[Draft] Add a Few Drag Factors and Aero Technology Factors

aviary/subsystems/aerodynamics/gasp_based/gaspaero.py

@@ -372,7 +372,9 @@ def compute(self, inputs, outputs):
 
         delta = (static_margin + delta_cg) * h_tail_moment
 
-        # TODO handle xt < 0?
+        if h_tail_moment.real < 0.0:
+            if verbosity > Verbosity.BRIEF:
+                warnings.warn(f'Aircraft.HorizontalTail.MOMENT_RATIO is {h_tail_moment}.')
         xt = 1 / h_tail_moment
 
         art = AR * bbar**2 / sbar
@@ -740,6 +742,24 @@ def initialize(self):
         self.options.declare('num_nodes', default=1, types=int)
         add_aviary_option(self, Aircraft.Engine.NUM_ENGINES)
         add_aviary_option(self, Aircraft.Wing.HAS_STRUT)
+        # drag factors
+        add_aviary_option(self, Aircraft.Design.HorizontalTail_DRAG_FACTOR)
+        add_aviary_option(self, Aircraft.Design.INTERFERENCE_DRAG_FACTOR)
+        add_aviary_option(self, Aircraft.Design.Nacelle_DRAG_FACTOR)
+        add_aviary_option(self, Aircraft.Design.PYLON_DRAG_FACTOR)
+        add_aviary_option(self, Aircraft.Design.STRUT_DRAG_FACTOR)
+        add_aviary_option(self, Aircraft.Design.VerticalTail_DRAG_FACTOR)
+        add_aviary_option(self, Aircraft.Design.Wing_DRAG_FACTOR)
+        add_aviary_option(self, Aircraft.Design.EXCRESCENCE_DRAG_FACTOR)
+        add_aviary_option(self, Aircraft.Design.PERCENT_EXCRESCENCE_DRAG)
+        # aero technology factos
+        add_aviary_option(self, Aircraft.Design.Fuselage_AERO_TECH_FACTOR)
+        add_aviary_option(self, Aircraft.Design.HorizontalTail_AERO_TECH_FACTOR)
+        add_aviary_option(self, Aircraft.Design.INTERFERENCE_AERO_TECH_FACTOR)
+        add_aviary_option(self, Aircraft.Design.Nacelle_AERO_TECH_FACTOR)
+        add_aviary_option(self, Aircraft.Design.STRUT_AERO_TECH_FACTOR)
+        add_aviary_option(self, Aircraft.Design.VerticalTail_AERO_TECH_FACTOR)
+        add_aviary_option(self, Aircraft.Design.Wing_AERO_TECH_FACTOR)
 
     def setup(self):
         nn = self.options['num_nodes']
@@ -833,6 +853,26 @@ def setup(self):
             desc='SIWB: curve fitting correction factor for Oswald efficiency',
         )
 
+        # drag factors
+        add_aviary_input(self, Aircraft.Design.Fuselage_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.HorizontalTail_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.INTERFERENCE_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.Nacelle_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.PYLON_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.STRUT_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.VerticalTail_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.Wing_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.EXCRESCENCE_DRAG_FACTOR)
+        add_aviary_input(self, Aircraft.Design.PERCENT_EXCRESCENCE_DRAG)
+        # aero technology factos
+        add_aviary_input(self, Aircraft.Design.Fuselage_AERO_TECH_FACTOR)
+        add_aviary_input(self, Aircraft.Design.HorizontalTail_AERO_TECH_FACTOR)
+        add_aviary_input(self, Aircraft.Design.INTERFERENCE_AERO_TECH_FACTOR)
+        add_aviary_input(self, Aircraft.Design.Nacelle_AERO_TECH_FACTOR)
+        add_aviary_input(self, Aircraft.Design.STRUT_AERO_TECH_FACTOR)
+        add_aviary_input(self, Aircraft.Design.VerticalTail_AERO_TECH_FACTOR)
+        add_aviary_input(self, Aircraft.Design.Wing_AERO_TECH_FACTOR)
+
         # outputs
         self.add_output('SA1', units='unitless', shape=nn, desc='SA1: drag param')
         self.add_output('SA2', units='unitless', shape=nn, desc='SA2: drag param')
@@ -998,9 +1038,32 @@ def compute(self, inputs, outputs):
             feintwf,
             areashieldwf,
             siwb,
+            fcffc,
+            fcfhtc,
+            fckic,
+            fcfnc,
+            fpylnd,
+            fcfstrc,
+            fcfvtc,
+            fcfwc,
+            fexcrt,
+            pct_excr,
+            fcfft,
+            fcfhtt,
+            fckit,
+            fcfnt,
+            fcfstrt,
+            fcfvtt,
+            fcfwt,
         ) = inputs.values()
         # skin friction coeff at Re = 10**7
         cf = 0.455 / 7**2.58 / (1 + 0.144 * mach**2) ** 0.65
+        cdfi = fcffc * fcfft * cf
+        cdhti = fcfhtc * fcfhtt * cf
+        cdni = fcfnc * fcfnt * cf
+        cdstrti = fcfstrc * fcfstrt * cf 
+        cdvti = fcfvtc * fcfvtt * cf
+        cdwi = fcfwc * fcfwt * cf
 
         t = cs.abs(np.tan(deg2rad(sweep_c4)))
         yale05 = (1 - taper_ratio) / (1 + taper_ratio)
@@ -1046,28 +1109,30 @@ def compute(self, inputs, outputs):
 
         # flat plate equivalent areas
         # GASP uses different values of cf for wing, nacelle, fuselage, etc.
-        fef = fus_SA * cf * ffre * ff_fus + fe_fus_inc
-        few = ff_wing * wing_area * cf * fwre
-        # TODO replace 2 with num_engines
-        fen = 2 * ff_nac * nacelle_area * cf * fnre
-        fevt = ff_vtail * vtail_area * cf * fvtre
-        feht = ff_htail * htail_area * cf * fhtre
-        festrt = strut_fus_intf * strut_wing_area_ratio * wing_area * cf * fstrtre
+        fef = fus_SA * cdfi * ffre * ff_fus + fe_fus_inc
+        few = ff_wing * wing_area * cdwi * fwre
+        # Replaced 2 with total_num_engines. Need to check. See issue #1080
+        total_num_engines = sum(self.options[Aircraft.Engine.NUM_ENGINES])
+        fen = fpylnd * total_num_engines * ff_nac * nacelle_area * cdni * fnre
+        fevt = ff_vtail * vtail_area * cdvti * fvtre
+        feht = ff_htail * htail_area * cdhti * fhtre
+        festrt = strut_fus_intf * strut_wing_area_ratio * wing_area * cdstrti * fstrtre
 
         # begin INTERFERENCE - get flat plate equivalent for wing-fuselage interference
         # wing profile drag coefficient
         cdw0 = few / wing_area
         # interference drag independent of shielded area
         feshieldwf = cdw0 * areashieldwf
-        feiwf = wing_fus_intf * (feintwf - feshieldwf)
+        feiwf = fckic * fckit * (wing_fus_intf * (feintwf - feshieldwf))
         # end INTERFERENCE
 
-        # total flat plate equivalent area
-        # In GASP, nacelle is excluded.
-        fe = few + fef + fevt + feht + fen + feiwf + festrt + cd0_inc * wing_area
+        # Excrescence Drag
+        feexcr = fexcrt * pct_excr * (few + fef + fevt + feht + fen + festrt)
 
-        # wfob = cabin_width / wingspan
-        # siwb = 1 - 0.0088 * wfob - 1.7364 * wfob**2 - 2.303 * wfob**3 + 6.0606 * wfob**4
+        # total flat plate equivalent area
+        # In GASP, nacelle is excluded. It's kept here because nacelle dimension is 
+        # done in premission and hence does not size.
+        fe = few + fef + fevt + feht + fen + feiwf + festrt + cd0_inc * wing_area + feexcr
 
         # wing-free profile drag coefficient
         cdpo = (fe - few) / wing_area
@@ -1404,6 +1469,8 @@ def setup(self):
         add_aviary_input(self, Aircraft.Design.SUPERSONIC_DRAG_COEFF_FACTOR, units='unitless')
         add_aviary_input(self, Aircraft.Design.LIFT_DEPENDENT_DRAG_COEFF_FACTOR, units='unitless')
         add_aviary_input(self, Aircraft.Design.ZERO_LIFT_DRAG_COEFF_FACTOR, units='unitless')
+        add_aviary_input(self, Aircraft.Design.INDUCED_DRAG_FACTOR, units='unitless')
+        add_aviary_input(self, Aircraft.Design.COMPRESSIBILITY_DRAG_FACTOR, units='unitless')
 
         # from aero setup
         self.add_input(
@@ -1430,7 +1497,15 @@ def setup_partials(self):
             cols=ar,
             method='cs',
         )
-        self.declare_partials('CD', [Aircraft.Design.DRAG_DIVERGENCE_SHIFT], method='cs')
+        self.declare_partials(
+            'CD',
+            [
+                Aircraft.Design.DRAG_DIVERGENCE_SHIFT,
+                Aircraft.Design.INDUCED_DRAG_FACTOR,
+                Aircraft.Design.COMPRESSIBILITY_DRAG_FACTOR,
+            ],
+            method='cs',
+        )
 
     def compute(self, inputs, outputs):
         (
@@ -1441,6 +1516,8 @@ def compute(self, inputs, outputs):
             supersonic_factor,
             lift_factor,
             zero_lift_factor,
+            fsa7c,
+            fcmpc,
             cf,
             SA1,
             SA2,
@@ -1461,9 +1538,9 @@ def compute(self, inputs, outputs):
         # profile drag
         cd0 = SA5 + SA6 * cf
         # induced drag
-        cdi = SA7 * CL**2
+        cdi = fsa7c * SA7 * CL**2
 
-        CD = cd0 * zero_lift_factor + cdi * lift_factor + delcdm
+        CD = cd0 * zero_lift_factor + cdi * lift_factor + fcmpc * delcdm
 
         # scale drag
         idx_sup = np.where(mach >= 1.0)

aviary/subsystems/aerodynamics/gasp_based/interference.py

@@ -325,6 +325,7 @@ def setup(self):
         )
 
 
+# This component is not used
 class WingFuselageInterferenceMission(om.ExplicitComponent):
     """
     This calculates an additional flat plate drag area due to general aerodynamic interference for wing-fuselage interference

aviary/utils/test/data/converter_test_BWB_GASP.csv

@@ -25,18 +25,36 @@ aircraft:crew_and_payload:uld_mass_per_passenger,0.0667,lbm
 aircraft:crew_and_payload:water_mass_per_occupant,3.0,lbm
 aircraft:design:cg_delta,0.25,unitless
 aircraft:design:cockpit_control_mass_coefficient,16.5,unitless
+aircraft:design:compressibility_drag_factor,1.0,unitless
 aircraft:design:cruise_altitude,41000.0,ft
 aircraft:design:drag_coefficient_increment,0.00025,unitless
 aircraft:design:drag_divergence_shift,0.025,unitless
 aircraft:design:emergency_equipment_mass,100.0,lbm
+aircraft:design:excrescence_drag_factor,0.8,unitless
+aircraft:design:fuselage_aero_tech_factor,0.93,unitless
+aircraft:design:fuselage_drag_factor,0.885,unitless
 aircraft:design:gross_mass,150000.0,lbm
+aircraft:design:horizontaltail_aero_tech_factor,0.926,unitless
+aircraft:design:horizontaltail_drag_factor,0.75,unitless
+aircraft:design:induced_drag_factor,0.85,unitless
+aircraft:design:interference_aero_tech_factor,1.0,unitless
+aircraft:design:interference_drag_factor,1.0,unitless
 aircraft:design:mach,0.8,unitless
 aircraft:design:max_structural_speed,402.5,mi/h
+aircraft:design:nacelle_aero_tech_factor,0.95,unitless
+aircraft:design:nacelle_drag_factor,1.15,unitless
 aircraft:design:part25_structural_category,3.0,unitless
+aircraft:design:pylon_drag_factor,1.15,unitless
 aircraft:design:range,3500.0,NM
 aircraft:design:static_margin,0.05,unitless
 aircraft:design:structural_mass_increment,0.0,lbm
+aircraft:design:strut_aero_tech_factor,0.926,unitless
+aircraft:design:strut_drag_factor,0.9,unitless
 aircraft:design:type,BWB,unitless
+aircraft:design:verticaltail_aero_tech_factor,0.926,unitless
+aircraft:design:verticaltail_drag_factor,0.9,unitless
+aircraft:design:wing_aero_tech_factor,0.926,unitless
+aircraft:design:wing_drag_factor,0.906,unitless
 aircraft:design:wing_loading,70.0,lbf/ft**2
 aircraft:electrical:system_mass_per_passenger,11.45,lbm
 aircraft:engine:additional_mass_fraction,0.04373,unitless
@@ -190,23 +208,7 @@ INGASP.DCDSE,0.001
 INGASP.DYR,12
 INGASP.EL_FLGC,8
 INGASP.EMCRU,0.8
-INGASP.FCFFC,0.885
-INGASP.FCFFT,0.93
-INGASP.FCFHTC,0.75
-INGASP.FCFHTT,0.926
-INGASP.FCFNC,1.15
-INGASP.FCFNT,0.95
-INGASP.FCFVTC,0.9
-INGASP.FCFVTT,0.926
-INGASP.FCFWC,0.906
-INGASP.FCFWT,0.926
-INGASP.FCKIC,1
-INGASP.FCKIT,1
-INGASP.FCMPC,1
 INGASP.FCSF,2.5
-INGASP.FEXCRT,0.8
-INGASP.FPYLND,1.15
-INGASP.FSA7C,0.85
 INGASP.HBTP,0.465
 INGASP.HIR,0.015
 INGASP.HNCRU,41000

aviary/utils/test/data/converter_test_large_single_aisle_1_GASP.csv

@@ -30,6 +30,7 @@ aircraft:design:gross_mass,175400.0,lbm
 aircraft:design:mach,0.8,unitless
 aircraft:design:max_structural_speed,402.5,mi/h
 aircraft:design:part25_structural_category,3.0,unitless
+aircraft:design:pylon_drag_factor,1.0,unitless
 aircraft:design:range,3675.0,NM
 aircraft:design:static_margin,0.03,unitless
 aircraft:design:structural_mass_increment,0.0,lbm
@@ -182,7 +183,6 @@ INGASP.DCDSE,-1
 INGASP.DYR,12
 INGASP.EMCRU,0.8
 INGASP.FCSF,2.5
-INGASP.FPYLND,1
 INGASP.HBTP,0.333
 INGASP.HIR,0.015
 INGASP.HNCRU,37500