aerosandbox.library.aerodynamics.components =========================================== .. py:module:: aerosandbox.library.aerodynamics.components Functions --------- .. autoapisummary:: aerosandbox.library.aerodynamics.components.CDA_control_linkage aerosandbox.library.aerodynamics.components.CDA_control_surface_gaps aerosandbox.library.aerodynamics.components.CDA_protruding_bolt_or_rivet aerosandbox.library.aerodynamics.components.CDA_perpendicular_sheet_metal_joint Module Contents --------------- .. py:function:: CDA_control_linkage(Re_l, linkage_length, is_covered = False, is_top = False) Computes the drag area (CDA) of a typical control usage as used on a well-manufactured RC airplane. The drag area (CDA) is defined as: CDA == D / q, where: - D is the drag force (dimensionalized, e.g., in Newtons) - q is the freestream dynamic pressure (dimensionalized, e.g., in Pascals) See study with original data at `AeroSandbox/studies/LinkageDrag`. Data from: * Hepperle, Martin. "Drag of Linkages". https://www.mh-aerotools.de/airfoils/linkage.htm * Summarizes data from "Werner Würz, published in the papers of the ISF-Seminar in December 1989 in Baden, Switzerland." :param Re_l: Reynolds number, with reference length as the length of the linkage. :param linkage_length: The length of the linkage. [m] :param is_covered: A boolean of whether an aerodynamic fairing is placed around the linkage. :param is_top: A boolean of whether the linkage is on the top surface of the wing (True) or the bottom surface ( False). Differences in local boundary layer and inviscid effects cause local velocity changes. Returns: The drag area [m^2] of the control linkage. .. py:function:: CDA_control_surface_gaps(local_chord, control_surface_span, local_thickness_over_chord = 0.12, control_surface_hinge_x = 0.75, n_side_gaps = 2, side_gap_width = None, hinge_gap_width = None) Computes the drag area (CDA) of the gaps associated with a typical wing control surface. (E.g., aileron, flap, elevator, rudder). The drag area (CDA) is defined as: CDA == D / q, where: - D is the drag force (dimensionalized, e.g., in Newtons) - q is the freestream dynamic pressure (dimensionalized, e.g., in Pascals) This drag area consists of two sources: 1. Chordwise gaps at the side edges of the control surface ("side gaps") 2. Spanwise gaps at the hinge line of the control surface ("hinge gap") :param local_chord: The local chord of the wing at the midpoint of the control surface. [meters] :param control_surface_span: The span of the control surface. [meters] :param local_thickness_over_chord: The local thickness-to-chord ratio of the wing at the midpoint of the control surface. [nondimensional] For example, this is 0.12 for a NACA0012 airfoil. :param control_surface_hinge_x: The x-location of the hinge line of the control surface, as a fraction of the local chord. [nondimensional] Defaults to x_hinge / c = 0.75, which is typical for an aileron. :param n_side_gaps: The number of "side gaps" to count on this control surface when computing drag. Defaults to 2 ( i.e., one inboard gap, one outboard gap), which is the simplest case of a wing with a single partial-span aileron. However, there may be cases where it is best to reduce this to 1 or 0. For example: * A wing with a single full-span aileron would have 1 side gap (at the wing root, but not at the tip). * A wing with a flap and aileron that share a chordwise gap would be best modeled by setting n_side_gaps = 1 ( so that no double-counting occurs). :param side_gap_width: The width of the chordwise gaps at the side edges of the control surface [meters]. If this is left as the default (None), then a typical value will be computed based on the local chord and control surface span. :param hinge_gap_width: The width of the spanwise gap at the hinge line of the control surface [meters]. If this is left as the default (None), then a typical value will be computed based on the local chord. Returns: The drag area [m^2] of the gaps associated with the control surface. This should be added to the "clean" wing drag to get a more realistic drag estimate. .. py:function:: CDA_protruding_bolt_or_rivet(diameter, kind = 'flush_rivet') Computes the drag area (CDA) of a protruding bolt or rivet. The drag area (CDA) is defined as: CDA == D / q, where: - D is the drag force (dimensionalized, e.g., in Newtons) - q is the freestream dynamic pressure (dimensionalized, e.g., in Pascals) :param diameter: The diameter of the bolt or rivet. [meters] :param kind: The type of bolt or rivet. Valid options are: - "flush_rivet" - "round_rivet" - "flat_head_bolt" - "round_head_bolt" - "cylindrical_bolt" - "hex_bolt" Returns: The drag area [m^2] of the bolt or rivet. .. py:function:: CDA_perpendicular_sheet_metal_joint(joint_width, sheet_metal_thickness, kind = 'butt_joint_with_inside_joiner') Computes the drag area (CDA) of a sheet metal joint that is perpendicular to the flow. (E.g., spanwise on the wing, or circumferential on the fuselage). The drag area (CDA) is defined as: CDA == D / q, where: - D is the drag force (dimensionalized, e.g., in Newtons) - q is the freestream dynamic pressure (dimensionalized, e.g., in Pascals) :param joint_width: The width of the joint (perpendicular to the airflow, e.g., spanwise on a wing). [meters] :param sheet_metal_thickness: The thickness of the sheet metal. [meters] :param kind: The type of joint. Valid options are: - "butt_joint_with_inside_joiner" - "butt_joint_with_inside_weld" - "butt_joint_with_outside_joiner" - "butt_joint_with_outside_weld" - "lap_joint_forward_facing_step" - "lap_joint_backward_facing_step" - "lap_joint_forward_facing_step_with_bevel" - "lap_joint_backward_facing_step_with_bevel" - "lap_joint_forward_facing_step_with_rounded_bevel" - "lap_joint_backward_facing_step_with_rounded_bevel" - "flush_lap_joint_forward_facing_step" - "flush_lap_joint_backward_facing_step" Returns: The drag area [m^2] of the sheet metal joint.