fix tail flex model to use theta from bending model

gpkitmodels/GP/aircraft/tail/empennage.py

@@ -46,9 +46,10 @@ def setup(self):
         l = self.l = self.tailboom.l
 
         state = TailBoomState()
-        loading = [self.tailboom.hbending(self.tailboom, self.htail, state),
-                   self.tailboom.vbending(self.tailboom, self.vtail, state),
-                   self.tailboom.vtorsion(self.tailboom, self.vtail, state)]
+        self.hbend = self.tailboom.hbending(self.tailboom, self.htail, state)
+        self.vbend = self.tailboom.vbending(self.tailboom, self.vtail, state)
+        self.vtor = self.tailboom.vtorsion(self.tailboom, self.vtail, state)
+        loading = [self.hbend, self.vbend, self.vtor]
 
         constraints = [
             W/mfac >= sum(c.W for c in self.components),

gpkitmodels/GP/aircraft/tail/tail_boom.py

@@ -164,9 +164,9 @@ def setup(self, tailboom, htail, state):
         Vne = self.Vne = state.Vne
         CLmax = htail.planform.CLmax
 
-        return [F >= 0.5*rhosl*Vne**2*S*CLmax,
+        return [F >= 0.5*rhosl*Vne**2*S,
                 th >= F*l**2/E/I0*(1+k)/2,
-                th <= thmax,
+                th*CLmax <= thmax,
                ]
 
 class TailBoom(Model):

gpkitmodels/SP/aircraft/tail/tail_boom_flex.py

@@ -1,30 +1,48 @@
 " tail boom flexibility "
-import numpy as np
-from gpkit import Model, Variable, SignomialsEnabled
+from numpy import pi
+from gpkit import Model, parse_variables, SignomialsEnabled
 
 class TailBoomFlexibility(Model):
-    "tail boom flexibility model"
-    def setup(self, htail, tailboom, wing, state):
+    """ Tail Boom Flexibility Model
 
-        Fne = Variable("F_{NE}", "-", "tail boom flexibility factor")
-        deda = Variable("d\\epsilon/d\\alpha", "-", "wing downwash derivative")
-        SMcorr = Variable("SM_{corr}", 0.55, "-", "corrected static margin")
+    Variables
+    ---------
+    Fne                 [-]     tail boom flexibility factor
+    deda                [-]     wing downwash derivative
+    SMcorr      0.55    [-]     corrected static margin
+    sph1                [-]     flexibility helper variable 1
+    sph2                [-]     flexibility helper variable 2
 
-        # signomial helper variables
-        sph1 = Variable("sph1", "-", "first term involving $V_h$")
-        sph2 = Variable("sph2", "-", "second term involving $V_h$")
+    LaTex Strings
+    -------------
+    Fne         F_{\mathrm{NE}}
+    deda        d\\epsilon/d\\alpha
+    SMcorr      SM_{\\mathrm{corr}}
+
+    """
+    def setup(self, htail, hbending, wing):
+        exec parse_variables(TailBoomFlexibility.__doc__)
+
+        mh = htail.mh
+        mw = wing.mw
+        Vh = htail.Vh
+        th = hbending.th
+        CLhmin = htail.CLhmin
+        CLwmax = wing.planform.CLmax
+        Sw = wing.planform.S
+        bw = wing.planform.b
+        lh = htail.lh
+        CM = wing.planform.CM
 
         constraints = [
-            Fne >= (1 + htail.mh*0.5*state.Vne**2*state.rhosl
-                    * htail["S"]*htail.lh**2/tailboom.E
-                    / tailboom.I0*tailboom.kfac),
-            sph1*(wing["m_w"]*Fne/htail.mh/htail.Vh) + deda <= 1,
-            sph2 <= htail.Vh*htail.CLhmin/wing.planform.CLmax,
+            Fne >= 1 + mh*th,
+            sph1*(mw*Fne/mh/Vh) + deda <= 1,
+            sph2 <= Vh*CLhmin/CLwmax,
             # (sph1 + sph2).mono_lower_bound({"sph1": .48, "sph2": .52}) >= (
             #     SMcorr + wing["C_M"]/wing["C_{L_{max}}"]),
-            deda >= wing["m_w"]*wing["S"]/wing["b"]/4/np.pi/htail.lh]
+            deda >= mw*Sw/bw/4/pi/lh]
 
         with SignomialsEnabled():
-            constraints.extend([sph1 + sph2 >= SMcorr + wing.planform.CM/wing.planform.CLmax])
+            constraints.extend([sph1 + sph2 >= SMcorr + CM/CLwmax])
 
         return constraints

gpkitmodels/SP/aircraft/wing/wing.py

@@ -1,18 +1,22 @@
 " wing.py "
 import numpy as np
-from gpkit.constraints.array import ArrayConstraint
 from gpkitmodels.GP.aircraft.wing.wing import Wing as WingGP
-from gpkit import Variable, SignomialsEnabled
+from gpkit import parse_variables, SignomialsEnabled
 
 #pylint: disable=attribute-defined-outside-init, invalid-name
 
 class Wing(WingGP):
+    """ SP wing model
 
+    Variables
+    ---------
+    mw          [-]     span wise effectiveness
+
+    """
     def setup(self, N=5):
+        exec parse_variables(Wing.__doc__)
 
         self.wing = WingGP.setup(self, N=N)
-        mw = Variable("m_w", "-", "span wise effectiveness")
-
         with SignomialsEnabled():
             constraints = [mw*(1 + 2/self.planform["AR"]) >= 2*np.pi]