DRAINAGE MAST OF THE COMPARTMENT OF THE AUXILIARY POWER UNIT OF AN AIRCRAFT

• US 20130193271A1
• Filed: 04/23/2012
• Published: 08/01/2013
• Est. Priority Date: 01/26/2012
• Status: Active Grant

• Current Assignee: Airbus Operations SL (Airbus SE)
• Original Assignee: Airbus Operations SL (Airbus SE)
• Inventors: OTERO, Jose Grana, Fabian, Ignacio Esteban Parra, Montero, Carlos Casado
• Granted Patent: US 9,321,520 B2
• Time in Patent Office: Days
• US Class Current: 244/136
• CPC Class Codes: B64C 1/1453 Drain masts
• CPC Class Codes: B64D 2041/002 Mounting arrangements for auxiliary power units (APU's)

Abstract

A drainage mast (13) for draining liquids from an APU compartment (11) of an aircraft with a first end (15) connected to the APU compartment (11) and a second end (17) for discharging said liquids to the atmosphere. The drainage mast (13) is configured with at least a sector having decreasing cross section areas towards the second end (17). The area of the initial cross section of said sector is lesser than the area of any cross section of the drainage mast (13) closer to the first end (15). The invention also refers to an aircraft comprising the drainage mast (13).

Claims

1. A drainage mast (13) for draining liquids from an APU compartment (11) of an aircraft with a first end (15) connected to the APU compartment (11) and a second end (17) for discharging said liquids to the atmosphere, characterized in that the drainage mast (13) is configured with at least a sector having decreasing cross section areas towards the second end (17) and in that the area of the initial cross section of said sector is lesser than the area of any cross section of the drainage mast (13) closer to the first end (15).

2. A drainage mast (13) according to claim 1, wherein the whole drainage mast (13) has a decreasing cross section area towards the second end (17).

3. A drainage mast (13) according to claim 1, wherein the drainage mast (13) is configured with an elbow shape in the airflow direction and wherein said sector is the end branch (51).

4. A drainage mast (13) according to claim 1, wherein said sector is an outlet sector (21) at the end of the drainage mast (13).

5. A drainage mast (13) according to claim 4, wherein the drainage mast (13) is arranged at an acute angle (a) with respect to a horizontal plane at said first end (15) in the airflow direction.

6. A drainage mast (13) according to claim 5, wherein said outlet sector (21) comprises an inner obstruction (31, 33).

7. A drainage mast (13) according to claim 6, wherein the inner obstruction (31) completely obstructs a fraction of the cross sections along the lower wall (20) of the outlet sector (21).

8. A drainage mast (13) according to claim 7, wherein the ratio between the areas of the final and the initial cross section of the outlet sector (21) is comprised between 0.5-0.8.

9. A drainage mast (13) according to claim 6, wherein the inner obstruction (33) divides the outlet sector (21) into an upper outlet sub-sector (41), right below the upper wall, and a lower outlet sub-sector (43), right above the lower wall.

10. A drainage mast (13) according to claim 9, wherein the ratio between the areas of the final and the initial cross section of the upper outlet sub-sector (41) and the lower outlet sub-sector (43) is comprised between 0.2-0.4.

11. A drainage mast (13) according to claim 10, wherein said inner obstruction (33) has a conical shape and is arranged with its base in a central position of the outlet sector (21) on the second end (17).

12. A drainage mast (13) according to claim 4, wherein the outlet sector (21) is configured with a nozzle streamlined shape so that the streamlines of the liquid in the second end (17) are very closely parallel to the axis of the drainage mast (13).

13. A drainage mast (13) according to claim 12, wherein the outlet sector (21) has a dome-ended rectangular shape at the second end (17) or oval shape at the second end (17).

14. A drainage mast (13) according to claim 13, wherein the ratio between the effective diameter De of the final cross section and the diameter D of the initial cross section of the outlet sector (21) is comprised between 0.8-0.9 and/or wherein the ratio between the areas of final and the initial cross section of the outlet sector (21) is comprised between 0.6-0.8.

15. An aircraft comprising a drainage mast (13), according to any of claims 1-14.