def main(): #only do calculation for 747 from Boeing_747 import vehicle_setup, configs_setup vehicle = vehicle_setup() configs = configs_setup(vehicle) Mach = np.array([0.198]) segment = SUAVE.Analyses.Mission.Segments.Segment() segment.freestream = Data() segment.freestream.mach_number = Mach segment.atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976() altitude = 0.0 * Units.feet conditions = segment.atmosphere.compute_values(altitude / Units.km) segment.a = conditions.speed_of_sound segment.freestream.density = conditions.density segment.freestream.dynamic_viscosity = conditions.dynamic_viscosity segment.freestream.velocity = segment.freestream.mach_number * segment.a #Method Test cn_b = taw_cnbeta(vehicle, segment, configs.base) expected = 0.09427599 # Should be 0.184 error = Data() error.cn_b_747 = (cn_b - expected) / expected print error for k, v in error.items(): assert (np.abs(v) < 0.1) return
def main(): #only do calculation for 747 from Boeing_747 import vehicle_setup, configs_setup vehicle = vehicle_setup() configs = configs_setup(vehicle) Mach = np.array([0.198]) segment = SUAVE.Analyses.Mission.Segments.Segment() segment.freestream = Data() segment.freestream.mach_number = Mach segment.atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976() altitude = 0.0 * Units.feet conditions = segment.atmosphere.compute_values(altitude / Units.km) segment.a = conditions.speed_of_sound segment.freestream.density = conditions.density segment.freestream.dynamic_viscosity = conditions.dynamic_viscosity segment.freestream.velocity = segment.freestream.mach_number * segment.a #Method Test cn_b = taw_cnbeta(vehicle,segment,configs.base) expected = 0.09427599 # Should be 0.184 error = Data() error.cn_b_747 = (cn_b-expected)/expected print(error) for k,v in list(error.items()): assert(np.abs(v)<1e-6) return
def main(): #Parameters Required #Using values for a Boeing 747-200 vehicle = SUAVE.Vehicle() wing = SUAVE.Components.Wings.Wing() wing.tag = 'main_wing' wing.areas.reference = 5500.0 * Units.feet**2 wing.spans.projected = 196.0 * Units.feet wing.sweep = 42.0 * Units.deg # Leading edge wing.chords.root = 42.9 * Units.feet #54.5 wing.chords.tip = 14.7 * Units.feet wing.chords.mean_aerodynamic = 27.3 * Units.feet wing.taper = wing.chords.tip / wing.chords.root wing.aspect_ratio = wing.spans.projected**2/wing.areas.reference wing.symmetric = True wing.origin = np.array([58.6,0.,3.6]) * Units.feet reference = SUAVE.Core.Container() vehicle.reference_area = wing.areas.reference vehicle.append_component(wing) wing = SUAVE.Components.Wings.Wing() wing.tag = 'vertical_stabilizer' vertical = SUAVE.Components.Wings.Wing() vertical.spans.exposed = 32.4 * Units.feet vertical.chords.root = 38.7 * Units.feet # vertical.chords.fuselage_intersect vertical.chords.tip = 13.4 * Units.feet vertical.sweep = 50.0 * Units.deg # Leading Edge vertical.x_root_LE1 = 180.0 * Units.feet vertical.symmetric = False vertical.exposed_root_chord_offset = 13.3 * Units.feet ref_vertical = extend_to_ref_area(vertical) wing.areas.reference = ref_vertical.areas.reference wing.spans.projected = ref_vertical.spans.projected wing.chords.root = ref_vertical.chords.root dx_LE_vert = ref_vertical.root_LE_change wing.chords.tip = vertical.chords.tip wing.aspect_ratio = ref_vertical.aspect_ratio wing.sweep = vertical.sweep wing.taper = wing.chords.tip/wing.chords.root wing.origin = np.array([vertical.x_root_LE1 + dx_LE_vert,0.,0.]) wing.effective_aspect_ratio = 2.2 wing.symmetric = False wing.aerodynamic_center = np.array([trapezoid_ac_x(wing),0.0,0.0]) Mach = np.array([0.198]) wing.CL_alpha = datcom(wing,Mach) vehicle.append_component(wing) fuselage = SUAVE.Components.Fuselages.Fuselage() fuselage.tag = 'fuselage' fuselage.areas.side_projected = 4696.16 * Units.feet**2 fuselage.lengths.total = 229.7 * Units.feet fuselage.heights.maximum = 26.9 * Units.feet fuselage.width = 20.9 * Units.feet fuselage.heights.at_quarter_length = 26.0 * Units.feet fuselage.heights.at_three_quarters_length = 19.7 * Units.feet fuselage.heights.at_wing_root_quarter_chord = 23.8 * Units.feet vehicle.append_component(fuselage) configuration = Data() configuration.mass_properties = Data() configuration.mass_properties.center_of_gravity = Data() configuration.mass_properties.center_of_gravity = np.array([112.2,0,6.8]) * Units.feet #segment = SUAVE.Analyses.Mission.Segments.Base_Segment() segment = SUAVE.Analyses.Mission.Segments.Segment() segment.freestream = Data() segment.freestream.mach_number = Mach[0] segment.atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976() altitude = 0.0 * Units.feet conditions = segment.atmosphere.compute_values(altitude / Units.km) segment.a = conditions.speed_of_sound segment.freestream.density = conditions.density segment.freestream.dynamic_viscosity = conditions.dynamic_viscosity segment.freestream.velocity = segment.freestream.mach_number * segment.a #Method Test cn_b = taw_cnbeta(vehicle,segment,configuration) expected = 0.10045 # Should be 0.184 error = Data() error.cn_b_747 = (cn_b-expected)/expected #Parameters Required #Using values for a Beechcraft Model 99 #MODEL DOES NOT ACCOUNT FOR DESTABILIZING EFFECTS OF PROPELLERS! """wing = SUAVE.Components.Wings.Wing() wing.area = 280.0 * Units.feet**2 wing.span = 46.0 * Units.feet wing.sweep_le = 3.0 * Units.deg wing.z_position = 2.2 * Units.feet wing.taper = 0.46 wing.aspect_ratio = wing.span**2/wing.area wing.symmetric = True fuselage = SUAVE.Components.Fuselages.Fuselage() fuselage.side_area = 185.36 * Units.feet**2 fuselage.length = 44.0 * Units.feet fuselage.h_max = 6.0 * Units.feet fuselage.w_max = 5.4 * Units.feet fuselage.height_at_vroot_quarter_chord = 2.9 * Units.feet fuselage.height_at_quarter_length = 4.8 * Units.feet fuselage.height_at_three_quarters_length = 4.3 * Units.feet nacelle = SUAVE.Components.Fuselages.Fuselage() nacelle.side_area = 34.45 * Units.feet**2 nacelle.x_front = 7.33 * Units.feet nacelle.length = 14.13 * Units.feet nacelle.h_max = 3.68 * Units.feet nacelle.w_max = 2.39 * Units.feet nacelle.height_at_quarter_length = 3.08 * Units.feet nacelle.height_at_three_quarters_length = 2.12 * Units.feet other_bodies = [nacelle,nacelle] vertical = SUAVE.Components.Wings.Wing() vertical.span = 6.6 * Units.feet vertical.root_chord = 8.2 * Units.feet vertical.tip_chord = 3.6 * Units.feet vertical.sweep_le = 47.0 * Units.deg vertical.x_root_LE1 = 34.8 * Units.feet vertical.symmetric = False dz_centerline = 2.0 * Units.feet ref_vertical = extend_to_ref_area(vertical,dz_centerline) vertical.span = ref_vertical.ref_span vertical.area = ref_vertical.ref_area vertical.aspect_ratio = ref_vertical.ref_aspect_ratio vertical.x_root_LE = vertical.x_root_LE1 + ref_vertical.root_LE_change vertical.taper = vertical.tip_chord/ref_vertical.ref_root_chord vertical.effective_aspect_ratio = 1.57 vertical.x_ac_LE = trapezoid_ac_x(vertical) aircraft = SUAVE.Vehicle() aircraft.wing = wing aircraft.fuselage = fuselage aircraft.other_bodies = other_bodies aircraft.vertical = vertical aircraft.Mass_Props.pos_cg[0] = 17.2 * Units.feet segment = SUAVE.Analyses.Mission.Segments.Base_Segment() segment.M = 0.152 segment.atmosphere = SUAVE.Attributes.Atmospheres.Earth.US_Standard_1976() altitude = 0.0 * Units.feet segment.a = segment.atmosphere.compute_values(altitude / Units.km, type="a") segment.rho = segment.atmosphere.compute_values(altitude / Units.km, type="rho") segment.mew = segment.atmosphere.compute_values(altitude / Units.km, type="mew") segment.v_inf = segment.M * segment.a #Method Test expected = 0.12 print 'Beech 99 at M = {0} and h = {1} meters'.format(segment.M, altitude) cn_b = taw_cnbeta(aircraft,segment) print 'Cn_beta = {0:.4f}'.format(cn_b) print 'Expected value = {}'.format(expected) print 'Percent Error = {0:.2f}%'.format(100.0*(cn_b-expected)/expected) print ' ' #Parameters Required #Using values for an SIAI Marchetti S-211 wing = SUAVE.Components.Wings.Wing() wing.area = 136.0 * Units.feet**2 wing.span = 26.3 * Units.feet wing.sweep_le = 19.5 * Units.deg wing.z_position = -1.1 * Units.feet wing.taper = 3.1/7.03 wing.aspect_ratio = wing.span**2/wing.area fuselage = SUAVE.Components.Fuselages.Fuselage() fuselage.side_area = 116.009 * Units.feet**2 fuselage.length = 30.9 * Units.feet fuselage.h_max = 5.1 * Units.feet fuselage.w_max = 5.9 * Units.feet fuselage.height_at_vroot_quarter_chord = 4.1 * Units.feet fuselage.height_at_quarter_length = 4.5 * Units.feet fuselage.height_at_three_quarters_length = 4.3 * Units.feet other_bodies = [] vertical = SUAVE.Components.Wings.Wing() vertical.span = 5.8 * Units.feet vertical.root_chord = 5.7 * Units.feet vertical.tip_chord = 2.0 * Units.feet vertical.sweep_le = 40.2 * Units.deg vertical.x_root_LE1 = 22.62 * Units.feet vertical.symmetric = False dz_centerline = 2.9 * Units.feet ref_vertical = extend_to_ref_area(vertical,dz_centerline) vertical.span = ref_vertical.ref_span vertical.area = ref_vertical.ref_area vertical.aspect_ratio = ref_vertical.ref_aspect_ratio vertical.x_root_LE = vertical.x_root_LE1 + ref_vertical.root_LE_change vertical.taper = vertical.tip_chord/ref_vertical.ref_root_chord vertical.effective_aspect_ratio = 2.65 vertical.x_ac_LE = trapezoid_ac_x(vertical) aircraft = SUAVE.Vehicle() aircraft.wing = wing aircraft.fuselage = fuselage aircraft.other_bodies = other_bodies aircraft.vertical = vertical aircraft.Mass_Props.pos_cg[0] = 16.6 * Units.feet segment = SUAVE.Analyses.Mission.Segments.Base_Segment() segment.M = 0.111 segment.atmosphere = SUAVE.Attributes.Atmospheres.Earth.US_Standard_1976() altitude = 0.0 * Units.feet segment.a = segment.atmosphere.compute_values(altitude / Units.km, type="a") segment.rho = segment.atmosphere.compute_values(altitude / Units.km, type="rho") segment.mew = segment.atmosphere.compute_values(altitude / Units.km, type="mew") segment.v_inf = segment.M * segment.a #Method Test print 'SIAI Marchetti S-211 at M = {0} and h = {1} meters'.format(segment.M, altitude) cn_b = taw_cnbeta(aircraft,segment) expected = 0.160 print 'Cn_beta = {0:.4f}'.format(cn_b) print 'Expected value = {}'.format(expected) print 'Percent Error = {0:.2f}%'.format(100.0*(cn_b-expected)/expected) print ' '""" for k,v in error.items(): assert(np.abs(v)<0.1) return
def main(): #Parameters Required #Using values for a Boeing 747-200 vehicle = SUAVE.Vehicle() wing = SUAVE.Components.Wings.Wing() wing.tag = 'main_wing' wing.areas.reference = 5500.0 * Units.feet**2 wing.spans.projected = 196.0 * Units.feet wing.sweep = 42.0 * Units.deg # Leading edge wing.chords.root = 42.9 * Units.feet #54.5 wing.chords.tip = 14.7 * Units.feet wing.chords.mean_aerodynamic = 27.3 * Units.feet wing.taper = wing.chords.tip / wing.chords.root wing.aspect_ratio = wing.spans.projected**2 / wing.areas.reference wing.symmetric = True wing.origin = np.array([58.6, 0., 3.6]) * Units.feet reference = SUAVE.Core.Container() vehicle.reference_area = wing.areas.reference vehicle.append_component(wing) wing = SUAVE.Components.Wings.Wing() wing.tag = 'vertical_stabilizer' vertical = SUAVE.Components.Wings.Wing() vertical.spans.exposed = 32.4 * Units.feet vertical.chords.root = 38.7 * Units.feet # vertical.chords.fuselage_intersect vertical.chords.tip = 13.4 * Units.feet vertical.sweep = 50.0 * Units.deg # Leading Edge vertical.x_root_LE1 = 180.0 * Units.feet vertical.symmetric = False vertical.exposed_root_chord_offset = 13.3 * Units.feet ref_vertical = extend_to_ref_area(vertical) wing.areas.reference = ref_vertical.areas.reference wing.spans.projected = ref_vertical.spans.projected wing.chords.root = ref_vertical.chords.root dx_LE_vert = ref_vertical.root_LE_change wing.chords.tip = vertical.chords.tip wing.aspect_ratio = ref_vertical.aspect_ratio wing.sweep = vertical.sweep wing.taper = wing.chords.tip / wing.chords.root wing.origin = np.array([vertical.x_root_LE1 + dx_LE_vert, 0., 0.]) wing.effective_aspect_ratio = 2.2 wing.symmetric = False wing.aerodynamic_center = np.array([trapezoid_ac_x(wing), 0.0, 0.0]) Mach = np.array([0.198]) wing.CL_alpha = datcom(wing, Mach) vehicle.append_component(wing) fuselage = SUAVE.Components.Fuselages.Fuselage() fuselage.tag = 'fuselage' fuselage.areas.side_projected = 4696.16 * Units.feet**2 fuselage.lengths.total = 229.7 * Units.feet fuselage.heights.maximum = 26.9 * Units.feet fuselage.width = 20.9 * Units.feet fuselage.heights.at_quarter_length = 26.0 * Units.feet fuselage.heights.at_three_quarters_length = 19.7 * Units.feet fuselage.heights.at_wing_root_quarter_chord = 23.8 * Units.feet vehicle.append_component(fuselage) configuration = Data() configuration.mass_properties = Data() configuration.mass_properties.center_of_gravity = Data() configuration.mass_properties.center_of_gravity = np.array([112.2, 0, 6.8 ]) * Units.feet #segment = SUAVE.Analyses.Mission.Segments.Base_Segment() segment = SUAVE.Analyses.Mission.Segments.Segment() segment.freestream = Data() segment.freestream.mach_number = Mach segment.atmosphere = SUAVE.Analyses.Atmospheric.US_Standard_1976() altitude = 0.0 * Units.feet conditions = segment.atmosphere.compute_values(altitude / Units.km) segment.a = conditions.speed_of_sound segment.freestream.density = conditions.density segment.freestream.dynamic_viscosity = conditions.dynamic_viscosity segment.freestream.velocity = segment.freestream.mach_number * segment.a #Method Test cn_b = taw_cnbeta(vehicle, segment, configuration) expected = 0.08122837 # Should be 0.184 error = Data() error.cn_b_747 = (cn_b - expected) / expected #Parameters Required #Using values for a Beechcraft Model 99 #MODEL DOES NOT ACCOUNT FOR DESTABILIZING EFFECTS OF PROPELLERS! """wing = SUAVE.Components.Wings.Wing() wing.area = 280.0 * Units.feet**2 wing.span = 46.0 * Units.feet wing.sweep_le = 3.0 * Units.deg wing.z_position = 2.2 * Units.feet wing.taper = 0.46 wing.aspect_ratio = wing.span**2/wing.area wing.symmetric = True fuselage = SUAVE.Components.Fuselages.Fuselage() fuselage.side_area = 185.36 * Units.feet**2 fuselage.length = 44.0 * Units.feet fuselage.h_max = 6.0 * Units.feet fuselage.w_max = 5.4 * Units.feet fuselage.height_at_vroot_quarter_chord = 2.9 * Units.feet fuselage.height_at_quarter_length = 4.8 * Units.feet fuselage.height_at_three_quarters_length = 4.3 * Units.feet nacelle = SUAVE.Components.Fuselages.Fuselage() nacelle.side_area = 34.45 * Units.feet**2 nacelle.x_front = 7.33 * Units.feet nacelle.length = 14.13 * Units.feet nacelle.h_max = 3.68 * Units.feet nacelle.w_max = 2.39 * Units.feet nacelle.height_at_quarter_length = 3.08 * Units.feet nacelle.height_at_three_quarters_length = 2.12 * Units.feet other_bodies = [nacelle,nacelle] vertical = SUAVE.Components.Wings.Wing() vertical.span = 6.6 * Units.feet vertical.root_chord = 8.2 * Units.feet vertical.tip_chord = 3.6 * Units.feet vertical.sweep_le = 47.0 * Units.deg vertical.x_root_LE1 = 34.8 * Units.feet vertical.symmetric = False dz_centerline = 2.0 * Units.feet ref_vertical = extend_to_ref_area(vertical,dz_centerline) vertical.span = ref_vertical.ref_span vertical.area = ref_vertical.ref_area vertical.aspect_ratio = ref_vertical.ref_aspect_ratio vertical.x_root_LE = vertical.x_root_LE1 + ref_vertical.root_LE_change vertical.taper = vertical.tip_chord/ref_vertical.ref_root_chord vertical.effective_aspect_ratio = 1.57 vertical.x_ac_LE = trapezoid_ac_x(vertical) aircraft = SUAVE.Vehicle() aircraft.wing = wing aircraft.fuselage = fuselage aircraft.other_bodies = other_bodies aircraft.vertical = vertical aircraft.Mass_Props.pos_cg[0] = 17.2 * Units.feet segment = SUAVE.Analyses.Mission.Segments.Base_Segment() segment.M = 0.152 segment.atmosphere = SUAVE.Attributes.Atmospheres.Earth.US_Standard_1976() altitude = 0.0 * Units.feet segment.a = segment.atmosphere.compute_values(altitude / Units.km, type="a") segment.rho = segment.atmosphere.compute_values(altitude / Units.km, type="rho") segment.mew = segment.atmosphere.compute_values(altitude / Units.km, type="mew") segment.v_inf = segment.M * segment.a #Method Test expected = 0.12 print 'Beech 99 at M = {0} and h = {1} meters'.format(segment.M, altitude) cn_b = taw_cnbeta(aircraft,segment) print 'Cn_beta = {0:.4f}'.format(cn_b) print 'Expected value = {}'.format(expected) print 'Percent Error = {0:.2f}%'.format(100.0*(cn_b-expected)/expected) print ' ' #Parameters Required #Using values for an SIAI Marchetti S-211 wing = SUAVE.Components.Wings.Wing() wing.area = 136.0 * Units.feet**2 wing.span = 26.3 * Units.feet wing.sweep_le = 19.5 * Units.deg wing.z_position = -1.1 * Units.feet wing.taper = 3.1/7.03 wing.aspect_ratio = wing.span**2/wing.area fuselage = SUAVE.Components.Fuselages.Fuselage() fuselage.side_area = 116.009 * Units.feet**2 fuselage.length = 30.9 * Units.feet fuselage.h_max = 5.1 * Units.feet fuselage.w_max = 5.9 * Units.feet fuselage.height_at_vroot_quarter_chord = 4.1 * Units.feet fuselage.height_at_quarter_length = 4.5 * Units.feet fuselage.height_at_three_quarters_length = 4.3 * Units.feet other_bodies = [] vertical = SUAVE.Components.Wings.Wing() vertical.span = 5.8 * Units.feet vertical.root_chord = 5.7 * Units.feet vertical.tip_chord = 2.0 * Units.feet vertical.sweep_le = 40.2 * Units.deg vertical.x_root_LE1 = 22.62 * Units.feet vertical.symmetric = False dz_centerline = 2.9 * Units.feet ref_vertical = extend_to_ref_area(vertical,dz_centerline) vertical.span = ref_vertical.ref_span vertical.area = ref_vertical.ref_area vertical.aspect_ratio = ref_vertical.ref_aspect_ratio vertical.x_root_LE = vertical.x_root_LE1 + ref_vertical.root_LE_change vertical.taper = vertical.tip_chord/ref_vertical.ref_root_chord vertical.effective_aspect_ratio = 2.65 vertical.x_ac_LE = trapezoid_ac_x(vertical) aircraft = SUAVE.Vehicle() aircraft.wing = wing aircraft.fuselage = fuselage aircraft.other_bodies = other_bodies aircraft.vertical = vertical aircraft.Mass_Props.pos_cg[0] = 16.6 * Units.feet segment = SUAVE.Analyses.Mission.Segments.Base_Segment() segment.M = 0.111 segment.atmosphere = SUAVE.Attributes.Atmospheres.Earth.US_Standard_1976() altitude = 0.0 * Units.feet segment.a = segment.atmosphere.compute_values(altitude / Units.km, type="a") segment.rho = segment.atmosphere.compute_values(altitude / Units.km, type="rho") segment.mew = segment.atmosphere.compute_values(altitude / Units.km, type="mew") segment.v_inf = segment.M * segment.a #Method Test print 'SIAI Marchetti S-211 at M = {0} and h = {1} meters'.format(segment.M, altitude) cn_b = taw_cnbeta(aircraft,segment) expected = 0.160 print 'Cn_beta = {0:.4f}'.format(cn_b) print 'Expected value = {}'.format(expected) print 'Percent Error = {0:.2f}%'.format(100.0*(cn_b-expected)/expected) print ' '""" for k, v in error.items(): assert (np.abs(v) < 0.1) return
def __call__(self, conditions): """ process vehicle to setup geometry, condititon and configuration Inputs: conditions - DataDict() of aerodynamic conditions results - DataDict() of Outputs: Assumptions: """ # unpack configuration = self.configuration geometry = self.geometry stability_model = self.stability_model q = conditions.freestream.dynamic_pressure Sref = geometry.reference_area mach = conditions.freestream.mach_number velocity = conditions.freestream.velocity density = conditions.freestream.density Span = geometry.wings['main_wing'].spans.projected mac = geometry.wings['main_wing'].chords.mean_aerodynamic aero = conditions.aerodynamics # set up data structures static_stability = Data() dynamic_stability = Data() # Calculate CL_alpha if not conditions.has_key('lift_curve_slope'): conditions.lift_curve_slope = datcom(geometry.wings['main_wing'], mach) # Calculate change in downwash with respect to change in angle of attack for surf in geometry.wings: sref = surf.areas.reference span = (surf.aspect_ratio * sref)**0.5 surf.CL_alpha = datcom(surf, mach) surf.ep_alpha = Supporting_Functions.ep_alpha( surf.CL_alpha, sref, span) # Static Stability Methods static_stability.cm_alpha = taw_cmalpha(geometry, mach, conditions, configuration) static_stability.cn_beta = taw_cnbeta(geometry, conditions, configuration) # Dynamic Stability if np.count_nonzero( configuration.mass_properties.moments_of_inertia.tensor) > 0: # Dynamic Stability Approximation Methods - valid for non-zero I tensor # Derivative of yawing moment with respect to the rate of yaw cDw = aero.drag_breakdown.parasite[ 'main_wing'].parasite_drag_coefficient # Might not be the correct value l_v = geometry.wings['vertical_stabilizer'].origin[ 0] + geometry.wings['vertical_stabilizer'].aerodynamic_center[ 0] - geometry.wings['main_wing'].origin[ 0] - geometry.wings['main_wing'].aerodynamic_center[0] dynamic_stability.cn_r = Supporting_Functions.cn_r( cDw, geometry.wings['vertical_stabilizer'].areas.reference, Sref, l_v, span, geometry.wings['vertical_stabilizer'].dynamic_pressure_ratio, geometry.wings['vertical_stabilizer'].CL_alpha) # Derivative of rolling moment with respect to roll rate dynamic_stability.cl_p = 0 # Need to see if there is a low fidelity way to calculate cl_p # Derivative of roll rate with respect to sideslip (dihedral effect) dynamic_stability.cl_beta = 0 # Need to see if there is a low fidelity way to calculate cl_beta # Derivative of pitching moment with respect to pitch rate l_t = geometry.wings['horizontal_stabilizer'].origin[ 0] + geometry.wings['horizontal_stabilizer'].aerodynamic_center[ 0] - geometry.wings['main_wing'].origin[ 0] - geometry.wings['main_wing'].aerodynamic_center[ 0] #Need to check this is the length of the horizontal tail moment arm dynamic_stability.cm_q = Supporting_Functions.cm_q( conditions.lift_curve_slope, l_t, mac) # Need to check Cm_i versus Cm_alpha # Derivative of pitching rate with respect to d(alpha)/d(t) dynamic_stability.cm_alpha_dot = Supporting_Functions.cm_alphadot( static_stability.cm_alpha, geometry.wings['horizontal_stabilizer'].ep_alpha, l_t, mac) # Need to check Cm_i versus Cm_alpha # Derivative of Z-axis force with respect to angle of attack dynamic_stability.cz_alpha = Supporting_Functions.cz_alpha( aero.drag_coefficient, conditions.lift_curve_slope) stability_model.dutch_roll = Approximations.dutch_roll( velocity, static_stability.cn_beta, Sref, density, Span, configuration.mass_properties.moments_of_inertia.tensor[2][2], dynamic_stability.cn_r) if dynamic_stability.cl_p != 0: stability_model.roll_tau = Approximations.roll( configuration.mass_properties.momen[2][2], Sref, density, velocity, Span, dynamic_stability.cl_p) dynamic_stability.cy_phi = Supporting_Functions.cy_phi( aero.lift_coefficient) dynamic_stability.cl_r = Supporting_Functions.cl_r( aero.lift_coefficient) # Will need to be changed stability_model.spiral_tau = Approximations.spiral( conditions.weights.total_mass, velocity, density, Sref, dynamic_stability.cl_p, static_stability.cn_beta, dynamic_stability.cy_phi, dynamic_stability.cl_beta, dynamic_stability.cn_r, dynamic_stability.cl_r) stability_model.short_period = Approximations.short_period( velocity, density, Sref, mac, dynamic_stability.cm_q, dynamic_stability.cz_alpha, conditions.weights.total_mass, static_stability.cm_alpha, configuration.mass_properties.moments_of_inertia.tensor[1][1], dynamic_stability.cm_alpha_dot) stability_model.phugoid = Approximations.phugoid( conditions.freestream.gravity, conditions.freestream.velocity, aero.drag_coefficient, aero.lift_coefficient) # Dynamic Stability Full Linearized Methods if aero.has_key( 'cy_beta' ) and dynamic_stability.cl_p != 0 and dynamic_stability.cl_beta != 0: theta = conditions.frames.wind.body_rotations[:, 1] dynamic_stability.cy_beta = aero.cy_beta dynamic_stability.cl_psi = Supporting_Functions.cy_psi( aero.lift_coefficient, theta) dynamic_stability.cL_u = 0 dynamic_stability.cz_u = Supporting_Functions.cz_u( aero.lift_coefficient, velocity, dynamic_stability.cL_u) dynamic_stability.cz_alpha_dot = Supporting_Functions.cz_alphadot( static_stability.cm_alpha, geometry.wings['horizontal_stabilizer'].ep_alpha) dynamic_stability.cz_q = Supporting_Functions.cz_q( static_stability.cm_alpha) dynamic_stability.cx_u = Supporting_Functions.cx_u( aero.drag_coefficient) dynamic_stability.cx_alpha = Supporting_Functions.cx_alpha( aero.lift_coefficient, conditions.lift_curve_slope) lateral_directional = Full_Linearized_Equations.lateral_directional( velocity, static_stability.cn_beta, Sref, density, Span, configuration.mass_properties.moments_of_inertia.tensor[2] [2], dynamic_stability.cn_r, configuration.mass_properties.Moments_Of_Inertia.tensor[0] [0], dynamic_stability.cl_p, configuration.mass_properties.moments_of_inertia.tensor[0] [2], dynamic_stability.cl_r, dynamic_stability.cl_beta, dynamic_stability.cn_p, dynamic_stability.cy_phi, dynamic_stability.cy_psi, dynamic_stability.cy_beta, conditions.weights.total_mass) longitudinal = Full_Linearized_Equations.longitudinal( velocity, density, Sref, mac, dynamic_stability.cm_q, dynamic_stability.cz_alpha, conditions.weights.total_mass, static_stability.cm_alpha, configuration.mass_properties.moments_of_inertia.tensor[1] [1], dynamic_stability.cm_alpha_dot, dynamic_stability.cz_u, dynamic_stability.cz_alpha_dot, dynamic_stability.cz_q, -aero.lift_coefficient, theta, dynamic_stability.cx_u, dynamic_stability.cx_alpha) stability_model.dutch_roll.natural_frequency = lateral_directional.dutch_natural_frequency stability_model.dutch_roll.damping_ratio = lateral_directional.dutch_damping_ratio stability_model.spiral_tau = lateral_directional.spiral_tau stability_model.roll_tau = lateral_directional.roll_tau stability_model.short_period.natural_frequency = longitudinal.short_natural_frequency stability_model.short_period.damping_ratio = longitudinal.short_damping_ratio stability_model.phugoid.natural_frequency = longitudinal.phugoid_natural_frequency stability_model.phugoid.damping_ratio = longitudinal.phugoid_damping_ratio # pack results results = Data() results.static = static_stability results.dynamic = dynamic_stability return results
def __call__(self,conditions): """ process vehicle to setup geometry, condititon and configuration Inputs: conditions - DataDict() of aerodynamic conditions results - DataDict() of Outputs: Assumptions: """ # unpack configuration = self.configuration geometry = self.geometry q = conditions.freestream.dynamic_pressure Sref = geometry.reference_area mach = conditions.freestream.mach_number velocity = conditions.freestream.velocity density = conditions.freestream.density Span = geometry.Wings['Main Wing'].span mac = geometry.Wings['Main Wing'].chord_mac aero = conditions.aerodynamics # Calculate CL_alpha if not conditions.has_key('lift_curve_slope'): conditions.lift_curve_slope = (datcom(geometry.Wings['Main Wing'],mach)) # Calculate change in downwash with respect to change in angle of attack for surf in geometry.Wings: e = surf.e sref = surf.sref span = (surf.ar * sref ) ** 0.5 surf.CL_alpha = datcom(surf,mach) surf.ep_alpha = Supporting_Functions.ep_alpha(surf.CL_alpha, sref, span, e) # Static Stability Methods aero.cm_alpha = taw_cmalpha(geometry,mach,conditions,configuration) aero.cn_beta = taw_cnbeta(geometry,conditions,configuration) if np.count_nonzero(configuration.mass_props.I_cg) > 0: # Dynamic Stability Approximation Methods if not aero.has_key('cn_r'): cDw = aero.drag_breakdown.parasite['Main Wing'].parasite_drag_coefficient # Might not be the correct value l_v = geometry.Wings['Vertical Stabilizer'].origin[0] + geometry.Wings['Vertical Stabilizer'].aero_center[0] - geometry.Wings['Main Wing'].origin[0] - geometry.Wings['Main Wing'].aero_center[0] aero.cn_r = Supporting_Functions.cn_r(cDw, geometry.Wings['Vertical Stabilizer'].sref, Sref, l_v, span, geometry.Wings['Vertical Stabilizer'].eta, geometry.Wings['Vertical Stabilizer'].CL_alpha) if not aero.has_key('cl_p'): aero.cl_p = 0 # Need to see if there is a low fidelity way to calculate cl_p if not aero.has_key('cl_beta'): aero.cl_beta = 0 # Need to see if there is a low fidelity way to calculate cl_beta l_t = geometry.Wings['Horizontal Stabilizer'].origin[0] + geometry.Wings['Horizontal Stabilizer'].aero_center[0] - geometry.Wings['Main Wing'].origin[0] - geometry.Wings['Main Wing'].aero_center[0] #Need to check this is the length of the horizontal tail moment arm if not aero.has_key('cm_q'): aero.cm_q = Supporting_Functions.cm_q(conditions.lift_curve_slope, l_t,mac) # Need to check Cm_i versus Cm_alpha if not aero.has_key('cm_alpha_dot'): aero.cm_alpha_dot = Supporting_Functions.cm_alphadot(aero.cm_alpha, geometry.Wings['Horizontal Stabilizer'].ep_alpha, l_t, mac) # Need to check Cm_i versus Cm_alpha if not aero.has_key('cz_alpha'): aero.cz_alpha = Supporting_Functions.cz_alpha(aero.drag_coefficient,conditions.lift_curve_slope) conditions.dutch_roll = Approximations.dutch_roll(velocity, aero.cn_beta, Sref, density, Span, configuration.mass_props.I_cg[2][2], aero.cn_r) if aero.cl_p != 0: roll_tau = Approximations.roll(configuration.mass_props.I_cg[2][2], Sref, density, velocity, Span, aero.cl_p) if aero.cl_beta != 0: aero.cy_phi = Supporting_Functions.cy_phi(aero.lift_coefficient) aero.cl_r = Supporting_Functions.cl_r( aero.lift_coefficient) # Will need to be changed spiral_tau = Approximations.spiral(conditions.weights.total_mass, velocity, density, Sref, aero.cl_p, aero.cn_beta, aero.cy_phi, aero.cl_beta, aero.cn_r, aero.cl_r) conditions.short_period = Approximations.short_period(velocity, density, Sref, mac, aero.cm_q, aero.cz_alpha, conditions.weights.total_mass, aero.cm_alpha, configuration.mass_props.I_cg[1][1], aero.cm_alpha_dot) conditions.phugoid = Approximations.phugoid(conditions.freestream.gravity, conditions.freestream.velocity, aero.drag_coefficient, aero.lift_coefficient) # Dynamic Stability Full Linearized Methods if aero.has_key('cy_beta') and aero.cl_p != 0 and aero.cl_beta != 0: if not aero.has_key('cy_psi'): theta = conditions.frames.wind.body_rotations[:,1] aero.cl_psi = Supporting_Functions.cy_psi(aero.lift_coefficient, theta) if not aero.has_key('cz_u'): if not aero.has_key('cL_u'): aero.cL_u = 0 aero.cz_u = Supporting_Functions.cz_u(aero.lift_coefficient,velocity,aero.cL_u) if not aero.has_key('cz_alpha_dot'): aero.cz_alpha_dot = Supporting_Functions.cz_alphadot(aero.cm_alpha, geometry.Wings['Horizontal Stabilizer'].ep_alpha) if not aero.has_key('cz_q'): aero.cz_q = Supporting_Functions.cz_q(aero.cm_alpha) if not aero.has_key('cx_u'): aero.cx_u = Supporting_Functions.cx_u(aero.drag_coefficient) if not aero.has_key('cx_alpha'): aero.cx_alpha = Supporting_Functions.cx_alpha(aero.lift_coefficient, conditions.lift_curve_slope) lateral_directional = Full_Linearized_Equations.lateral_directional(velocity, aero.cn_beta , Sref, density, Span, configuration.mass_props.I_cg[2][2], aero.cn_r, configuration.mass_props.I_cg[0][0], aero.cl_p, configuration.mass_props.I_cg[0][2], aero.cl_r, aero.cl_beta, aero.cn_p, aero.cy_phi, aero.cy_psi, aero.cy_beta, conditions.weights.total_mass) longitudinal = Full_Linearized_Equations.longitudinal(velocity, density, Sref, mac, aero.cm_q, aero.cz_alpha, conditions.weights.total_mass, aero.cm_alpha, configuration.mass_props.I_cg[1][1], aero.cm_alpha_dot, aero.cz_u, aero.cz_alpha_dot, aero.cz_q, -aero.lift_coefficient, theta, aero.cx_u, aero.cx_alpha) return
def __call__(self, conditions): """ Process vehicle to setup geometry, condititon and configuration Assumptions: None Source: N/A Inputs: conditions - DataDict() of aerodynamic conditions results - DataDict() of moment coeffients and stability and body axis derivatives Outputs: None Properties Used: self.geometry """ # unpack configuration = self.configuration geometry = self.geometry q = conditions.freestream.dynamic_pressure Sref = geometry.reference_area mach = conditions.freestream.mach_number velocity = conditions.freestream.velocity density = conditions.freestream.density Span = geometry.wings['main_wing'].spans.projected mac = geometry.wings['main_wing'].chords.mean_aerodynamic aero = conditions.aerodynamics # set up data structures stability = Data() stability.static = Data() stability.dynamic = Data() # Calculate CL_alpha conditions.lift_curve_slope = datcom(geometry.wings['main_wing'], mach) # Calculate change in downwash with respect to change in angle of attack for surf in geometry.wings: sref = surf.areas.reference span = (surf.aspect_ratio * sref)**0.5 surf.CL_alpha = datcom(surf, mach) surf.ep_alpha = Supporting_Functions.ep_alpha( surf.CL_alpha, sref, span) # Static Stability Methods stability.static.Cm_alpha, stability.static.Cm0, stability.static.CM = taw_cmalpha( geometry, mach, conditions, configuration) if 'vertical_stabilizer' in geometry.wings: stability.static.Cn_beta = taw_cnbeta(geometry, conditions, configuration) else: stability.static.Cn_beta = np.zeros_like(mach) # calculate the static margin stability.static.static_margin = -stability.static.Cm_alpha / conditions.lift_curve_slope # Dynamic Stability if np.count_nonzero( configuration.mass_properties.moments_of_inertia.tensor) > 0: # Dynamic Stability Approximation Methods - valid for non-zero I tensor # Derivative of yawing moment with respect to the rate of yaw cDw = aero.drag_breakdown.parasite[ 'main_wing'].parasite_drag_coefficient # Might not be the correct value l_v = geometry.wings['vertical_stabilizer'].origin[ 0] + geometry.wings['vertical_stabilizer'].aerodynamic_center[ 0] - geometry.wings['main_wing'].origin[ 0] - geometry.wings['main_wing'].aerodynamic_center[0] stability.static.Cn_r = Supporting_Functions.cn_r( cDw, geometry.wings['vertical_stabilizer'].areas.reference, Sref, l_v, span, geometry.wings['vertical_stabilizer'].dynamic_pressure_ratio, geometry.wings['vertical_stabilizer'].CL_alpha) # Derivative of rolling moment with respect to roll rate stability.static.Cl_p = Supporting_Functions.cl_p( conditions.lift_curve_slope, geometry) # Derivative of roll rate with respect to sideslip (dihedral effect) if 'dihedral' in geometry.wings['main_wing']: stability.static.Cl_beta = Supporting_Functions.cl_beta( geometry, stability.static.Cl_p) else: stability.static.Cl_beta = np.zeros(1) stability.static.Cy_beta = 0 # Derivative of pitching moment with respect to pitch rate l_t = geometry.wings['horizontal_stabilizer'].origin[ 0] + geometry.wings['horizontal_stabilizer'].aerodynamic_center[ 0] - geometry.wings['main_wing'].origin[ 0] - geometry.wings['main_wing'].aerodynamic_center[ 0] #Need to check this is the length of the horizontal tail moment arm stability.static.Cm_q = Supporting_Functions.cm_q( conditions.lift_curve_slope, l_t, mac) # Need to check Cm_i versus Cm_alpha # Derivative of pitching rate with respect to d(alpha)/d(t) stability.static.Cm_alpha_dot = Supporting_Functions.cm_alphadot( stability.static.Cm_alpha, geometry.wings['horizontal_stabilizer'].ep_alpha, l_t, mac) # Need to check Cm_i versus Cm_alpha # Derivative of Z-axis force with respect to angle of attack stability.static.Cz_alpha = Supporting_Functions.cz_alpha( aero.drag_coefficient, conditions.lift_curve_slope) dutch_roll = Approximations.dutch_roll( velocity, stability.static.Cn_beta, Sref, density, Span, configuration.mass_properties.moments_of_inertia.tensor[2][2], stability.static.Cn_r) stability.dynamic.dutchRollFreqHz = dutch_roll.natural_frequency stability.dynamic.dutchRollDamping = dutch_roll.damping_ratio if stability.static.Cl_p.all() != 0: stability.dynamic.rollSubsistenceTimeConstant = Approximations.roll( configuration.mass_properties.moments_of_inertia.tensor[2] [2], Sref, density, velocity, Span, stability.static.Cl_p) stability.static.Cy_phi = Supporting_Functions.cy_phi( aero.lift_coefficient) stability.static.Cl_r = Supporting_Functions.cl_r( aero.lift_coefficient) # Will need to be changed stability.dynamic.spiralSubsistenceTimeConstant = Approximations.spiral(conditions.weights.total_mass, velocity, density, Sref, stability.static.Cl_p, stability.static.Cn_beta, stability.static.Cy_phi,\ stability.static.Cl_beta, stability.static.Cn_r, stability.static.Cl_r) short_period_res = Approximations.short_period(velocity, density, Sref, mac, stability.static.Cm_q, stability.static.Cz_alpha, conditions.weights.total_mass, stability.static.Cm_alpha,\ configuration.mass_properties.moments_of_inertia.tensor[1][1], stability.static.Cm_alpha_dot) stability.dynamic.shortPeriodFreqHz = short_period_res.natural_frequency stability.dynamic.shortPeriodDamp = short_period_res.damping_ratio phugoid_res = Approximations.phugoid( conditions.freestream.gravity, conditions.freestream.velocity, aero.drag_coefficient, aero.lift_coefficient) stability.dynamic.phugoidFreqHz = phugoid_res.natural_frequency stability.dynamic.phugoidDamp = phugoid_res.damping_ratio # Dynamic Stability Full Linearized Methods if stability.static.Cy_beta != 0 and stability.static.Cl_p.all( ) != 0 and stability.static.Cl_beta.all() != 0: theta = conditions.frames.wind.body_rotations[:, 1] stability.static.Cy_psi = Supporting_Functions.cy_psi( aero.lift_coefficient, theta) stability.static.CL_u = 0 stability.static.Cz_u = Supporting_Functions.cz_u( aero.lift_coefficient, velocity, stability.static.cL_u) stability.static.Cz_alpha_dot = Supporting_Functions.cz_alphadot( stability.static.Cm_alpha, geometry.wings['horizontal_stabilizer'].ep_alpha) stability.static.Cz_q = Supporting_Functions.cz_q( stability.static.Cm_alpha) stability.static.Cx_u = Supporting_Functions.cx_u( aero.drag_coefficient) stability.static.Cx_alpha = Supporting_Functions.cx_alpha( aero.lift_coefficient, conditions.lift_curve_slope) lateral_directional = Full_Linearized_Equations.lateral_directional(velocity, stability.static.cn_beta , Sref, density, Span, configuration.mass_properties.moments_of_inertia.tensor[2][2], stability.static.Cn_r,\ configuration.mass_properties.moments_of_inertia.tensor[0][0], stability.static.Cl_p, configuration.mass_properties.moments_of_inertia.tensor[0][2], stability.static.Cl_r, stability.static.Cl_beta,\ stability.static.Cn_p, stability.static.Cy_phi, stability.static.Cy_psi, stability.static.Cy_beta, conditions.weights.total_mass) longitudinal = Full_Linearized_Equations.longitudinal(velocity, density, Sref, mac, stability.static.Cm_q, stability.static.Cz_alpha, conditions.weights.total_mass, stability.static.Cm_alpha, \ configuration.mass_properties.moments_of_inertia.tensor[1][1], stability.static.Cm_alpha_dot, stability.static.Cz_u, stability.static.Cz_alpha_dot, stability.static.Cz_q, -aero.lift_coefficient,\ theta, stability.static.Cx_u, stability.static.Cx_alpha) stability.dynamic.dutchRollFreqHz = lateral_directional.dutch_natural_frequency stability.dynamic.dutchRollDamping = lateral_directional.dutch_damping_ratio stability.dynamic.spiralSubsistenceTimeConstant = lateral_directional.spiral_tau stability.dynamic.rollSubsistenceTimeConstant = lateral_directional.roll_tau stability.dynamic.shortPeriodFreqHz = longitudinal.short_natural_frequency stability.dynamic.shortPeriodDamp = longitudinal.short_damping_ratio stability.dynamic.phugoidFreqHz = longitudinal.phugoid_natural_frequency stability.dynamic.phugoidDamp = longitudinal.phugoid_damping_ratio # pack results results = Data() results = stability return results
def __call__(self,conditions): """ process vehicle to setup geometry, condititon and configuration Inputs: conditions - DataDict() of aerodynamic conditions results - DataDict() of Outputs: Assumptions: """ # unpack configuration = self.configuration geometry = self.geometry stability_model = self.stability_model q = conditions.freestream.dynamic_pressure Sref = geometry.reference_area mach = conditions.freestream.mach_number velocity = conditions.freestream.velocity density = conditions.freestream.density Span = geometry.wings['main_wing'].spans.projected mac = geometry.wings['main_wing'].chords.mean_aerodynamic aero = conditions.aerodynamics # set up data structures static_stability = Data() dynamic_stability = Data() # Calculate CL_alpha if not conditions.has_key('lift_curve_slope'): conditions.lift_curve_slope = datcom(geometry.wings['main_wing'],mach) # Calculate change in downwash with respect to change in angle of attack for surf in geometry.wings: sref = surf.areas.reference span = (surf.aspect_ratio * sref ) ** 0.5 surf.CL_alpha = datcom(surf,mach) surf.ep_alpha = Supporting_Functions.ep_alpha(surf.CL_alpha, sref, span) # Static Stability Methods static_stability.cm_alpha = taw_cmalpha(geometry,mach,conditions,configuration) static_stability.cn_beta = taw_cnbeta(geometry,conditions,configuration) # Dynamic Stability if np.count_nonzero(configuration.mass_properties.moments_of_inertia.tensor) > 0: # Dynamic Stability Approximation Methods - valid for non-zero I tensor # Derivative of yawing moment with respect to the rate of yaw cDw = aero.drag_breakdown.parasite['main_wing'].parasite_drag_coefficient # Might not be the correct value l_v = geometry.wings['vertical_stabilizer'].origin[0] + geometry.wings['vertical_stabilizer'].aerodynamic_center[0] - geometry.wings['main_wing'].origin[0] - geometry.wings['main_wing'].aerodynamic_center[0] dynamic_stability.cn_r = Supporting_Functions.cn_r(cDw, geometry.wings['vertical_stabilizer'].areas.reference, Sref, l_v, span, geometry.wings['vertical_stabilizer'].dynamic_pressure_ratio, geometry.wings['vertical_stabilizer'].CL_alpha) # Derivative of rolling moment with respect to roll rate dynamic_stability.cl_p = 0 # Need to see if there is a low fidelity way to calculate cl_p # Derivative of roll rate with respect to sideslip (dihedral effect) dynamic_stability.cl_beta = 0 # Need to see if there is a low fidelity way to calculate cl_beta # Derivative of pitching moment with respect to pitch rate l_t = geometry.wings['horizontal_stabilizer'].origin[0] + geometry.wings['horizontal_stabilizer'].aerodynamic_center[0] - geometry.wings['main_wing'].origin[0] - geometry.wings['main_wing'].aerodynamic_center[0] #Need to check this is the length of the horizontal tail moment arm dynamic_stability.cm_q = Supporting_Functions.cm_q(conditions.lift_curve_slope, l_t,mac) # Need to check Cm_i versus Cm_alpha # Derivative of pitching rate with respect to d(alpha)/d(t) dynamic_stability.cm_alpha_dot = Supporting_Functions.cm_alphadot(static_stability.cm_alpha, geometry.wings['horizontal_stabilizer'].ep_alpha, l_t, mac) # Need to check Cm_i versus Cm_alpha # Derivative of Z-axis force with respect to angle of attack dynamic_stability.cz_alpha = Supporting_Functions.cz_alpha(aero.drag_coefficient,conditions.lift_curve_slope) stability_model.dutch_roll = Approximations.dutch_roll(velocity, static_stability.cn_beta, Sref, density, Span, configuration.mass_properties.moments_of_inertia.tensor[2][2], dynamic_stability.cn_r) if dynamic_stability.cl_p != 0: stability_model.roll_tau = Approximations.roll(configuration.mass_properties.momen[2][2], Sref, density, velocity, Span, dynamic_stability.cl_p) dynamic_stability.cy_phi = Supporting_Functions.cy_phi(aero.lift_coefficient) dynamic_stability.cl_r = Supporting_Functions.cl_r( aero.lift_coefficient) # Will need to be changed stability_model.spiral_tau = Approximations.spiral(conditions.weights.total_mass, velocity, density, Sref, dynamic_stability.cl_p, static_stability.cn_beta, dynamic_stability.cy_phi, dynamic_stability.cl_beta, dynamic_stability.cn_r, dynamic_stability.cl_r) stability_model.short_period = Approximations.short_period(velocity, density, Sref, mac, dynamic_stability.cm_q, dynamic_stability.cz_alpha, conditions.weights.total_mass, static_stability.cm_alpha, configuration.mass_properties.moments_of_inertia.tensor[1][1], dynamic_stability.cm_alpha_dot) stability_model.phugoid = Approximations.phugoid(conditions.freestream.gravity, conditions.freestream.velocity, aero.drag_coefficient, aero.lift_coefficient) # Dynamic Stability Full Linearized Methods if aero.has_key('cy_beta') and dynamic_stability.cl_p != 0 and dynamic_stability.cl_beta != 0: theta = conditions.frames.wind.body_rotations[:,1] dynamic_stability.cy_beta = aero.cy_beta dynamic_stability.cl_psi = Supporting_Functions.cy_psi(aero.lift_coefficient, theta) dynamic_stability.cL_u = 0 dynamic_stability.cz_u = Supporting_Functions.cz_u(aero.lift_coefficient,velocity,dynamic_stability.cL_u) dynamic_stability.cz_alpha_dot = Supporting_Functions.cz_alphadot(static_stability.cm_alpha, geometry.wings['horizontal_stabilizer'].ep_alpha) dynamic_stability.cz_q = Supporting_Functions.cz_q(static_stability.cm_alpha) dynamic_stability.cx_u = Supporting_Functions.cx_u(aero.drag_coefficient) dynamic_stability.cx_alpha = Supporting_Functions.cx_alpha(aero.lift_coefficient, conditions.lift_curve_slope) lateral_directional = Full_Linearized_Equations.lateral_directional(velocity, static_stability.cn_beta , Sref, density, Span, configuration.mass_properties.moments_of_inertia.tensor[2][2], dynamic_stability.cn_r, configuration.mass_properties.Moments_Of_Inertia.tensor[0][0], dynamic_stability.cl_p, configuration.mass_properties.moments_of_inertia.tensor[0][2], dynamic_stability.cl_r, dynamic_stability.cl_beta, dynamic_stability.cn_p, dynamic_stability.cy_phi, dynamic_stability.cy_psi, dynamic_stability.cy_beta, conditions.weights.total_mass) longitudinal = Full_Linearized_Equations.longitudinal(velocity, density, Sref, mac, dynamic_stability.cm_q, dynamic_stability.cz_alpha, conditions.weights.total_mass, static_stability.cm_alpha, configuration.mass_properties.moments_of_inertia.tensor[1][1], dynamic_stability.cm_alpha_dot, dynamic_stability.cz_u, dynamic_stability.cz_alpha_dot, dynamic_stability.cz_q, -aero.lift_coefficient, theta, dynamic_stability.cx_u, dynamic_stability.cx_alpha) stability_model.dutch_roll.natural_frequency = lateral_directional.dutch_natural_frequency stability_model.dutch_roll.damping_ratio = lateral_directional.dutch_damping_ratio stability_model.spiral_tau = lateral_directional.spiral_tau stability_model.roll_tau = lateral_directional.roll_tau stability_model.short_period.natural_frequency = longitudinal.short_natural_frequency stability_model.short_period.damping_ratio = longitudinal.short_damping_ratio stability_model.phugoid.natural_frequency = longitudinal.phugoid_natural_frequency stability_model.phugoid.damping_ratio = longitudinal.phugoid_damping_ratio # pack results results = Data() results.static = static_stability results.dynamic = dynamic_stability return results
segment = SUAVE.Attributes.Missions.Segments.Base_Segment() segment.M = 0.198 segment.atmosphere = SUAVE.Attributes.Atmospheres.Earth.US_Standard_1976() altitude = 0.0 * Units.feet segment.a = segment.atmosphere.compute_values(altitude / Units.km, type="a") segment.rho = segment.atmosphere.compute_values(altitude / Units.km, type="rho") segment.mew = segment.atmosphere.compute_values(altitude / Units.km, type="mew") segment.v_inf = segment.M * segment.a #Method Test print '<<Test run of the taw_cnbeta() method>>' print 'Boeing 747 at M = {0} and h = {1} meters'.format(segment.M, altitude) cn_b = taw_cnbeta(aircraft,segment) expected = 0.184 print 'Cn_beta = {0:.4f}'.format(cn_b) print 'Expected value = {}'.format(expected) print 'Percent Error = {0:.2f}%'.format(100.0*(cn_b-expected)/expected) print ' ' #Parameters Required #Using values for a Beechcraft Model 99 #MODEL DOES NOT ACCOUNT FOR DESTABILIZING EFFECTS OF PROPELLERS! wing = SUAVE.Components.Wings.Wing() wing.area = 280.0 * Units.feet**2 wing.span = 46.0 * Units.feet wing.sweep_le = 3.0 * Units.deg
def __call__(self, conditions): """ process vehicle to setup geometry, condititon and configuration Inputs: conditions - DataDict() of aerodynamic conditions results - DataDict() of Outputs: Assumptions: """ # unpack configuration = self.configuration geometry = self.geometry stability_model = self.stability_model q = conditions.freestream.dynamic_pressure Sref = geometry.reference_area mach = conditions.freestream.mach_number velocity = conditions.freestream.velocity density = conditions.freestream.density Span = geometry.wings['Main Wing'].spans.projected mac = geometry.wings['Main Wing'].chords.mean_aerodynamic aero = conditions.aerodynamics # Calculate CL_alpha if not conditions.has_key('lift_curve_slope'): conditions.lift_curve_slope = datcom(geometry.wings['Main Wing'], mach) # Calculate change in downwash with respect to change in angle of attack for surf in geometry.wings: e = surf.span_efficiency sref = surf.areas.reference span = (surf.aspect_ratio * sref)**0.5 surf.CL_alpha = datcom(surf, mach) surf.ep_alpha = Supporting_Functions.ep_alpha( surf.CL_alpha, sref, span, e) # Static Stability Methods aero.cm_alpha = taw_cmalpha(geometry, mach, conditions, configuration) aero.cn_beta = taw_cnbeta(geometry, conditions, configuration) if np.count_nonzero( configuration.mass_properties.moments_of_inertia.tensor) > 0: # Dynamic Stability Approximation Methods if not aero.has_key('cn_r'): cDw = aero.drag_breakdown.parasite[ 'Main Wing'].parasite_drag_coefficient # Might not be the correct value l_v = geometry.wings['Vertical Stabilizer'].origin[ 0] + geometry.wings[ 'Vertical Stabilizer'].aerodynamic_center[ 0] - geometry.wings['Main Wing'].origin[ 0] - geometry.wings[ 'Main Wing'].aerodynamic_center[0] aero.cn_r = Supporting_Functions.cn_r( cDw, geometry.wings['Vertical Stabilizer'].areas.reference, Sref, l_v, span, geometry.wings['Vertical Stabilizer'].eta, geometry.wings['Vertical Stabilizer'].CL_alpha) if not aero.has_key('cl_p'): aero.cl_p = 0 # Need to see if there is a low fidelity way to calculate cl_p if not aero.has_key('cl_beta'): aero.cl_beta = 0 # Need to see if there is a low fidelity way to calculate cl_beta l_t = geometry.wings['Horizontal Stabilizer'].origin[ 0] + geometry.wings['Horizontal Stabilizer'].aerodynamic_center[ 0] - geometry.wings['Main Wing'].origin[ 0] - geometry.wings['Main Wing'].aerodynamic_center[ 0] #Need to check this is the length of the horizontal tail moment arm if not aero.has_key('cm_q'): aero.cm_q = Supporting_Functions.cm_q( conditions.lift_curve_slope, l_t, mac) # Need to check Cm_i versus Cm_alpha if not aero.has_key('cm_alpha_dot'): aero.cm_alpha_dot = Supporting_Functions.cm_alphadot( aero.cm_alpha, geometry.wings['Horizontal Stabilizer'].ep_alpha, l_t, mac) # Need to check Cm_i versus Cm_alpha if not aero.has_key('cz_alpha'): aero.cz_alpha = Supporting_Functions.cz_alpha( aero.drag_coefficient, conditions.lift_curve_slope) stability_model.dutch_roll = Approximations.dutch_roll( velocity, aero.cn_beta, Sref, density, Span, configuration.mass_properties.moments_of_inertia.tensor[2][2], aero.cn_r) if aero.cl_p != 0: stability_model.roll_tau = Approximations.roll( configuration.mass_properties.momen[2][2], Sref, density, velocity, Span, aero.cl_p) if aero.cl_beta != 0: aero.cy_phi = Supporting_Functions.cy_phi( aero.lift_coefficient) aero.cl_r = Supporting_Functions.cl_r( aero.lift_coefficient) # Will need to be changed stability_model.spiral_tau = Approximations.spiral( conditions.weights.total_mass, velocity, density, Sref, aero.cl_p, aero.cn_beta, aero.cy_phi, aero.cl_beta, aero.cn_r, aero.cl_r) stability_model.short_period = Approximations.short_period( velocity, density, Sref, mac, aero.cm_q, aero.cz_alpha, conditions.weights.total_mass, aero.cm_alpha, configuration.mass_properties.moments_of_inertia.tensor[1][1], aero.cm_alpha_dot) stability_model.phugoid = Approximations.phugoid( conditions.freestream.gravity, conditions.freestream.velocity, aero.drag_coefficient, aero.lift_coefficient) # Dynamic Stability Full Linearized Methods if aero.has_key( 'cy_beta') and aero.cl_p != 0 and aero.cl_beta != 0: if not aero.has_key('cy_psi'): theta = conditions.frames.wind.body_rotations[:, 1] aero.cl_psi = Supporting_Functions.cy_psi( aero.lift_coefficient, theta) if not aero.has_key('cz_u'): if not aero.has_key('cL_u'): aero.cL_u = 0 aero.cz_u = Supporting_Functions.cz_u( aero.lift_coefficient, velocity, aero.cL_u) if not aero.has_key('cz_alpha_dot'): aero.cz_alpha_dot = Supporting_Functions.cz_alphadot( aero.cm_alpha, geometry.wings['Horizontal Stabilizer'].ep_alpha) if not aero.has_key('cz_q'): aero.cz_q = Supporting_Functions.cz_q(aero.cm_alpha) if not aero.has_key('cx_u'): aero.cx_u = Supporting_Functions.cx_u( aero.drag_coefficient) if not aero.has_key('cx_alpha'): aero.cx_alpha = Supporting_Functions.cx_alpha( aero.lift_coefficient, conditions.lift_curve_slope) lateral_directional = Full_Linearized_Equations.lateral_directional( velocity, aero.cn_beta, Sref, density, Span, configuration.mass_properties.moments_of_inertia.tensor[2] [2], aero.cn_r, configuration.mass_properties.Moments_Of_Inertia.tensor[0] [0], aero.cl_p, configuration.mass_properties.moments_of_inertia.tensor[0] [2], aero.cl_r, aero.cl_beta, aero.cn_p, aero.cy_phi, aero.cy_psi, aero.cy_beta, conditions.weights.total_mass) longitudinal = Full_Linearized_Equations.longitudinal( velocity, density, Sref, mac, aero.cm_q, aero.cz_alpha, conditions.weights.total_mass, aero.cm_alpha, configuration.mass_properties.moments_of_inertia.tensor[1] [1], aero.cm_alpha_dot, aero.cz_u, aero.cz_alpha_dot, aero.cz_q, -aero.lift_coefficient, theta, aero.cx_u, aero.cx_alpha) stability_model.dutch_roll.natural_frequency = lateral_directional.dutch_natural_frequency stability_model.dutch_roll.damping_ratio = lateral_directional.dutch_damping_ratio stability_model.spiral_tau = lateral_directional.spiral_tau stability_model.roll_tau = lateral_directional.roll_tau stability_model.short_period.natural_frequency = longitudinal.short_natural_frequency stability_model.short_period.damping_ratio = longitudinal.short_damping_ratio stability_model.phugoid.natural_frequency = longitudinal.phugoid_natural_frequency stability_model.phugoid.damping_ratio = longitudinal.phugoid_damping_ratio return