BOTTOM DISCHARGE DRAINMAST FOR AN AIRCRAFT

• US 20020088901A1
• Filed: 01/08/2001
• Published: 07/11/2002
• Est. Priority Date: 10/12/2000
• Status: Active Grant

• Current Assignee: Goodrich Corporation (Rtx Corporation)
• Original Assignee: Goodrich Corporation (Rtx Corporation)
• Inventors: Moreland, Thomas R.
• Granted Patent: US 6,425,554 B1
• Time in Patent Office: Days
• US Class Current: 244/136
• CPC Class Codes: B64C 1/1453 Drain masts
• CPC Class Codes: B64D 11/02 Toilet fittings of general application A47K

Abstract

A drainmast (10) for discharging liquid from a moving aircraft (12). The drainmast (10) includes a fairing (20) having a mounting flange (24), a flow-controlling cap (26), and an aerodynamically advantageous mast (28) extending therebetween. The flow-controlling cap (26) has a lower surface defining an airflow-redirecting zone, a liquid-release zone, and a liquid-recirculation zone. The redirecting zone is shaped to redirect airflow (A) into the release zone in a direction parallel to the discharge direction (D) of the drain tube (22). The release zone is shaped to encourage the redirected airflow (A_redir) to sweep a substantial portion of the released liquid away from the fairing in a primary flow path (L). The recirculation zone captures escaped liquid from the release zone and recirculates this escaped liquid back into the release zone in recirculation flow path (L_rec1). The rear and side surfaces of the cap (26) may include a continuous groove (66) aligned with the airflow direction A. The groove (66) defines a second recirculation zone which captures liquid escaping from the primary flow path upstream of the recirculation zone and/or liquid escaping from the first recirculation zone, and which directs the captured liquid into a secondary flow path (L_sec), into the primary flow path (L), and/or into the first recirculation zone.

Claims

1. A drainmast for discharging liquid from a moving aircraft, comprising a fairing and a drain tube within the fairing;

the fairing including a mounting flange, a flow-controlling cap, and a mast extending therebetween;

the mounting flange being adapted for attachment to the aircraft;

the mast being aerodynamically advantageously shaped relative to an expected airflow direction;

the flow-controlling cap having a lower surface defining an aft airflow-redirecting zone, a liquid-release zone forward of the airflow-redirecting zone, and a fore liquid-recirculation zone;

the drain tube including an inlet adapted for connection to an waste water exit line of the aircraft and an outlet positioned to release liquid in a discharge direction into the liquid-release zone;

the redirecting zone being shaped to redirect the airflow into the release zone in a direction parallel to the discharge direction;

the release zone being shaped to encourage the redirected airflow to sweep a substantial portion of the released liquid away from the fairing in a primary flow path; and

the recirculation zone being shaped to capture escaped liquid from the release zone and to recirculate the escaped liquid back into the release zone.

2. A drainmast as set forth in claim 1, wherein the lower surface of the flow-controlling cap includes an aft concave portion defining the airflow redirecting zone, a fore convex portion defining the liquid-recirculating zone, and a transition portion therebetween defining the liquid-release zone.

3. A drainmast as set forth in claim 1, wherein the drain tube is shaped and positioned so that the discharge direction is at a 45°

to 90°

downward angle relative to the expected airflow direction.

4. A drainmast as set forth in claim 3, wherein the drain tube is shaped and positioned so that the discharge direction is at a 45°

to 75°

downward angle relative to the expected airflow direction.

5. A drainmast as set forth in claim 4, wherein the drain tube is shaped and positioned so that the discharge direction is at a 45°

to 60°

downward angle relative to the expected airflow direction.

6. A drainmast as set forth in claim 1, wherein the fairing'"'"'s flow-controlling portion has rear and side surfaces defining a second recirculation zone which is shaped to capture liquid which escapes from the primary flow path upstream of the recirculation zone and/or liquid which escapes from the lower recirculation zone.

7. A drainmast as set forth in claim 6, wherein the second recirculation zone is shaped to direct the captured liquid into a secondary flow path, into the primary flow path, and/or into the first recirculation zone.

8. A drainmast as set forth in claim 7, wherein the second recirculation zone comprises a continuous groove formed in the rear and side surfaces.

9. A drainmast as set forth in claim 8, wherein the groove is positioned parallel to the expected airflow direction.

10. A drainmast as set forth in claim 1, wherein the cap comprises:

an aft portion having a convex shape when viewed from the side and a half-oval shape when viewed from the bottom;

a fore portion having a concave shape when viewed from the side and a parabola shape when viewed from the bottom; and

a transition portion therebetween having a trapezoid shape when viewed from the side and a roughly rectangular shape when viewed from the bottom;

wherein the aft portion defines the airflow redirecting zone, the fore portion defines the liquid-recirculating zone, and the transition portion defines the liquid-release zone.

11. In combination, an aircraft, and the drainmast of claim 1 mounted to the aircraft.

13. A method as set forth in claim 12, further comprising the steps of capturing liquid which escapes from the primary flow path upstream of the first recirculation zone and/or liquid which escapes from the first recirculation zone in a second recirculation zone.

14. A method as set forth in claim 13, further comprising the steps of directing the liquid from the second recirculation zone into a secondary flow path, into the primary flow path, and/or into the first recirculation zone.

16. A drainmast as set forth in claim 15, wherein the lower surface of the fairing includes an aft convex portion defining the airflow redirecting zone.

17. A drainmast as set forth in claim 16, wherein the lower surface of the fairing includes a fore concave portion defining the liquid-recirculating zone.

18. A drainmast as set forth in claim 17, wherein the lower surface of the fairing including a transition portion between the convex portion and the concave portion and wherein this transition portion defines the liquid-release zone.

19. A drainmast as set forth in claim 15, wherein the fairing has rear and side surfaces defining the recirculation zone.

20. A drainmast as set forth in claim 19, wherein the recirculation zone comprises a continuous groove in the front and side surfaces.

21. A drainmast as set forth in claim 20, wherein the groove is positioned parallel to the expected airflow direction.

12. A method of discharging fluid from a moving aircraft, said method comprising the steps of:

discharging liquid from a drain tube in a discharge direction into a release zone;

redirecting airflow into the release zone in a direction substantially parallel to the discharge direction;

sweeping a substantial portion of the released liquid away from the aircraft in a primary flow path; and

capturing liquid which escapes from the release zone in a first recirculation zone; and

recirculating the escaped liquid back into the release zone whereby it may be swept way from the aircraft in the primary flow path.

15. A drainmast for discharging liquid from a moving aircraft, comprising a fairing and a drain tube within the fairing;

the fairing defining an airflow-redirecting zone, a liquid-release zone, and liquid-recirculation zone;

the drain tube including an inlet adapted for connection to an exit line of a waste water system of the aircraft and an outlet positioned to release liquid in a discharge direction into the liquid-release zone;

the airflow-redirecting zone being shaped and positioned to redirect the airflow into the release zone in a direction parallel to the discharge direction;

the liquid-release zone being shaped and positioned to encourage the redirected airflow to sweep a substantial portion of the released liquid away from the fairing in a primary flow path; and

the liquid-recirculation zone being shaped and positioned to capture escaped liquid and recirculate it back into the primary flow path.

22. A drainmast for discharging liquid from a moving aircraft, comprising a fairing and a drain tube within the fairing;

the fairing defining an airflow-redirecting zone, a liquid-release zone, a first liquid-recirculation zone, and a second liquid-recirculation zone;

the drain tube including an inlet adapted for connection to an exit line of a waste water system of the aircraft and an outlet positioned to release liquid in a discharge direction into the liquid-release zone;

the airflow-redirecting zone being shaped and positioned to redirect the airflow into the release zone in a direction parallel to the discharge direction;

the liquid-release zone being shaped and positioned to encourage the redirected airflow to sweep the released liquid away from the fairing in a primary flow path; and

the liquid-recirculation zones being shaped and positioned to capture liquid which escapes from the primary flow path and recirculate it back into the primary flow path.