def setup(self, static, state):
Pshaft = Variable("P_{shaft}", "hp", "Shaft power")
bsfc = Variable("BSFC", "kg/kW/hr", "Brake specific fuel consumption")
Pavn = Variable("P_{avn}", 40, "watts", "Avionics power")
Ptotal = Variable("P_{total}", "hp", "Total power, avionics included")
eta_alternator = Variable("\\eta_{alternator}", 0.8, "-",
"alternator efficiency")
href = Variable("h_{ref}", 1000, "ft", "reference altitude")
h_vals = state.substitutions("h")
if len(href) == 1:
h_vals = [h_vals]
lfac = [-0.035*(v/hr.value) + 1.0
for v, hr in zip(h_vals, href)]
Leng = Variable("L_{eng}", lfac, "-", "shaft power loss factor")
Pshaftmax = Variable("P_{shaft-max}",
"hp", "Max shaft power at altitude")
mfac = Variable("m_{fac}", 1.0, "-", "BSFC margin factor")
path = os.path.dirname(__file__)
df = pd.read_csv(path + os.sep + "powerBSFCfit.csv").to_dict(
orient="records")[0]
constraints = [
FitCS(df, bsfc/mfac/static["BSFC_{min}"], [Ptotal/Pshaftmax]),
Pshaftmax/static["P_{sl-max}"] == Leng,
Pshaftmax >= Ptotal,
Ptotal >= Pshaft + Pavn/eta_alternator
]
return constraints
def setup(self, aircraft, sp=False):
fs = FlightState()
A = Variable("A", "m/s**2", "log fit equation helper 1")
B = Variable("B", "1/m", "log fit equation helper 2")
g = Variable("g", 9.81, "m/s**2", "gravitational constant")
mu = Variable("\\mu_b", 0.025, "-", "coefficient of friction")
T = Variable("T", "lbf", "take off thrust")
cda = Variable("CDA", 0.024, "-", "parasite drag coefficient")
CLg = Variable("C_{L_g}", "-", "ground lift coefficient")
CDg = Variable("C_{D_g}", "-", "grag ground coefficient")
cdp = Variable("c_{d_{p_{stall}}}", 0.025, "-",
"profile drag at Vstallx1.2")
Kg = Variable("K_g", 0.04, "-", "ground-effect induced drag parameter")
CLto = Variable("C_{L_{TO}}", 3.5, "-", "max lift coefficient")
Vstall = Variable("V_{stall}", "knots", "stall velocity")
e = Variable("e", 0.8, "-", "span efficiency")
zsto = Variable("z_{S_{TO}}", "-", "take off distance helper variable")
Sto = Variable("S_{TO}", "ft", "take off distance")
Sground = Variable("S_{ground}", "ft", "ground roll")
etaprop = Variable("\\eta_{prop}", 0.8, "-", "propellor efficiency")
msafety = Variable("m_{fac}", 1.4, "-", "safety margin")
path = os.path.dirname(os.path.abspath(__file__))
df = pd.read_csv(path + os.sep + "logfit.csv")
fd = df.to_dict(orient="records")[0]
constraints = [
T / aircraft.topvar("W") >= A / g + mu,
T <= aircraft["P_{shaft-max}"] * etaprop / fs["V"],
CDg >= 0.024 + cdp + CLto**2 / pi / aircraft["AR"] / e,
Vstall == (2 * aircraft.topvar("W") / fs["\\rho"] /
aircraft.wing["S"] / CLto)**0.5,
fs["V"] == 1.3 * Vstall,
FitCS(fd, zsto, [A / g, B * fs["V"]**2 / g]),
Sground >= 1.0 / 2.0 / B * zsto, Sto / msafety >= Sground
]
if sp:
with SignomialsEnabled():
constraints.extend([
(B * aircraft.topvar("W") / g +
0.5 * fs["\\rho"] * aircraft.wing["S"] * mu * CLto >=
0.5 * fs["\\rho"] * aircraft.wing["S"] * CDg)
])
else:
constraints.extend([
B >= (g / aircraft.topvar("W") * 0.5 * fs["\\rho"] *
aircraft.wing["S"] * CDg)
])
return constraints, fs
def setup(self, aircraft):
fs = FlightState()
A = Variable("A", "m/s**2", "log fit equation helper 1")
B = Variable("B", "1/m", "log fit equation helper 2")
g = Variable("g", 9.81, "m/s**2", "gravitational constant")
mu = Variable("\\mu", 0.5, "-", "Braking coefficient of friction")
T_rev = Variable("T", "N", "Reverse thrust")
cda = Variable("CDA", 0.024, "-", "parasite drag coefficient")
CLg = Variable("C_{L_g}", "-", "ground lift coefficient")
CDg = Variable("C_{D_g}", "-", "grag ground coefficient")
Vstall = Variable("V_{stall}", "knots", "stall velocity")
Sgr = Variable("S_{gr}", "ft", "landing ground roll")
Slnd = Variable("S_{land}", "ft", "landing distance")
etaprop = Variable("\\eta_{prop}", 0.05, "-", "propellor efficiency")
msafety = Variable("m_{fac}", 1.4, "-", "Landing safety margin")
CLland = Variable("C_{L_{land}}", 3.5, "-", "landing CL")
cdp = Variable("c_{d_{p_{stall}}}", 0.025, "-",
"profile drag at Vstallx1.2")
V_ref = Variable("V_{ref}", "kts", "Approach reference speed")
f_ref = Variable("f_{ref}", 1.3, "-",
"Approach reference speed margin above stall")
path = os.path.dirname(os.path.abspath(__file__))
df = pd.read_csv(path + os.sep + "logfit.csv")
fd = df.to_dict(orient="records")[0]
constraints = [
T_rev == aircraft["P_{shaft-max}"] * etaprop / fs["V"],
Vstall == (2. * aircraft.topvar("W") / fs["\\rho"] /
aircraft["S"] / CLland)**0.5,
fs["V"] >= f_ref * Vstall,
V_ref == fs["V"],
Slnd >= msafety * Sgr,
FitCS(fd, Sgr * 2 * B, [A / g, B * fs["V"]**2 / g]),
]
with SignomialsEnabled():
constraints.extend([
TCS([(B * aircraft.topvar("W") / g +
0.5 * fs["\\rho"] * aircraft["S"] * CDg >=
0.5 * fs["\\rho"] * aircraft["S"] * mu * CLland)]),
TCS([A / g <= T_rev / aircraft.topvar("W") + mu]),
CDg <=
cda + cdp + CLland**2 / pi / aircraft["AR"] / aircraft["e"],
])
return constraints, fs
def setup(self, wing, state, out=False):
exec parse_variables(GustL.__doc__)
self.load = SparLoading.setup(self, wing, state, out=out)
cbar = self.wing.planform.cbar
W = self.W # from SparLoading
q = self.q
N = self.N
b = self.b
path = os.path.dirname(os.path.abspath(__file__))
df = pd.read_csv(path + os.sep + "arctan_fit.csv").to_dict(
orient="records")[0]
constraints = [
# fit for arctan from 0 to 1, RMS = 0.044
FitCS(df, agust, [cosminus1*vgust/v]),
q >= W*N/b*cbar*(1 + 2*pi*agust/cl*(1+Ww/W)),
]
return self.load, constraints
def setup(self, wing):
exec parse_variables(GustL.__doc__)
self.load = SparLoading.setup(self, wing)
self.b = self.wing.planform.b
self.I = self.wing.spar.I
self.Sy = self.wing.spar.Sy
self.cave = self.wing.planform.cave
self.tshear = self.wing.spar.tshear
path = os.path.dirname(os.path.abspath(__file__))
df = pd.read_csv(path + os.sep +
"arctan_fit.csv").to_dict(orient="records")[0]
constraints = [
# fit for arctan from 0 to 1, RMS = 0.044
FitCS(df, agust, [cosminus1 * vgust / v]),
self.beam["\\bar{q}"] >= self.wing.planform.cbar *
(1 + 2 * pi * agust / cl * (1 + Ww / self.W)),
]
return self.load, constraints
def setup(self, DF70=False):
self.DF70 = DF70
W = Variable("W", "lbf", "Installed/Total engine weight")
mfac = Variable("m_{fac}", 1.0, "-", "Engine weight margin factor")
bsfc_min = Variable("BSFC_{min}", 0.3162, "kg/kW/hr", "minimum BSFC")
Pref = Variable("P_{ref}", 10.0, "hp", "Reference shaft power")
Wengref = Variable("W_{eng-ref}", 10.0, "lbf",
"Reference engine weight")
Weng = Variable("W_{eng}", "lbf", "engine weight")
Pslmax = Variable("P_{sl-max}", "hp",
"Max shaft power at sea level")
path = os.path.dirname(__file__)
df = pd.read_csv(path + os.sep + "power_lawfit.csv").to_dict(
orient="records")[0]
constraints = [
FitCS(df, Weng/Wengref, [Pslmax/Pref]),
W/mfac >= 2.572*Weng**0.922*units("lbf")**0.078]
return constraints