Removal of Aircraft.Engine.REFERENCE_DIAMETER

aviary/docs/theory_guide/gasp_based_bwb.ipynb

@@ -15,8 +15,8 @@
     "\n",
     "from aviary.api import Aircraft\n",
     "from aviary.subsystems.geometry.gasp_based.engine import (\n",
-    "    BWBEngineSizeGroup,\n",
-    "    EngineSize,\n",
+    "    GASPEngineSizeGroup,\n",
+    "    GASPEngineSize,\n",
     "    PercentNotInFuselage,\n",
     ")\n",
     "from aviary.subsystems.geometry.gasp_based.fuselage import (\n",
@@ -33,8 +33,8 @@
     "glue_variable(get_variable_name(BWBFuselageParameters2), md_code=True)\n",
     "glue_variable(get_variable_name(BWBFuselageSize), md_code=True)\n",
     "glue_variable(get_variable_name(BWBFuselageGroup), md_code=True)\n",
-    "glue_variable(get_variable_name(EngineSize), md_code=True)\n",
-    "glue_variable(get_variable_name(BWBEngineSizeGroup), md_code=True)\n",
+    "glue_variable(get_variable_name(GASPEngineSize), md_code=True)\n",
+    "glue_variable(get_variable_name(GASPEngineSizeGroup), md_code=True)\n",
     "glue_variable(get_variable_name(PercentNotInFuselage), md_code=True)\n",
     "\n",
     "glue_variable(get_variable_name(Aircraft.Wing.VERTICAL_MOUNT_LOCATION), md_code=True)"
@@ -57,8 +57,8 @@
     "- {glue:md}`BWBFuselageParameters2`: This component computes several fuselage geometric parameters based on both the user inputs and cabin layout.\n",
     "- {glue:md}`BWBFuselageSize`: It carries out the computation of fuselage length and wetted area of BWB model.\n",
     "- {glue:md}`BWBFuselageGroup`: {glue:md}`BWBFuselageParameters1` + {glue:md}`BWBCabinLayout` + {glue:md}`BWBFuselageParameters2` + {glue:md}`BWBFuselageSize`\n",
-    "- {glue:md}`PercentNotInFuselage`: For BWB, engines may be partially buried into fuselage. This component computes the percentage of corresponding surface area of nacelles not buried in fuselage. This parameter is passed to {glue:md}`EngineSize` component which computes the wetted area of nacelle. This function has infinity derivatives at the two ends. We use two cubic polynomials to smooth it.\n",
-    "- {glue:md}`BWBEngineSizeGroup`: {glue:md}`PercentNotInFuselage` + {glue:md}`EngineSize`. For Tube+Wing aircraft, we assume that engines are not buried into fuselage and hence {glue:md}`EngineSize` is good enough. But this feature can be extended to conventional aircraft.\n",
+    "- {glue:md}`PercentNotInFuselage`: For BWB, engines may be partially buried into fuselage. This component computes the percentage of corresponding surface area of nacelles not buried in fuselage. This parameter is passed to {glue:md}`GASPEngineSize` component which computes the wetted area of nacelle. This function has infinity derivatives at the two ends. We use two cubic polynomials to smooth it.\n",
+    "- {glue:md}`GASPEngineSizeGroup`: {glue:md}`PercentNotInFuselage` + {glue:md}`GASPEngineSize`. For Tube+Wing aircraft, we assume that engines are not buried into fuselage and hence {glue:md}`GASPEngineSize` is good enough. But this feature can be extended to conventional aircraft.\n",
     "- {glue:md}`ExposedWing`: Computation of exposed wing area. This is useful for BWB, but is available to tube+wing model too. For {glue:md}`Aircraft.Wing.VERTICAL_MOUNT_LOCATION` in the range (0, 1), the function has infinity derivatives at the two ends. We use two cubic polynomials to smooth it."
    ]
   },

aviary/models/aircraft/large_single_aisle_1/V3_bug_fixed_IO.py

@@ -72,7 +72,7 @@
 V3_bug_fixed_options.set_val(Aircraft.Fuselage.WETTED_AREA, 4000, units='ft**2')
 V3_bug_fixed_options.set_val(Aircraft.VerticalTail.MOMENT_RATIO, 2.362, units='unitless')
 V3_bug_fixed_options.set_val(Aircraft.HorizontalTail.ASPECT_RATIO, val=4.75, units='unitless')
-V3_bug_fixed_options.set_val(Aircraft.Engine.REFERENCE_DIAMETER, 5.8, units='ft')
+V3_bug_fixed_options.set_val(Aircraft.Engine.INLET_AREA_COEFFICIENT, 0.00030975, units='unitless')
 V3_bug_fixed_options.set_val(Aircraft.Nacelle.CORE_DIAMETER_RATIO, 1.25, units='unitless')
 V3_bug_fixed_options.set_val(Aircraft.Nacelle.FINENESS, 2, units='unitless')
 

aviary/models/aircraft/large_single_aisle_1/large_single_aisle_1_GASP.csv

@@ -29,12 +29,12 @@ aircraft:design:type,transport,unitless
 aircraft:engine:additional_mass_fraction,0.14,unitless
 aircraft:engine:data_file,models/engines/turbofan_23k_1.csv,unitless
 aircraft:engine:global_throttle, True, unitless
+aircraft:engine:inlet_area_coefficient,0.000301265,unitless
 aircraft:engine:mass_scaler,1,unitless
 aircraft:engine:mass_specific,0.21366,lbm/lbf
 aircraft:engine:num_engines,2,unitless
 aircraft:engine:pod_mass_scaler,1,unitless
 aircraft:engine:pylon_factor,1.25,unitless
-aircraft:engine:reference_diameter,5.8,ft
 aircraft:engine:reference_sls_thrust,28690,lbf
 aircraft:engine:scale_factor,1.0,unitless
 aircraft:engine:scaled_sls_thrust,28690,lbf

aviary/models/aircraft/large_turboprop_freighter/large_turboprop_freighter_GASP.csv

@@ -64,7 +64,6 @@ aircraft:engine:propeller:diameter, 13.5, ft
 aircraft:engine:propeller:integrated_lift_coefficient, 0.5, unitless
 aircraft:engine:propeller:tip_speed_max, 720, ft/s
 aircraft:engine:pylon_factor, 0.7, unitless
-aircraft:engine:reference_diameter, 5.8, ft
 aircraft:engine:reference_sls_thrust, 5000, lbf
 aircraft:engine:rpm_design, 13820, rpm
 aircraft:engine:fixed_rpm, 13820, rpm

aviary/models/aircraft/small_single_aisle/small_single_aisle_GASP.csv

@@ -35,7 +35,6 @@ aircraft:engine:mass_specific,0.2153,lbm/lbf
 aircraft:engine:num_engines,2,unitless
 aircraft:engine:pod_mass_scaler,1,unitless
 aircraft:engine:pylon_factor,0.6,unitless
-aircraft:engine:reference_diameter,6.04,ft
 aircraft:engine:reference_sls_thrust,28690,lbf
 aircraft:engine:scale_factor,0.8295573370512374,unitless
 aircraft:engine:scaled_sls_thrust,23800,lbf

aviary/models/aircraft/test_aircraft/aircraft_for_bench_FwGm.csv

@@ -23,6 +23,7 @@ aircraft:engine:fuel_flow_scaler_constant_term,0.,unitless
 aircraft:engine:fuel_flow_scaler_linear_term,0.,unitless
 aircraft:engine:geopotential_alt,False,unitless
 aircraft:engine:ignore_negative_thrust,False,unitless
+aircraft:engine:inlet_area_coefficient,0.00030975,unitless
 aircraft:engine:interpolation_method,slinear,unitless
 aircraft:engine:mass_scaler,1.15,unitless
 aircraft:engine:mass,7400,lbm
@@ -32,7 +33,6 @@ aircraft:engine:num_fuselage_engines,0,unitless
 aircraft:engine:num_wing_engines,2,unitless
 aircraft:engine:pod_mass_scaler,1,unitless
 aircraft:engine:pylon_factor,1.25,unitless
-aircraft:engine:reference_diameter,5.8,ft
 aircraft:engine:reference_mass,7400,lbm
 aircraft:engine:reference_sls_thrust,28928.1,lbf
 aircraft:engine:scale_factor,1.0,unitless

aviary/models/aircraft/test_aircraft/aircraft_for_bench_GwFm.csv

@@ -38,7 +38,6 @@ aircraft:engine:mass_scaler,1,unitless
 aircraft:engine:num_engines,2,unitless
 aircraft:engine:pod_mass_scaler,1,unitless
 aircraft:engine:pylon_factor,1.25,unitless
-aircraft:engine:reference_diameter,5.8,ft
 aircraft:engine:reference_sls_thrust,28690,lbf
 aircraft:engine:scale_factor,1.0,unitless
 aircraft:engine:scaled_sls_thrust,28690,lbf

aviary/models/aircraft/test_aircraft/aircraft_for_bench_GwGm.csv

@@ -31,14 +31,14 @@ aircraft:electrical:system_mass_per_passenger,16.0,lbm
 aircraft:engine:additional_mass_fraction,0.135,unitless
 aircraft:engine:data_file,models/engines/turbofan_23k_1.csv,unitless
 aircraft:engine:global_throttle, True, unitless
+aircraft:engine:inlet_area_coefficient,0.000301265,unitless
 aircraft:engine:mass_scaler,1,unitless
 aircraft:engine:mass_specific,0.21366,lbm/lbf
 aircraft:engine:mass_scaler,1,unitless
 aircraft:engine:num_engines,2,unitless
 aircraft:engine:num_wing_engines,2,unitless
 aircraft:engine:pod_mass_scaler,1,unitless
 aircraft:engine:pylon_factor,1.25,unitless
-aircraft:engine:reference_diameter,5.8,ft
 aircraft:engine:reference_sls_thrust,28690,lbf
 aircraft:engine:scale_factor,1.0,unitless
 aircraft:engine:scaled_sls_thrust,28690,lbf

aviary/models/aircraft/test_aircraft/configuration_test_GASP.csv

@@ -35,7 +35,6 @@ aircraft:engine:mass_specific,0.21366,lbm/lbf
 aircraft:engine:num_engines,2,unitless
 aircraft:engine:pod_mass_scaler,1,unitless
 aircraft:engine:pylon_factor,1.25,unitless
-aircraft:engine:reference_diameter,6.15,ft
 aircraft:engine:reference_sls_thrust,28690,lbf
 aircraft:engine:scale_factor,0.7376089229696758,unitless
 aircraft:engine:scaled_sls_thrust,21162,lbf

aviary/subsystems/geometry/gasp_based/engine.py

@@ -159,26 +159,21 @@ def compute_partials(self, inputs, J):
         J['percent_exposed', Aircraft.Nacelle.PERCENT_DIAM_BURIED_IN_FUSELAGE] = d_pct_swn
 
 
-class EngineSize(om.ExplicitComponent):
+class GASPEngineSize(om.ExplicitComponent):
     """
-    GASP engine geometry calculation. It returns Aircraft.Nacelle.AVG_DIAMETER,
-    Nacelle.AVG_LENGTH, and Aircraft.Nacelle.SURFACE_AREA. This does not follow GASP
-    algorithm exactly.
+    Engine geometry calculation based on engine diameter. It returns Aircraft.Nacelle.AVG_DIAMETER,
+    Nacelle.AVG_LENGTH, and Aircraft.Nacelle.SURFACE_AREA. It follows the algorithm in GASP.
     """
 
     def initialize(self):
         add_aviary_option(self, Aircraft.Engine.NUM_ENGINES)
+        add_aviary_option(self, Aircraft.Engine.INLET_AREA_COEFFICIENT)
         add_aviary_option(self, Settings.VERBOSITY)
 
     def setup(self):
         num_engine_type = len(self.options[Aircraft.Engine.NUM_ENGINES])
 
-        add_aviary_input(
-            self, Aircraft.Engine.REFERENCE_DIAMETER, shape=num_engine_type, units='ft'
-        )
-        add_aviary_input(
-            self, Aircraft.Engine.SCALE_FACTOR, shape=num_engine_type, units='unitless'
-        )
+        add_aviary_input(self, Aircraft.Design.GROSS_MASS, units='lbm')
         add_aviary_input(
             self, Aircraft.Nacelle.CORE_DIAMETER_RATIO, shape=num_engine_type, units='unitless'
         )
@@ -190,125 +185,38 @@ def setup(self):
         add_aviary_output(self, Aircraft.Nacelle.SURFACE_AREA, shape=num_engine_type, units='ft**2')
 
     def setup_partials(self):
-        # derivatives w.r.t vectorized engine inputs have known sparsity pattern
         num_engine_type = len(self.options[Aircraft.Engine.NUM_ENGINES])
         shape = np.arange(num_engine_type)
-
-        innames = [
-            Aircraft.Engine.REFERENCE_DIAMETER,
-            Aircraft.Engine.SCALE_FACTOR,
-            Aircraft.Nacelle.CORE_DIAMETER_RATIO,
-            Aircraft.Nacelle.FINENESS,
-        ]
+        nn = np.zeros(num_engine_type, dtype=int)
 
         self.declare_partials(
-            Aircraft.Nacelle.AVG_DIAMETER, innames[:-1], rows=shape, cols=shape, val=1.0
+            Aircraft.Nacelle.AVG_DIAMETER,
+            [
+                Aircraft.Design.GROSS_MASS,
+            ],
+            rows=shape,
+            cols=nn,
         )
-        self.declare_partials(Aircraft.Nacelle.AVG_LENGTH, innames, rows=shape, cols=shape, val=1.0)
         self.declare_partials(
-            Aircraft.Nacelle.SURFACE_AREA,
-            innames + ['percent_exposed'],
+            Aircraft.Nacelle.AVG_LENGTH,
+            [
+                Aircraft.Design.GROSS_MASS,
+            ],
             rows=shape,
-            cols=shape,
-            val=1.0,
-        )
-
-    def compute(self, inputs, outputs):
-        verbosity = self.options[Settings.VERBOSITY]
-        d_ref = inputs[Aircraft.Engine.REFERENCE_DIAMETER]
-        scale_fac = inputs[Aircraft.Engine.SCALE_FACTOR]
-        d_nac_eng = inputs[Aircraft.Nacelle.CORE_DIAMETER_RATIO]
-        ld_nac = inputs[Aircraft.Nacelle.FINENESS]
-        if any(x <= 0.0 for x in scale_fac):
-            if verbosity > Verbosity.BRIEF:
-                print('Aircraft.Engine.SCALE_FACTOR must be positive.')
-
-        d_eng = d_ref * np.sqrt(scale_fac)
-        outputs[Aircraft.Nacelle.AVG_DIAMETER] = d_eng * d_nac_eng
-        outputs[Aircraft.Nacelle.AVG_LENGTH] = ld_nac * outputs[Aircraft.Nacelle.AVG_DIAMETER]
-        outputs[Aircraft.Nacelle.SURFACE_AREA] = (
-            np.pi
-            * outputs[Aircraft.Nacelle.AVG_DIAMETER]
-            * outputs[Aircraft.Nacelle.AVG_LENGTH]
-            * inputs['percent_exposed']
-        )
-
-    def compute_partials(self, inputs, J):
-        d_ref = inputs[Aircraft.Engine.REFERENCE_DIAMETER]
-        scale_fac = inputs[Aircraft.Engine.SCALE_FACTOR]
-        d_nac_eng = inputs[Aircraft.Nacelle.CORE_DIAMETER_RATIO]
-        ld_nac = inputs[Aircraft.Nacelle.FINENESS]
-
-        tr = np.sqrt(scale_fac)
-        d_eng = d_ref * tr
-        d_nac = d_eng * d_nac_eng
-        l_nac = d_nac * ld_nac
-
-        J[Aircraft.Nacelle.AVG_DIAMETER, Aircraft.Engine.REFERENCE_DIAMETER] = tr * d_nac_eng
-        J[Aircraft.Nacelle.AVG_DIAMETER, Aircraft.Engine.SCALE_FACTOR] = (
-            d_nac_eng * d_ref / (2 * tr)
+            cols=nn,
         )
-        J[Aircraft.Nacelle.AVG_DIAMETER, Aircraft.Nacelle.CORE_DIAMETER_RATIO] = d_eng
-
-        for wrt in [
-            Aircraft.Engine.REFERENCE_DIAMETER,
-            Aircraft.Engine.SCALE_FACTOR,
-            Aircraft.Nacelle.CORE_DIAMETER_RATIO,
-        ]:
-            J[Aircraft.Nacelle.AVG_LENGTH, wrt] = J[Aircraft.Nacelle.AVG_DIAMETER, wrt] * ld_nac
-            J[Aircraft.Nacelle.SURFACE_AREA, wrt] = (
-                np.pi
-                * (
-                    J[Aircraft.Nacelle.AVG_DIAMETER, wrt] * l_nac
-                    + J[Aircraft.Nacelle.AVG_LENGTH, wrt] * d_nac
-                )
-                * inputs['percent_exposed']
-            )
-
-        J[Aircraft.Nacelle.AVG_LENGTH, Aircraft.Nacelle.FINENESS] = d_nac
-        J[Aircraft.Nacelle.SURFACE_AREA, Aircraft.Nacelle.FINENESS] = (
-            np.pi
-            * J[Aircraft.Nacelle.AVG_LENGTH, Aircraft.Nacelle.FINENESS]
-            * d_nac
-            * inputs['percent_exposed']
-        )
-        J[Aircraft.Nacelle.SURFACE_AREA, 'percent_exposed'] = (
-            np.pi * d_eng * d_nac_eng * ld_nac * d_eng * d_nac_eng
-        )
-
-
-class BWBEngineSize(om.ExplicitComponent):
-    """
-    Engine geometry calculation for BWB. It returns Aircraft.Nacelle.AVG_DIAMETER,
-    Nacelle.AVG_LENGTH, and Aircraft.Nacelle.SURFACE_AREA. It follows the algorithm in GASP.
-    Users can use this component instead of EngineSize.
-    """
-
-    def initialize(self):
-        add_aviary_option(self, Aircraft.Engine.NUM_ENGINES)
-        add_aviary_option(self, Settings.VERBOSITY)
-
-    def setup(self):
-        num_engine_type = len(self.options[Aircraft.Engine.NUM_ENGINES])
-
-        add_aviary_input(self, Aircraft.Design.GROSS_MASS, units='lbm')
-        add_aviary_input(
-            self, Aircraft.Nacelle.CORE_DIAMETER_RATIO, shape=num_engine_type, units='unitless'
+        self.declare_partials(
+            Aircraft.Nacelle.SURFACE_AREA,
+            [
+                Aircraft.Design.GROSS_MASS,
+            ],
+            rows=shape,
+            cols=nn,
         )
-        add_aviary_input(self, Aircraft.Nacelle.FINENESS, shape=num_engine_type, units='unitless')
-        self.add_input('percent_exposed', val=np.ones(num_engine_type), units='unitless')
-
-        add_aviary_output(self, Aircraft.Nacelle.AVG_DIAMETER, shape=num_engine_type, units='ft')
-        add_aviary_output(self, Aircraft.Nacelle.AVG_LENGTH, shape=num_engine_type, units='ft')
-        add_aviary_output(self, Aircraft.Nacelle.SURFACE_AREA, shape=num_engine_type, units='ft**2')
 
-    def setup_partials(self):
-        num_engine_type = len(self.options[Aircraft.Engine.NUM_ENGINES])
-        shape = np.arange(num_engine_type)
         self.declare_partials(
             Aircraft.Nacelle.AVG_DIAMETER,
             [
-                Aircraft.Design.GROSS_MASS,
                 Aircraft.Nacelle.CORE_DIAMETER_RATIO,
             ],
             rows=shape,
@@ -317,7 +225,6 @@ def setup_partials(self):
         self.declare_partials(
             Aircraft.Nacelle.AVG_LENGTH,
             [
-                Aircraft.Design.GROSS_MASS,
                 Aircraft.Nacelle.CORE_DIAMETER_RATIO,
                 Aircraft.Nacelle.FINENESS,
             ],
@@ -327,7 +234,6 @@ def setup_partials(self):
         self.declare_partials(
             Aircraft.Nacelle.SURFACE_AREA,
             [
-                Aircraft.Design.GROSS_MASS,
                 Aircraft.Nacelle.CORE_DIAMETER_RATIO,
                 Aircraft.Nacelle.FINENESS,
                 'percent_exposed',
@@ -337,15 +243,15 @@ def setup_partials(self):
         )
 
     def compute(self, inputs, outputs):
-        verbosity = self.options[Settings.VERBOSITY]
         num_engine = self.options[Aircraft.Engine.NUM_ENGINES]
+        coeff_inlet = self.options[Aircraft.Engine.INLET_AREA_COEFFICIENT]
 
         gross_mass = inputs[Aircraft.Design.GROSS_MASS]
         core_diam_ratio = inputs[Aircraft.Nacelle.CORE_DIAMETER_RATIO]
         fineness_nac = inputs[Aircraft.Nacelle.FINENESS]
         pct_exposed = inputs['percent_exposed']
 
-        area_engine = 0.3 * gross_mass / 1500.0 / num_engine
+        area_engine = coeff_inlet * gross_mass / num_engine
         diam_engine = np.sqrt(4.0 * area_engine / np.pi)
         diam_nacelle = core_diam_ratio * diam_engine
         len_nacelle = fineness_nac * diam_nacelle
@@ -357,19 +263,20 @@ def compute(self, inputs, outputs):
 
     def compute_partials(self, inputs, J):
         num_engine = self.options[Aircraft.Engine.NUM_ENGINES]
+        coeff_inlet = self.options[Aircraft.Engine.INLET_AREA_COEFFICIENT]
 
         gross_mass = inputs[Aircraft.Design.GROSS_MASS]
+        gross_mass = np.full(len(num_engine), gross_mass)
         core_diam_ratio = inputs[Aircraft.Nacelle.CORE_DIAMETER_RATIO]
         fineness_nac = inputs[Aircraft.Nacelle.FINENESS]
         pct_exposed = inputs['percent_exposed']
 
-        area_engine = 0.3 * gross_mass / 1500.0 / num_engine
+        area_engine = coeff_inlet * gross_mass / num_engine
         diam_engine = np.sqrt(4.0 * area_engine / np.pi)
         diam_nacelle = core_diam_ratio * diam_engine
         len_nacelle = fineness_nac * diam_nacelle
-        wet_area_nacelle = np.pi * diam_nacelle * len_nacelle * pct_exposed
 
-        darea_engine_dgross_mass = 0.3 * np.ones(1) / 1500.0 / num_engine
+        darea_engine_dgross_mass = coeff_inlet * np.ones(1) / num_engine
         ddiam_engine_dgross_mass = 2 / np.pi / diam_engine * darea_engine_dgross_mass
         ddiam_nacelle_dgross_mass = core_diam_ratio * ddiam_engine_dgross_mass
         ddiam_nacelle_dcore_diam_ratio = diam_engine
@@ -412,7 +319,7 @@ def compute_partials(self, inputs, J):
         J[Aircraft.Nacelle.SURFACE_AREA, 'percent_exposed'] = dwet_area_nacelle_dpct_exposed
 
 
-class BWBEngineSizeGroup(om.Group):
+class GASPEngineSizeGroup(om.Group):
     def setup(self):
         self.add_subsystem(
             'perc',
@@ -423,7 +330,7 @@ def setup(self):
 
         self.add_subsystem(
             'eng_size',
-            BWBEngineSize(),
+            GASPEngineSize(),
             promotes_inputs=['*'] + ['percent_exposed'],
             promotes_outputs=['*'],
         )