f = Variable("\\rho_f", 817, "kg/m^3", "density of fuel")

# Non-dimensional constants
C_Lmax = Variable("C_{L,max}", 1.6, "-", "max CL with flaps down", pr=5.)
e = Variable("e", 0.92, "-", "Oswald efficiency factor", pr=3.)
k = Variable("k", 1.17, "-", "form factor", pr=10.)
N_ult = Variable("N_{ult}", 3.3, "-", "ultimate load factor", pr=15.)
S_wetratio = Variable("(\\frac{S}{S_{wet}})", 2.075, "-", "wetted area ratio", pr=3.)
tau = Variable("\\tau", 0.12, "-", "airfoil thickness to chord ratio", pr=10.)
W_W_coeff1 = Variable("W_{W_{coeff1}}", 2e-5, "1/m",
"wing weight coefficent 1", pr= 30.) #orig 12e-5
W_W_coeff2 = Variable("W_{W_{coeff2}}", 60., "Pa",
"wing weight coefficent 2", pr=10.)
p_labor = Variable('p_{labor}',1.,'1/min','cost of labor', pr = 20.)
class SimPleAC(Model):
def setup(self):
# Env. constants
g = Variable("g", 9.81, "m/s^2", "gravitational acceleration")
mu = Variable("\\mu", 1.775e-5, "kg/m/s", "viscosity of air", pr=4.)
rho = Variable("\\rho", 1.23, "kg/m^3", "density of air", pr=5.)
rho_f = Variable("\\rho_f", 817, "kg/m^3", "density of fuel")

# Non-dimensional constants
C_Lmax = Variable("C_{L,max}", 1.6, "-", "max CL with flaps down", pr=5.)
e = Variable("e", 0.92, "-", "Oswald efficiency factor", pr=3.)
k = Variable("k", 1.17, "-", "form factor", pr=10.)
N_ult = Variable("N_{ult}", 3.3, "-", "ultimate load factor", pr=15.)
S_wetratio = Variable("(\\frac{S}{S_{wet}})", 2.075, "-", "wetted area ratio", pr=3.)
tau = Variable("\\tau", 0.12, "-", "airfoil thickness to chord ratio", pr=10.)
W_W_coeff1 = Variable("W_{W_{coeff1}}", 2e-5, "1/m",
"wing weight coefficent 1", pr= 30.) #orig 12e-5
W_W_coeff2 = Variable("W_{W_{coeff2}}", 60., "Pa",
"wing weight coefficent 2", pr=10.)
p_labor = Variable('p_{labor}',1.,'1/min','cost of labor', pr = 20.)

# Dimensional constants
CDA0 = Variable("(CDA0)", "m^2", "fuselage drag area") #0.035 originally
Range = Variable("Range",3000, "km", "aircraft range")
toz = Variable("toz", 1, "-", pr=15.)
TSFC = Variable("TSFC", 0.6, "1/hr", "thrust specific fuel consumption")
V_min = Variable("V_{min}", 25, "m/s", "takeoff speed", pr=20.)
W_0 = Variable("W_0", 6250, "N", "aircraft weight excluding wing", pr=20.)

# Free Variables
LoD = Variable('L/D','-','lift-to-drag ratio')
D = Variable("D", "N", "total drag force")
V = Variable("V", "m/s", "cruising speed")
W = Variable("W", "N", "total aircraft weight")
Re = Variable("Re", "-", "Reynold's number")
C_D = Variable("C_D", "-", "drag coefficient")
C_L = Variable("C_L", "-", "lift coefficient of wing")
C_f = Variable("C_f", "-", "skin friction coefficient")
W_f = Variable("W_f", "N", "fuel weight")
V_f = Variable("V_f", "m^3", "fuel volume")
V_f_avail = Variable("V_{f_{avail}}","m^3","fuel volume available")
T_flight = Variable("T_{flight}", "hr", "flight time")

# Free variables (fixed for performance eval.)
A = Variable("A", "-", "aspect ratio",fix = True)
S = Variable("S", "m^2", "total wing area", fix = True)
W_w = Variable("W_w", "N", "wing weight")#, fix = True)
W_w_strc = Variable('W_w_strc','N','wing structural weight', fix = True)
W_w_surf = Variable('W_w_surf','N','wing skin weight', fix = True)
V_f_wing = Variable("V_f_wing",'m^3','fuel volume in the wing', fix = True)
V_f_fuse = Variable('V_f_fuse','m^3','fuel volume in the fuselage', fix = True)
constraints = []
# Dimensional constants
Range = Variable("Range",3000, "km", "aircraft range")
# toz = Variable("toz", 1, "-", pr=15.)
TSFC = Variable("TSFC", 0.6, "1/hr", "thrust specific fuel consumption")
V_min = Variable("V_{min}", 25, "m/s", "takeoff speed", pr=20.)
W_0 = Variable("W_0", 6250, "N", "aircraft weight excluding wing", pr=20.)

# Free Variables
LoD = Variable('L/D','-','lift-to-drag ratio')
D = Variable("D", "N", "total drag force")
V = Variable("V", "m/s", "cruising speed")
W = Variable("W", "N", "total aircraft weight")
Re = Variable("Re", "-", "Reynold's number")
CDA0 = Variable("(CDA0)", "m^2", "fuselage drag area") #0.035 originally
C_D = Variable("C_D", "-", "drag coefficient")
C_L = Variable("C_L", "-", "lift coefficient of wing")
C_f = Variable("C_f", "-", "skin friction coefficient")
W_f = Variable("W_f", "N", "fuel weight")
V_f = Variable("V_f", "m^3", "fuel volume")
V_f_avail = Variable("V_{f_{avail}}","m^3","fuel volume available")
T_flight = Variable("T_{flight}", "hr", "flight time")
# Free variables (fixed for performance eval.)
A = Variable("A", "-", "aspect ratio",fix = True)
S = Variable("S", "m^2", "total wing area", fix = True)
W_w = Variable("W_w", "N", "wing weight")#, fix = True)
W_w_strc = Variable('W_w_strc','N','wing structural weight', fix = True)
W_w_surf = Variable('W_w_surf','N','wing skin weight', fix = True)
V_f_wing = Variable("V_f_wing",'m^3','fuel volume in the wing', fix = True)
V_f_fuse = Variable('V_f_fuse','m^3','fuel volume in the fuselage', fix = True)
constraints = []

# Drag model
C_D_fuse = CDA0 / S
C_D_wpar = k * C_f * S_wetratio
C_D_ind = C_L ** 2 / (np.pi * A * e)
constraints += [C_D >= C_D_fuse * toz + C_D_wpar / toz + C_D_ind * toz]
# Drag model
C_D_fuse = CDA0 / S
C_D_wpar = k * C_f * S_wetratio
C_D_ind = C_L ** 2 / (np.pi * A * e)
constraints += [C_D >= C_D_fuse + C_D_wpar + C_D_ind]

# Wing weight model
constraints += [W_w >= W_w_surf + W_w_strc,
# W_w_strc >= W_W_coeff1 * (N_ult * A ** 1.5 * ((W_0+V_f_fuse*g*rho_f) * W * S) ** 0.5) / tau, #[GP]
W_w_strc**2. >= W_W_coeff1**2. * (N_ult**2. * A ** 3. * ((W_0+V_f_fuse*g*rho_f) * W * S)) / tau**2.,
W_w_surf >= W_W_coeff2 * S]

# Weight and aerodynamics model
constraints += [LoD == C_L/C_D,
D >= 0.5 * rho * S * C_D * V ** 2,
Re <= (rho / mu) * V * (S / A) ** 0.5,
C_f >= 0.074 / Re ** 0.2,
T_flight >= Range / V,
W_0 + W_w + 0.5 * W_f <= 0.5 * rho * S * C_L * V ** 2,
W <= 0.5 * rho * S * C_Lmax * V_min ** 2,
W >= W_0 + W_w + W_f]
# Wing weight model
constraints += [W_w >= W_w_surf + W_w_strc,
# W_w_strc >= W_W_coeff1 * (N_ult * A ** 1.5 * ((W_0+V_f_fuse*g*rho_f) * W * S) ** 0.5) / tau, #[GP]
W_w_strc**2. >= W_W_coeff1**2. * (N_ult**2. * A ** 3. * ((W_0+V_f_fuse*g*rho_f) * W * S)) / tau**2.,
W_w_surf >= W_W_coeff2 * S]
# Weight and aerodynamics model
constraints += [LoD == C_L/C_D,
D >= 0.5 * rho * S * C_D * V ** 2,
Re <= (rho / mu) * V * (S / A) ** 0.5,
C_f >= 0.074 / Re ** 0.2,
T_flight >= Range / V,
W_0 + W_w + 0.5 * W_f <= 0.5 * rho * S * C_L * V ** 2,
W <= 0.5 * rho * S * C_Lmax * V_min ** 2,
W >= W_0 + W_w + W_f]

# Fuel volume model
with SignomialsEnabled():
constraints +=[V_f == W_f / g / rho_f,
V_f_avail <= V_f_wing + V_f_fuse, #[SP]
V_f_wing**2 <= 0.0009*S**3/A*tau**2, # linear with b and tau, quadratic with chord
V_f_fuse <= 10*units('m')*CDA0,
#TODO: Reduce volume available by the structure!
V_f_avail >= V_f,
W_f >= TSFC * T_flight * D]
# Fuel volume model
with SignomialsEnabled():
constraints +=[V_f == W_f / g / rho_f,
V_f_avail <= V_f_wing + V_f_fuse, #[SP]
V_f_wing**2 <= 0.0009*S**3/A*tau**2, # linear with b and tau, quadratic with chord
V_f_fuse <= 10*units('m')*CDA0,
#TODO: Reduce volume available by the structure!
V_f_avail >= V_f,
W_f >= TSFC * T_flight * D]

# return Model(W_f/LoD, constraints)
# return Model(D, constraints)
return Model(W_f, constraints)
# return Model(W,constraints)
# return Model(W_f*T_flight,constraints)
# return Model(W_f + 1*T_flight*units('N/min'),constraints)
return constraints
# return Model(W_f/LoD, constraints)
# return Model(D, constraints)
# return Model(W,constraints)
# return Model(W_f*T_flight,constraints)
# return Model(W_f + 1*T_flight*units('N/min'),constraints)

if __name__ == "__main__":
# Most basic way to execute the model
m = SimPleAC()
m.cost = m['W_f']
sol = m.localsolve(verbosity = 4)
print sol.table()

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