fastga.models.aerodynamics.external.openvsp.openvsp module

Estimation of cl/cm/oswald aero coefficients using OPENVSP.

class fastga.models.aerodynamics.external.openvsp.openvsp.OpenVSPSimpleGeometry(**kwargs)

Bases: openmdao.components.external_code_comp.ExternalCodeComp

Execution of OpenVSP for clean surfaces.

Intialize the ExternalCodeComp component.

initialize()

Perform any one-time initialization run at instantiation.

setup()

Declare inputs and outputs.

Available attributes:

name pathname comm options

check_config(logger)

Perform optional error checks.

Parameters

logger (object) – The object that manages logging output.

compute_cl_alpha_aircraft(inputs, outputs, altitude, mach, aoa_angle)

Function that perform a complete calculation of aerodynamic parameters under OpenVSP and returns only the cl_alpha_aircraft parameter.

compute_cl_alpha_mach(inputs, outputs, aoa_angle, altitude, cruise_mach)

Function that performs multiple run of OpenVSP to get an interpolation of Cl_alpha as a function of Mach for later use in the computation of the V-n diagram.

compute_aero_coeff(inputs, outputs, altitude, mach, aoa_angle)

Function that computes in OpenVSP environment all the aerodynamic parameters @0° and aoa_angle and calculate the associated derivatives.

@param inputs: inputs parameters defined within FAST-OAD-GA @param outputs: outputs parameters defined within FAST-OAD-GA @param altitude: altitude for aerodynamic calculation in meters @param mach: air speed expressed in mach @param aoa_angle: air speed angle of attack with respect to aircraft @return: cl_0_wing, cl_alpha_wing, cm_0_wing, y_vector_wing, cl_vector_wing, coeff_k_wing, cl_0_htp, cl_aoa_htp, cl_alpha_htp, cl_alpha_htp_isolated, y_vector_htp, cl_vector_htp, coeff_k_htp parameters.

compute_aero(inputs, outputs, altitude, mach, aoa_angle, comp_opt='wing')

Function that computes in OpenVSP environment the wing, horizontal stablizer(htp), and complete aircraft (considering wing and horizontal tail plan) and returns the different aerodynamic parameters. The downwash is done by OpenVSP considering far field.

Parameters

• inputs – inputs parameters defined within FAST-OAD-GA

• outputs – outputs parameters defined within FAST-OAD-GA

• altitude – altitude for aerodynamic calculation in meters

• mach – air speed expressed in mach

• aoa_angle – air speed angle of attack with respect to aircraft

• comp_opt – component to evaluate can be “wing”, “htp” or “ac”

Returns

wing/htp and aircraft dictionaries including their respective aerodynamic

coefficients

static search_results(result_folder_path, geometry_set)

Search the results folder to see if the geometry has already been calculated.

static save_geometry(result_folder_path, geometry_set)

Save geometry if not already computed by finding first available index.

static save_results(result_file_path, results)

Reads saved results.

static read_results(result_file_path)

static define_geometry(inputs, mach)

Extract geometrical parameters

Parameters

• inputs – inputs in the OpenMDAO format

• mach – Mach number

Return s_ref_wing

wing reference surface area

Return area_ratio

rea ratio between wing and horizontal stabilizer

Return s_ref_wing

geometry dataset for openvsp calculation

static post_process_wing(inputs, wing_0, wing_aoa, s_ref_wing, aoa_angle)

Computes wing data not produced by OpenVSP based on available ones

Parameters

• inputs – inputs in the OpenMDAO format

• wing_0 – wing aerodynamic coefficient with 0 angle of attack

• wing_aoa – wing aerodynamic coefficient with input angle of attack

• s_ref_wing – wing reference surface area

• aoa_angle – input angle of attack

Returns

lift coefficient at 0 aoa, lift coefficient at input aoa, lift slope coefficient,

pitching moment coefficient, span vector, lift coefficient vector, chord vector, lift induced drag coefficient

static post_process_htp(htp_0, htp_aoa, htp_0_isolated, htp_aoa_isolated, aoa_angle, area_ratio)

Computes htp data not produced by OpenVSP based on available ones

Parameters

• htp_0 – htp aerodynamic coefficient with 0 angle of attack

• htp_aoa – htp aerodynamic coefficient with input angle of attack

• htp_0_isolated – isolated htp aerodynamic coefficient with 0 angle of attack

• htp_aoa_isolated – isolated htp aerodynamic coefficient with input angle of attack

• aoa_angle – input angle of attack

• area_ratio – ratio between htp reference area and wing reference area

Returns

htp lift coefficient at 0 aoa, htp lift coefficient at input aoa, htp lift slope

coefficient, isolated htp lift slope coefficient, span vector, lift coefficient vector, lift induced drag coefficient

static resize_vector(vectors)

Format the size of results that need to be passed as array to the size declared to OpenMDAO if the original array is bigger we resize it, otherwise we complete with zeros. First vector always has to be the y vector, any other vector can be a quantity expressed as that vector.

Parameters

vectors – a tuple with wing aerodynamic results

Returns

length-modified aerodynamic results

static assign_read_data(data, area_ratio, saved_area_ratio, s_ref_wing)

When results already exists, read and assign existing data and apply the new area ratio

Parameters

• data – existing results under the form of a dataframe

• area_ratio – area ratio between the wing and the horizontal stabilizer

• saved_area_ratio – area ratio between the wing and the horizontal stabilizer in

existing results :param s_ref_wing: wing reference surface area

Returns

aerodynamic characteristic parameters of wing and horizontal stabilizer

class fastga.models.aerodynamics.external.openvsp.openvsp.OpenVSPSimpleGeometryDP(**kwargs)

Bases: fastga.models.aerodynamics.external.openvsp.openvsp.OpenVSPSimpleGeometry

Execution of OpenVSP for surfaces with slipstream effects.

Intialize the ExternalCodeComp component.

initialize()

Perform any one-time initialization run at instantiation.

setup()

Declare inputs and outputs.

Available attributes:

name pathname comm options

compute_wing_rotor(inputs, outputs, altitude, mach, aoa_angle, thrust, power)

Function that computes in OpenVSP environment the wing with a rotor and returns the different aerodynamic parameters.

@param inputs: inputs parameters defined within FAST-OAD-GA @param outputs: outputs parameters defined within FAST-OAD-GA @param altitude: altitude for aerodynamic calculation in meters @param mach: air speed expressed in mach @param aoa_angle: air speed angle of attack with respect to wing (degree) @param thrust: total aircraft thrust for computation of thrust coefficient (will be divided by engine count) @param power: total aircraft power for computation of power coefficient (will be divided by engine count) @return: wing dictionary including aero parameters as keys: y_vector, cl_vector, cd_vector, cm_vector, cl, cdi, cm, coeff_e

fastga.models.aerodynamics.external.openvsp.openvsp.generate_wing_rotor_file(engine_count: int)

Uses the base VSPAERO template file to generate a file with all the line required to launch OpenVSP with n rotors in the run

Parameters

engine_count – the number of engine in the run

return the path to the new template file for the n rotor run.