Define wing cutouts

[sdeinert]

In order to define cutout holes in the wing structure a cutouts element in CPACS is required. An application for this would be to remove a patch in the wing lower skin to have an opening for the main landing gear. Or removing the wing skin forward and aft of the wing box inside the fuselage in case of a carry through wingbox.

Extending the existing wingComponentSegmentType by an optional wingCutOuts element:

<xsd:element minOccurs="0" name="wingCutOuts" type="wingCutOutsType"/>

of the type wingCutOutsType:

<xsd:complexType name="wingCutOutsType">
    <xsd:annotation>
        <xsd:appinfo>
            <sd:schemaDoc>
                <ddue:summary>
                    <ddue:para>CutOuts of the wing.</ddue:para>
                </ddue:summary>
                <ddue:remarks>
                    <ddue:para>WingCutOuts type, containing all the cutouts of the wing.
                    </ddue:para>
                </ddue:remarks>
            </sd:schemaDoc>
        </xsd:appinfo>
    </xsd:annotation>
    <xsd:complexContent>
        <xsd:extension base="complexBaseType">
            <xsd:sequence>
                <xsd:element maxOccurs="unbounded" name="cutOut" type="wingCutOutType"/>
            </xsd:sequence>
        </xsd:extension>
    </xsd:complexContent>
</xsd:complexType>

which contains a list of cutout definitions wingCutOutType that re-use the logic of a wing cell definition based on four border references. Additionally the cutout side needs to be specified, whether the upper, lower or both sides of the wing skin are affected by the cutout.

<xsd:complexType name="wingCutOutType">
    <xsd:annotation>
        <xsd:appinfo>
            <sd:schemaDoc>
                <ddue:summary>
                    <ddue:para>Cell of the wing</ddue:para>
                </ddue:summary>
                <ddue:remarks>
                    <ddue:content>
                        <ddue:para>A wing cutout is defined using any combination of eta-xsi-spar-rib-uids.
                            It has the similar syntax to a wingCell.
                        </ddue:para>
                        <ddue:para>The cell leading and trailing edge (= forward and rear
                            border) can either be defined by referencing to a spar
                            (-&gt;sparUID) or by the defining the xsi (=relative chord)
                            coordinates of the border (xsi1 = inner end; xsi2 = outer end).
                        </ddue:para>
                        <ddue:para>The cell inner and outer border can either be defined
                            by referencing to a rib (-&gt;ribDefinitionUID and ribNumber) or
                            by the defining the eta (=relative spanwise) coordinates of the
                            border (eta1 = forward end; eta2 = rear end).</ddue:para>
                        <ddue:para>Some examples for wing cells can be found in the
                            picture below:</ddue:para>
                        <ddue:mediaLink>
                            <ddue:image xlink:href="cells"/>
                        </ddue:mediaLink>
                    </ddue:content>
                </ddue:remarks>
            </sd:schemaDoc>
        </xsd:appinfo>
    </xsd:annotation>
    <xsd:complexContent>
        <xsd:extension base="complexBaseType">
            <xsd:sequence>
                <xsd:element name="positioningLeadingEdge" type="cellPositioningChordwiseType"/>
                <xsd:element name="positioningTrailingEdge" type="cellPositioningChordwiseType"/>
                <xsd:element name="positioningInnerBorder" type="cellPositioningSpanwiseType"/>
                <xsd:element name="positioningOuterBorder" type="cellPositioningSpanwiseType"/>
                <xsd:element name="cutOutSidesType">
                    <xsd:annotation>
                        <xsd:documentation>Type of the cutout: upper shell, lower shell or both.
                        </xsd:documentation>
                    </xsd:annotation>
                    <xsd:complexType>
                        <xsd:simpleContent>
                            <xsd:restriction base="stringBaseType">
                                <xsd:enumeration value="upper"/>
                                <xsd:enumeration value="lower"/>
                                <xsd:enumeration value="both"/>
                            </xsd:restriction>
                        </xsd:simpleContent>
                    </xsd:complexType>
                </xsd:element>
            </xsd:sequence>
            <xsd:attribute name="uID" type="xsd:string" use="required"/>
        </xsd:extension>
    </xsd:complexContent>
</xsd:complexType>

[MarAlder]

Thank you for the extension. wingComponentSegmentType does not directly exist in CPACS. I guess it should be part of wingComponentSegmentStructureType?

[sdeinert]

Yes, you are right, it should be moved to wingComponentSegmentStructureType.

Below you can see a screenshot of two wing cutouts.

• The first one is removing upper and lower skin from leading edge to front spar
• The second one cuts a hole into the upper skin at some given eta/xsi positions

For both cases the wing symmetry is applied.

I send you the corresponding CPACS file, as I can't figure out how to upload it here.

[MarAlder]

General agreement on the last stakeholder meeting; no further feedback here. So I will close this topic.