Propeller computation change

Wasn't part of the original PR but still made some change. We were unnecessarily extensive on how many propeller pitch we wre testing. Now we only do it once per degree before it was more every third of degree. Also attempted to provide smart initial values to the induced speed but it makes the low speed not converge 😦

integration_tests/oad_process/test_oad_process.py

@@ -117,9 +117,9 @@ def test_oad_process_vlm_be76(cleanup):
     assert_allclose(problem.get_val("data:mission:sizing:fuel", units="kg"), 258.0, atol=1)
     assert_allclose(problem["data:handling_qualities:stick_fixed_static_margin"], 0.25, atol=1e-2)
     # noinspection PyTypeChecker
-    assert_allclose(problem.get_val("data:weight:aircraft:MTOW", units="kg"), 1747.0, atol=1)
+    assert_allclose(problem.get_val("data:weight:aircraft:MTOW", units="kg"), 1748.0, atol=1)
     # noinspection PyTypeChecker
-    assert_allclose(problem.get_val("data:weight:aircraft:OWE", units="kg"), 1109.0, atol=1)
+    assert_allclose(problem.get_val("data:weight:aircraft:OWE", units="kg"), 1110.0, atol=1)
 
 
 def test_oad_process_tbm_900(cleanup):
@@ -194,10 +194,10 @@ def test_oad_process_vlm_mission_vector(cleanup):
     _check_weight_performance_loop(problem)
 
     # noinspection PyTypeChecker
-    assert_allclose(problem.get_val("data:mission:sizing:fuel", units="kg"), 252.0, atol=1)
+    assert_allclose(problem.get_val("data:mission:sizing:fuel", units="kg"), 253.0, atol=1)
     assert_allclose(problem["data:handling_qualities:stick_fixed_static_margin"], 0.15, atol=1e-2)
     # noinspection PyTypeChecker
-    assert_allclose(problem.get_val("data:weight:aircraft:MTOW", units="kg"), 1656.0, atol=1)
+    assert_allclose(problem.get_val("data:weight:aircraft:MTOW", units="kg"), 1657.0, atol=1)
     # noinspection PyTypeChecker
     assert_allclose(problem.get_val("data:weight:aircraft:OWE", units="kg"), 1028.0, atol=1)
 

src/fastga/models/aerodynamics/external/propeller_code/compute_propeller_aero.py

@@ -231,7 +231,11 @@ def construct_table(self, inputs, speed_interp, altitude, omega):
 
         for v_inf in speed_interp:
             self.compute_extreme_pitch(inputs, v_inf)
-            theta_interp = np.linspace(self.theta_min, self.theta_max, 100)
+            # Compute performances for evenly space theta every degree
+            theta_interp = np.append(
+                np.arange(self.theta_min, self.theta_max, 1.0),
+                np.array([self.theta_max]),
+            )
             local_thrust_vect = []
             local_theta_vect = []
             local_eta_vect = []

src/fastga/models/aerodynamics/external/propeller_code/propeller_core.py

@@ -42,6 +42,10 @@ def __init__(self, **kwargs):
         self.theta_min = 0.0
         self.theta_max = 0.0
 
+        # Store values for induced velocities
+        self.vi_vect = None
+        self.vt_vect = None
+
     def initialize(self):
         self.options.declare("sections_profile_position_list", types=list)
         self.options.declare("sections_profile_name_list", types=list)
@@ -103,7 +107,16 @@ def compute_extreme_pitch(self, inputs, v_inf):
         self.theta_max = phi_75 + 25.0
 
     def compute_pitch_performance(
-        self, inputs, theta_75, v_inf, altitude, omega, radius, alpha_list, cl_list, cd_list
+        self,
+        inputs,
+        theta_75,
+        v_inf,
+        altitude,
+        omega,
+        radius,
+        alpha_list,
+        cl_list,
+        cd_list,
     ):
 
         """
@@ -142,8 +155,12 @@ def compute_pitch_performance(
         theta_75_ref = np.interp(0.75, radius_ratio_vect, twist_vect)
 
         # Initialise vectors
-        vi_vect = np.zeros_like(radius)
-        vt_vect = np.zeros_like(radius)
+        if self.vi_vect is None:
+            self.vi_vect = np.zeros_like(radius)
+
+        if self.vt_vect is None:
+            self.vt_vect = np.zeros_like(radius)
+
         thrust_element_vector = np.zeros_like(radius)
         torque_element_vector = np.zeros_like(radius)
         alpha_vect = np.zeros_like(radius)
@@ -182,8 +199,8 @@ def compute_pitch_performance(
                 method="hybr",
                 options={"xtol": 1e-3},
             ).x
-            vi_vect[idx] = speed_vect[0]
-            vt_vect[idx] = speed_vect[1]
+            self.vi_vect[idx] = speed_vect[0]
+            self.vt_vect[idx] = speed_vect[1]
             results = self.bem_theory(
                 speed_vect,
                 radius[idx],