Exemplo n.º 1
0
    def setup_aero(self):
        """
        Specific method to add the necessary components to the problem for an
        aerodynamic problem.
        """

        # Set the problem name if the user doesn't
        if 'prob_name' not in self.prob_dict.keys():
            self.prob_dict['prob_name'] = 'aero'

        # Create the base root-level group
        root = Group()

        # Create the problem and assign the root group
        self.prob = Problem()
        self.prob.root = root

        # Loop over each surface in the surfaces list
        for surface in self.surfaces:

            # Get the surface name and create a group to contain components
            # only for this surface
            name = surface['name']
            tmp_group = Group()

            # Add independent variables that do not belong to a specific component
            indep_vars = [('twist_cp', numpy.zeros(surface['num_twist'])),
                          ('dihedral', surface['dihedral']),
                          ('sweep', surface['sweep']),
                          ('span', surface['span']),
                          ('taper', surface['taper']),
                          ('disp', numpy.zeros((surface['num_y'], 6)))]

            # Obtain the Jacobian to interpolate the data from the b-spline
            # control points
            jac_twist = get_bspline_mtx(surface['num_twist'], surface['num_y'])

            # Add aero components to the surface-specific group
            tmp_group.add('indep_vars',
                          IndepVarComp(indep_vars),
                          promotes=['*'])
            tmp_group.add('twist_bsp',
                          Bspline('twist_cp', 'twist', jac_twist),
                          promotes=['*'])
            tmp_group.add('mesh', GeometryMesh(surface), promotes=['*'])
            tmp_group.add('def_mesh',
                          TransferDisplacements(surface),
                          promotes=['*'])
            tmp_group.add('vlmgeom', VLMGeometry(surface), promotes=['*'])

            # Add tmp_group to the problem as the name of the surface.
            # Note that is a group and performance group for each
            # individual surface.
            name_orig = name.strip('_')
            name = name_orig
            exec(name + ' = tmp_group')
            exec('root.add("' + name + '", ' + name + ', promotes=[])')

            # Add a performance group for each surface
            name = name_orig + '_perf'
            exec('root.add("' + name + '", ' + 'VLMFunctionals(surface)' +
                 ', promotes=["v", "alpha", "M", "Re", "rho"])')

        # Add problem information as an independent variables component
        prob_vars = [('v', self.prob_dict['v']),
                     ('alpha', self.prob_dict['alpha']),
                     ('M', self.prob_dict['M']), ('Re', self.prob_dict['Re']),
                     ('rho', self.prob_dict['rho'])]
        root.add('prob_vars', IndepVarComp(prob_vars), promotes=['*'])

        # Add a single 'aero_states' component that solves for the circulations
        # and forces from all the surfaces.
        # While other components only depends on a single surface,
        # this component requires information from all surfaces because
        # each surface interacts with the others.
        root.add('aero_states',
                 VLMStates(self.surfaces, self.prob_dict),
                 promotes=['circulations', 'v', 'alpha', 'rho'])

        # Explicitly connect parameters from each surface's group and the common
        # 'aero_states' group.
        # This is necessary because the VLMStates component requires information
        # from each surface, but this information is stored within each
        # surface's group.
        for surface in self.surfaces:
            name = surface['name']

            # Perform the connections with the modified names within the
            # 'aero_states' group.
            root.connect(name[:-1] + '.def_mesh',
                         'aero_states.' + name + 'def_mesh')
            root.connect(name[:-1] + '.b_pts', 'aero_states.' + name + 'b_pts')
            root.connect(name[:-1] + '.c_pts', 'aero_states.' + name + 'c_pts')
            root.connect(name[:-1] + '.normals',
                         'aero_states.' + name + 'normals')

            # Connect the results from 'aero_states' to the performance groups
            root.connect('aero_states.' + name + 'sec_forces',
                         name + 'perf' + '.sec_forces')

            # Connect S_ref for performance calcs
            root.connect(name[:-1] + '.S_ref', name + 'perf' + '.S_ref')

        # Actually set up the problem
        self.setup_prob()
Exemplo n.º 2
0
    def setup_aerostruct(self):
        """
        Specific method to add the necessary components to the problem for an
        aerostructural problem.
        """

        # Set the problem name if the user doesn't
        if 'prob_name' not in self.prob_dict.keys():
            self.prob_dict['prob_name'] = 'aerostruct'

        # Create the base root-level group
        root = Group()
        coupled = Group()

        # Create the problem and assign the root group
        self.prob = Problem()
        self.prob.root = root

        # Loop over each surface in the surfaces list
        for surface in self.surfaces:

            # Get the surface name and create a group to contain components
            # only for this surface
            name = surface['name']
            tmp_group = Group()

            # Add independent variables that do not belong to a specific component
            indep_vars = [
                ('twist_cp', numpy.zeros(surface['num_twist'])),
                ('thickness_cp', numpy.ones(surface['num_thickness']) *
                 numpy.max(surface['t'])), ('r', surface['r']),
                ('dihedral', surface['dihedral']), ('sweep', surface['sweep']),
                ('span', surface['span']), ('taper', surface['taper'])
            ]

            # Obtain the Jacobians to interpolate the data from the b-spline
            # control points
            jac_twist = get_bspline_mtx(surface['num_twist'], surface['num_y'])
            jac_thickness = get_bspline_mtx(surface['num_thickness'],
                                            surface['num_y'] - 1)

            # Add components to include in the surface's group
            tmp_group.add('indep_vars',
                          IndepVarComp(indep_vars),
                          promotes=['*'])
            tmp_group.add('twist_bsp',
                          Bspline('twist_cp', 'twist', jac_twist),
                          promotes=['*'])
            tmp_group.add('thickness_bsp',
                          Bspline('thickness_cp', 'thickness', jac_thickness),
                          promotes=['*'])
            tmp_group.add('tube', MaterialsTube(surface), promotes=['*'])

            # Add tmp_group to the problem with the name of the surface.
            name_orig = name
            name = name[:-1]
            exec(name + ' = tmp_group')
            exec('root.add("' + name + '", ' + name + ', promotes=[])')

            # Add components to the 'coupled' group for each surface.
            # The 'coupled' group must contain all components and parameters
            # needed to converge the aerostructural system.
            tmp_group = Group()
            tmp_group.add('mesh', GeometryMesh(surface), promotes=['*'])
            tmp_group.add('def_mesh',
                          TransferDisplacements(surface),
                          promotes=['*'])
            tmp_group.add('aero_geom', VLMGeometry(surface), promotes=['*'])
            tmp_group.add('struct_states',
                          SpatialBeamStates(surface),
                          promotes=['*'])
            tmp_group.struct_states.ln_solver = LinearGaussSeidel()

            name = name_orig
            exec(name + ' = tmp_group')
            exec('coupled.add("' + name[:-1] + '", ' + name + ', promotes=[])')

            # Add a loads component to the coupled group
            exec('coupled.add("' + name_orig + 'loads' + '", ' +
                 'TransferLoads(surface)' + ', promotes=[])')

            # Add a performance group which evaluates the data after solving
            # the coupled system
            tmp_group = Group()

            tmp_group.add('struct_funcs',
                          SpatialBeamFunctionals(surface),
                          promotes=['*'])
            tmp_group.add('aero_funcs',
                          VLMFunctionals(surface),
                          promotes=['*'])

            name = name_orig + 'perf'
            exec(name + ' = tmp_group')
            exec('root.add("' + name + '", ' + name +
                 ', promotes=["rho", "v", "alpha", "Re", "M"])')

        # Add a single 'aero_states' component for the whole system within the
        # coupled group.
        coupled.add('aero_states',
                    VLMStates(self.surfaces, self.prob_dict),
                    promotes=['v', 'alpha', 'rho'])

        # Explicitly connect parameters from each surface's group and the common
        # 'aero_states' group.
        for surface in self.surfaces:
            name = surface['name']

            # Perform the connections with the modified names within the
            # 'aero_states' group.
            root.connect('coupled.' + name[:-1] + '.def_mesh',
                         'coupled.aero_states.' + name + 'def_mesh')
            root.connect('coupled.' + name[:-1] + '.b_pts',
                         'coupled.aero_states.' + name + 'b_pts')
            root.connect('coupled.' + name[:-1] + '.c_pts',
                         'coupled.aero_states.' + name + 'c_pts')
            root.connect('coupled.' + name[:-1] + '.normals',
                         'coupled.aero_states.' + name + 'normals')

            # Connect the results from 'aero_states' to the performance groups
            root.connect('coupled.aero_states.' + name + 'sec_forces',
                         name + 'perf' + '.sec_forces')

            # Connect the results from 'coupled' to the performance groups
            root.connect('coupled.' + name[:-1] + '.def_mesh',
                         'coupled.' + name + 'loads.def_mesh')
            root.connect('coupled.aero_states.' + name + 'sec_forces',
                         'coupled.' + name + 'loads.sec_forces')
            root.connect('coupled.' + name + 'loads.loads',
                         name + 'perf.loads')

            # Connect the output of the loads component with the FEM
            # displacement parameter. This links the coupling within the coupled
            # group that necessitates the subgroup solver.
            root.connect('coupled.' + name + 'loads.loads',
                         'coupled.' + name[:-1] + '.loads')

            # Connect aerodyamic design variables
            root.connect(name[:-1] + '.dihedral',
                         'coupled.' + name[:-1] + '.dihedral')
            root.connect(name[:-1] + '.span', 'coupled.' + name[:-1] + '.span')
            root.connect(name[:-1] + '.sweep',
                         'coupled.' + name[:-1] + '.sweep')
            root.connect(name[:-1] + '.taper',
                         'coupled.' + name[:-1] + '.taper')
            root.connect(name[:-1] + '.twist',
                         'coupled.' + name[:-1] + '.twist')

            # Connect structural design variables
            root.connect(name[:-1] + '.A', 'coupled.' + name[:-1] + '.A')
            root.connect(name[:-1] + '.Iy', 'coupled.' + name[:-1] + '.Iy')
            root.connect(name[:-1] + '.Iz', 'coupled.' + name[:-1] + '.Iz')
            root.connect(name[:-1] + '.J', 'coupled.' + name[:-1] + '.J')

            # Connect performance calculation variables
            root.connect(name[:-1] + '.r', name + 'perf.r')
            root.connect(name[:-1] + '.A', name + 'perf.A')

            # Connection performance functional variables
            root.connect(name + 'perf.weight', 'fuelburn.' + name + 'weight')
            root.connect(name + 'perf.weight', 'eq_con.' + name + 'weight')
            root.connect(name + 'perf.L', 'eq_con.' + name + 'L')
            root.connect(name + 'perf.CL', 'fuelburn.' + name + 'CL')
            root.connect(name + 'perf.CD', 'fuelburn.' + name + 'CD')

            # Connect paramters from the 'coupled' group to the performance
            # group.
            root.connect('coupled.' + name[:-1] + '.nodes',
                         name + 'perf.nodes')
            root.connect('coupled.' + name[:-1] + '.disp', name + 'perf.disp')
            root.connect('coupled.' + name[:-1] + '.S_ref',
                         name + 'perf.S_ref')

        # Set solver properties for the coupled group
        coupled.ln_solver = ScipyGMRES()
        coupled.ln_solver.options['iprint'] = 1
        coupled.ln_solver.preconditioner = LinearGaussSeidel()
        coupled.aero_states.ln_solver = LinearGaussSeidel()

        coupled.nl_solver = NLGaussSeidel()
        coupled.nl_solver.options['iprint'] = 1

        # Ensure that the groups are ordered correctly within the coupled group
        # so that a system with multiple surfaces is solved corretly.
        order_list = []
        for surface in self.surfaces:
            order_list.append(surface['name'][:-1])
        order_list.append('aero_states')
        for surface in self.surfaces:
            order_list.append(surface['name'] + 'loads')
        coupled.set_order(order_list)

        # Add the coupled group to the root problem
        root.add('coupled', coupled, promotes=['v', 'alpha', 'rho'])

        # Add problem information as an independent variables component
        prob_vars = [('v', self.prob_dict['v']),
                     ('alpha', self.prob_dict['alpha']),
                     ('M', self.prob_dict['M']), ('Re', self.prob_dict['Re']),
                     ('rho', self.prob_dict['rho'])]
        root.add('prob_vars', IndepVarComp(prob_vars), promotes=['*'])

        # Add functionals to evaluate performance of the system.
        # Note that only the interesting results are promoted here; not all
        # of the parameters.
        root.add('fuelburn',
                 FunctionalBreguetRange(self.surfaces, self.prob_dict),
                 promotes=['fuelburn'])
        root.add('eq_con',
                 FunctionalEquilibrium(self.surfaces, self.prob_dict),
                 promotes=['eq_con', 'fuelburn'])

        # Actually set up the system
        self.setup_prob()
Exemplo n.º 3
0
    def setup_struct(self):
        """
        Specific method to add the necessary components to the problem for a
        structural problem.
        """

        # Set the problem name if the user doesn't
        if 'prob_name' not in self.prob_dict.keys():
            self.prob_dict['prob_name'] = 'struct'

        # Create the base root-level group
        root = Group()

        # Create the problem and assign the root group
        self.prob = Problem()
        self.prob.root = root

        # Loop over each surface in the surfaces list
        for surface in self.surfaces:

            # Get the surface name and create a group to contain components
            # only for this surface.
            # This group's name is whatever the surface's name is.
            # The default is 'wing'.
            name = surface['name']
            tmp_group = Group()

            surface['r'] = surface['r'] / 5
            surface['t'] = surface['r'] / 20

            # Add independent variables that do not belong to a specific component.
            # Note that these are the only ones necessary for structual-only
            # analysis and optimization.
            indep_vars = [
                ('thickness_cp', numpy.ones(surface['num_thickness']) *
                 numpy.max(surface['t'])), ('r', surface['r']),
                ('loads', surface['loads'])
            ]

            # Obtain the Jacobians to interpolate the data from the b-spline
            # control points
            jac_twist = get_bspline_mtx(surface['num_twist'], surface['num_y'])
            jac_thickness = get_bspline_mtx(surface['num_thickness'],
                                            surface['num_y'] - 1)

            # Add structural components to the surface-specific group
            tmp_group.add('indep_vars',
                          IndepVarComp(indep_vars),
                          promotes=['*'])
            tmp_group.add('twist_bsp',
                          Bspline('twist_cp', 'twist', jac_twist),
                          promotes=['*'])
            tmp_group.add('thickness_bsp',
                          Bspline('thickness_cp', 'thickness', jac_thickness),
                          promotes=['*'])
            tmp_group.add('mesh', GeometryMesh(surface), promotes=['*'])
            tmp_group.add('tube', MaterialsTube(surface), promotes=['*'])
            tmp_group.add('struct_states',
                          SpatialBeamStates(surface),
                          promotes=['*'])
            tmp_group.add('struct_funcs',
                          SpatialBeamFunctionals(surface),
                          promotes=['*'])

            # Add tmp_group to the problem with the name of the surface.
            # The default is 'wing'.
            nm = name
            name = name[:-1]
            exec(name + ' = tmp_group')
            exec('root.add("' + name + '", ' + name + ', promotes=[])')

        # Actually set up the problem
        self.setup_prob()
Exemplo n.º 4
0
def struct(loads, params):

    # Unpack variables
    mesh = params.get('mesh')
    num_x = params.get('num_x')
    num_y = params.get('num_y')
    span = params.get('span')
    twist_cp = params.get('twist_cp')
    thickness_cp = params.get('thickness_cp')
    v = params.get('v')
    alpha = params.get('alpha')
    rho = params.get('rho')
    r = params.get('r')
    t = params.get('t')
    aero_ind = params.get('aero_ind')
    fem_ind = params.get('fem_ind')
    num_thickness = params.get('num_thickness')
    num_twist = params.get('num_twist')
    sweep = params.get('sweep')
    taper = params.get('taper')
    disp = params.get('disp')
    dihedral = params.get('dihedral')
    E = params.get('E')
    G = params.get('G')
    stress = params.get('stress')
    mrho = params.get('mrho')
    tot_n_fem = params.get('tot_n_fem')
    num_surf = params.get('num_surf')
    jac_twist = params.get('jac_twist')
    jac_thickness = params.get('jac_thickness')
    check = params.get('check')
    out_stream = params.get('out_stream')

    # Define the design variables
    des_vars = [
        ('twist_cp', twist_cp),
        ('thickness_cp', thickness_cp),
        ('r', r),
        # ('dihedral', dihedral),
        # ('sweep', sweep),
        # ('span', span),
        # ('taper', taper),
        # ('v', v),
        # ('alpha', alpha),
        # ('rho', rho),
        # ('disp', disp),
        ('loads', loads)
    ]

    root = Group()

    root.add(
        'des_vars',
        IndepVarComp(des_vars),
        #  promotes=['thickness_cp','r','loads'])
        promotes=['*'])
    # root.add('twist_bsp',  # What is this doing?
    #          Bspline('twist_cp', 'twist', jac_twist),
    #          promotes=['*'])
    root.add('twist_bsp',
             Bspline('twist_cp', 'twist', jac_twist),
             promotes=['*'])
    root.add(
        'thickness_bsp',  # What is this doing?
        Bspline('thickness_cp', 'thickness', jac_thickness),
        #  promotes=['thickness'])
        promotes=['*'])
    root.add('mesh', GeometryMesh(mesh, aero_ind), promotes=['*'])
    root.add(
        'tube',
        MaterialsTube(fem_ind),
        #  promotes=['r','thickness','A','Iy','Iz','J'])
        promotes=['*'])
    root.add(
        'spatialbeamstates',
        SpatialBeamStates(aero_ind, fem_ind, E, G),
        #  promotes=[
        #     'mesh', # ComputeNodes
        #     'A','Iy','Iz','J','loads', # SpatialBeamFEM
        #     'disp' # SpatialBeamDisp
        #  ])
        promotes=['*'])
    root.add(
        'transferdisp',
        TransferDisplacements(aero_ind, fem_ind),
        #  promotes=['mesh','disp','def_mesh'])
        promotes=['*'])

    prob = Problem()
    prob.root = root
    prob.setup(check=check, out_stream=out_stream)
    prob.run()

    return prob['def_mesh']  # Output the def_mesh matrix
Exemplo n.º 5
0
    ('v', v),
    ('alpha', alpha),
    ('rho', rho),
    ('r', r),
    ('t', t),
    ('aero_ind', aero_ind)
]

############################################################
# These are your components, put them in the correct groups.
# indep_vars_comp, tube_comp, and weiss_func_comp have been
# done for you as examples
############################################################

indep_vars_comp = IndepVarComp(indep_vars)
twist_comp = Bspline('twist_cp', 'twist', jac_twist)
thickness_comp = Bspline('thickness_cp', 'thickness', jac_thickness)
tube_comp = MaterialsTube(fem_ind)

mesh_comp = GeometryMesh(mesh, aero_ind)
spatialbeamstates_comp = SpatialBeamStates(aero_ind, fem_ind, E, G)
def_mesh_comp = TransferDisplacements(aero_ind, fem_ind)
vlmstates_comp = VLMStates(aero_ind)
loads_comp = TransferLoads(aero_ind, fem_ind)

vlmfuncs_comp = VLMFunctionals(aero_ind, CL0, CD0)
spatialbeamfuncs_comp = SpatialBeamFunctionals(aero_ind, fem_ind, E, G, stress, mrho)
fuelburn_comp = FunctionalBreguetRange(W0, CT, a, R, M, aero_ind)
eq_con_comp = FunctionalEquilibrium(W0, aero_ind)

############################################################
Exemplo n.º 6
0
    def setup_aerostruct(self):
        """
        Specific method to add the necessary components to the problem for an
        aerostructural problem.
        """

        # Set the problem name if the user doesn't
        if 'prob_name' not in self.prob_dict.keys():
            self.prob_dict['prob_name'] = 'aerostruct'

        # Create the base root-level group
        root = Group()
        coupled = Group()

        # Create the problem and assign the root group
        self.prob = Problem()
        self.prob.root = root

        # Loop over each surface in the surfaces list
        for surface in self.surfaces:

            # Get the surface name and create a group to contain components
            # only for this surface
            name = surface['name']
            tmp_group = Group()

            # Add independent variables that do not belong to a specific component
            indep_vars = [
                (name + 'twist_cp', numpy.zeros(surface['num_twist'])),
                (name + 'thickness_cp', numpy.ones(surface['num_thickness']) *
                 numpy.max(surface['t'])), (name + 'r', surface['r']),
                (name + 'dihedral', surface['dihedral']),
                (name + 'sweep', surface['sweep']),
                (name + 'span', surface['span']),
                (name + 'taper', surface['taper'])
            ]

            # Obtain the Jacobians to interpolate the data from the b-spline
            # control points
            jac_twist = get_bspline_mtx(surface['num_twist'], surface['num_y'])
            jac_thickness = get_bspline_mtx(surface['num_thickness'],
                                            surface['num_y'] - 1)

            # Add components to include in the '_pre_solve' group
            tmp_group.add('indep_vars',
                          IndepVarComp(indep_vars),
                          promotes=['*'])
            tmp_group.add('twist_bsp',
                          Bspline(name + 'twist_cp', name + 'twist',
                                  jac_twist),
                          promotes=['*'])
            tmp_group.add('thickness_bsp',
                          Bspline(name + 'thickness_cp', name + 'thickness',
                                  jac_thickness),
                          promotes=['*'])
            tmp_group.add('tube', MaterialsTube(surface), promotes=['*'])

            # Add tmp_group to the problem with the name of the surface and
            # '_pre_solve' appended.
            name_orig = name  #.strip('_')
            name = name + 'pre_solve'
            exec(name + ' = tmp_group')
            exec('root.add("' + name + '", ' + name + ', promotes=["*"])')

            # Add components to the 'coupled' group for each surface
            tmp_group = Group()
            tmp_group.add('mesh', GeometryMesh(surface), promotes=['*'])
            tmp_group.add('def_mesh',
                          TransferDisplacements(surface),
                          promotes=['*'])
            tmp_group.add('vlmgeom', VLMGeometry(surface), promotes=['*'])
            tmp_group.add('spatialbeamstates',
                          SpatialBeamStates(surface),
                          promotes=['*'])
            tmp_group.spatialbeamstates.ln_solver = LinearGaussSeidel()

            name = name_orig + 'group'
            exec(name + ' = tmp_group')
            exec('coupled.add("' + name + '", ' + name + ', promotes=["*"])')

            # Add a loads component to the coupled group
            exec('coupled.add("' + name_orig + 'loads' + '", ' +
                 'TransferLoads(surface)' + ', promotes=["*"])')

            # Add a '_post_solve' group which evaluates the data after solving
            # the coupled system
            tmp_group = Group()

            tmp_group.add('spatialbeamfuncs',
                          SpatialBeamFunctionals(surface),
                          promotes=['*'])
            tmp_group.add('vlmfuncs', VLMFunctionals(surface), promotes=['*'])

            name = name_orig + 'post_solve'
            exec(name + ' = tmp_group')
            exec('root.add("' + name + '", ' + name + ', promotes=["*"])')

        # Add a single 'VLMStates' component for the whole system
        coupled.add('vlmstates',
                    VLMStates(self.surfaces, self.prob_dict),
                    promotes=['*'])

        # Set solver properties for the coupled group
        coupled.ln_solver = ScipyGMRES()
        coupled.ln_solver.options['iprint'] = 1
        coupled.ln_solver.preconditioner = LinearGaussSeidel()
        coupled.vlmstates.ln_solver = LinearGaussSeidel()

        coupled.nl_solver = NLGaussSeidel()
        coupled.nl_solver.options['iprint'] = 1

        # Ensure that the groups are ordered correctly within the coupled group
        order_list = []
        for surface in self.surfaces:
            order_list.append(surface['name'] + 'group')
        order_list.append('vlmstates')
        for surface in self.surfaces:
            order_list.append(surface['name'] + 'loads')
        coupled.set_order(order_list)

        # Add the coupled group to the root problem
        root.add('coupled', coupled, promotes=['*'])

        # Add problem information as an independent variables component
        prob_vars = [('v', self.prob_dict['v']),
                     ('alpha', self.prob_dict['alpha']),
                     ('M', self.prob_dict['M']), ('Re', self.prob_dict['Re']),
                     ('rho', self.prob_dict['rho'])]
        root.add('prob_vars', IndepVarComp(prob_vars), promotes=['*'])

        # Add functionals to evaluate performance of the system
        root.add('fuelburn',
                 FunctionalBreguetRange(self.surfaces, self.prob_dict),
                 promotes=['*'])
        root.add('eq_con',
                 FunctionalEquilibrium(self.surfaces, self.prob_dict),
                 promotes=['*'])

        self.setup_prob()
Exemplo n.º 7
0
    def setup_aero(self):
        """
        Specific method to add the necessary components to the problem for an
        aerodynamic problem.
        """

        # Set the problem name if the user doesn't
        if 'prob_name' not in self.prob_dict.keys():
            self.prob_dict['prob_name'] = 'aero'

        # Create the base root-level group
        root = Group()

        # Create the problem and assign the root group
        self.prob = Problem()
        self.prob.root = root

        # Loop over each surface in the surfaces list
        for surface in self.surfaces:

            # Get the surface name and create a group to contain components
            # only for this surface
            name = surface['name']
            tmp_group = Group()

            # Add independent variables that do not belong to a specific component
            indep_vars = [(name + 'twist_cp',
                           numpy.zeros(surface['num_twist'])),
                          (name + 'dihedral', surface['dihedral']),
                          (name + 'sweep', surface['sweep']),
                          (name + 'span', surface['span']),
                          (name + 'taper', surface['taper']),
                          (name + 'disp', numpy.zeros((surface['num_y'], 6)))]

            # Obtain the Jacobian to interpolate the data from the b-spline
            # control points
            jac_twist = get_bspline_mtx(surface['num_twist'], surface['num_y'])

            # Add aero components to the surface-specific group
            tmp_group.add('indep_vars',
                          IndepVarComp(indep_vars),
                          promotes=['*'])
            tmp_group.add('twist_bsp',
                          Bspline(name + 'twist_cp', name + 'twist',
                                  jac_twist),
                          promotes=['*'])
            tmp_group.add('mesh', GeometryMesh(surface), promotes=['*'])
            tmp_group.add('def_mesh',
                          TransferDisplacements(surface),
                          promotes=['*'])
            tmp_group.add('vlmgeom', VLMGeometry(surface), promotes=['*'])

            # Add tmp_group to the problem with the name of the surface and
            # '_pre_solve' appended.
            # Note that is a '_pre_solve' and '_post_solve' group for each
            # individual surface.
            name_orig = name.strip('_')
            name = name_orig + '_pre_solve'
            exec(name + ' = tmp_group')
            exec('root.add("' + name + '", ' + name + ', promotes=["*"])')

            # Add a '_post_solve' group
            name = name_orig + '_post_solve'
            exec('root.add("' + name + '", ' + 'VLMFunctionals(surface)' +
                 ', promotes=["*"])')

        # Add problem information as an independent variables component
        prob_vars = [('v', self.prob_dict['v']),
                     ('alpha', self.prob_dict['alpha']),
                     ('M', self.prob_dict['M']), ('Re', self.prob_dict['Re']),
                     ('rho', self.prob_dict['rho'])]
        root.add('prob_vars', IndepVarComp(prob_vars), promotes=['*'])

        # Add a single 'VLMStates' component that solves for the circulations
        # and forces from all the surfaces.
        # While other components only depends on a single surface,
        # this component requires information from all surfaces because
        # each surface interacts with the others.
        root.add('vlmstates',
                 VLMStates(self.surfaces, self.prob_dict),
                 promotes=['*'])

        self.setup_prob()