Merge 9b73381 into e813aad

tests/test_multhop.py

@@ -0,0 +1,38 @@
+import numpy as np
+
+from wingstructure.aero import multhop
+
+
+# test low level functions
+
+def test_multhop_solve():
+    """test multhop_solve with numeric data from schlichting book    
+    """
+
+
+    Λ = 6 # aspect ratio of wing
+
+    b = 15 # m span width
+    S = b**2/Λ
+
+    cs = np.array([b/Λ]*2) # depth of wing
+    ys = np.array([0,b/2]) # section positions
+
+    αs = np.array([1]*2) # angle of attack
+    dcls = np.array([2*np.pi]*2)
+
+    # reference result from Schlichting
+    ηs_ref = np.array([0,0.3827,0.7071,0.9239,1])
+    γs_ref = np.array([0.4320,0.4192,0.3710,0.2485,0])
+
+    # coarse calculation
+    M = 7
+
+    solverinput = multhop._prepare_multhop(ys, αs, cs, dcls, S, b, M)
+
+    calc_ys = solverinput[0]
+
+    γs = multhop._multhop_solve(*solverinput[1:], b)
+
+    assert np.isclose(calc_ys[M//2:]/b*2, ηs_ref[:-1], atol=1e-4).all()
+    assert np.isclose(γs[M//2:], γs_ref[:-1], atol=1e-4).all()

wingstructure/aero/__init__.py

@@ -1,3 +1,3 @@
 from . import analysis, liftingline, nnliftingline, polarinterp
 
-from .analysis import AirfoilData, LiftAnalysis, LiftAndMomentAnalysis
+from .liftingline import AirfoilData, LiftAnalysis, calculate

wingstructure/aero/analysis.py

@@ -79,6 +79,7 @@ def get_α0(airfoil, airfoil_db):
             self.airbrake_distribution, self.airbrake_lift, self.airbrake_drag = multhopp_(α_ab)
 
         ## lift due to angle of attack
+        #print('\n\naoa')
         α_aoa = np.ones(M)
         self.aoa_c_ls, aoa_C_L, self.aoa_C_Di = multhopp_(α_aoa)
         self.aoa_c_ls /= aoa_C_L
@@ -90,7 +91,7 @@ def _calculate_flap_α(self, flap, angle=np.radians(1)):
 
         for ii, span_pos in enumerate(self.calc_ys):
 
-            if flap.chordpos_at(span_pos) >= 0.0 and span_pos > 0:
+            if flap.length(span_pos) > 0.0 and span_pos > 0:
 
                 lambda_k = 1-flap.chordpos_at(span_pos)