Drain apparatus

A method for draining fluid from an interior region within an aircraft wing and through an exterior of an aircraft, comprising:

• disposing a drain element in an exterior panel of the aircraft wing, wherein the drain element includes:
• an aft end portion;
• an annular connector, wherein the annular connector is to be disposed within a drain port in the exterior of an aircraft, the drain element having a forward end portion with a contoured protrusion disposed over the annular connector;
• and
• a drain opening at the aft end of the contoured protrusion, wherein the contoured protrusion enables fluid flow from the drain port through the annular connector and out the drain opening;
• wherein an airflow across the contoured protrusion creates a reduced pressure region external to the drain opening relative to the pressure at the annular connector and drain port, so as to induce fluid flow from an interior region within an aircraft wing and through the annular connector in the drain port and out the drain opening, and
• wherein the aft end portion of the drain element comprises a globular protrusion positioned aft of the drain opening to inhibit air turbulence at the end of the contoured protrusion, such that flow of an external airstream across the contoured protrusion and the globular protrusion is generally laminar.

A method of fabricating a drain element for drainage of fluid from an interior region within an aircraft wing and through an exterior of an aircraft, comprising:

• forming an aft end portion;
• forming an annular connector, wherein the annular connector is configured to be disposed within a drain port in an exterior panel of the aircraft wing, the drain element having a forward end portion with a contoured protrusion disposed over the annular connector;
• and
• forming a drain opening at the aft end of the contoured protrusion, wherein the contoured protrusion is configured to enable fluid flow from the drain port through the annular connector and out the drain opening;
• wherein an airflow across the contoured protrusion creates a reduced pressure region external to the drain opening relative to the pressure at the annular connector and drain port, so as to induce fluid flow from an interior region within an aircraft wing and through the annular connector in the drain port and out the drain opening, and
• wherein the aft end portion of the drain element comprises a globular protrusion positioned aft of the drain opening to inhibit air turbulence at the end of the contoured protrusion, such that flow of an external airstream across the contoured protrusion and the globular protrusion is generally laminar.