Bilaterally asymmetric design for minimizing wave drag

Patent metadata

Field	Value
Publication number	US-9522727-B2
Application number	US-201514628218-A
Country	US
Kind code	B2
Filing date	Feb 21, 2015
Priority date	Nov 28, 2012
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

An air vehicle may include a body having forwardly-swept fixed wings or unswept fixed wings. The body may have a longitudinal axis continuously oriented parallel to a forward flight direction when the air vehicle is in flight. The air vehicle may include at least one of the following components being mounted on opposite sides of the body: longitudinally offset engine nacelles, asymmetrically lengthened engine nacelles, and longitudinally offset protruding aerodynamic surfaces comprising at least one of stabilizers, canards, empennage control surfaces, external stores, and high aspect ratio wings.

First claim

What is claimed is:

1. An air vehicle having a bilaterally asymmetric configuration, comprising:
a body having forwardly-swept fixed wings or unswept fixed wings, the body having a longitudinal axis continuously oriented parallel to a forward flight direction when the air vehicle is in flight; and
at least one of the following components being mounted on opposite sides of the body:
longitudinally offset engine nacelles;
asymmetrically lengthened engine nacelles; and
longitudinally offset protruding aerodynamic surfaces comprising at least one of stabilizers, canards, empennage control surfaces, external stores, and high aspect ratio wings.

2. The air vehicle of claim 1 , wherein:
the engine nacelles are wing-mounted.

3. The air vehicle of claim 1 , wherein:
an engine inlet of an aft nacelle is aft of the engine inlet of a forward nacelle and forward of a nozzle of the forward nacelle; and
the forward nacelle and the aft nacelle being either the longitudinally offset engine nacelles or the asymmetrically lengthened engine nacelles.

4. The air vehicle of claim 1 , wherein:
a region of decreasing cross-sectional area of a forward nacelle overlaps a region of increasing cross-sectional area of an aft nacelle; and
the forward nacelle and the aft nacelle being either the longitudinally offset engine nacelles or the asymmetrically lengthened engine nacelles.

5. The air vehicle of claim 1 , wherein the asymmetrically lengthened engine nacelles comprise at least one of:
a forward nacelle extension mounted to an engine nacelle on one side of the body; and
an aft nacelle extension mounted to an engine nacelle on an opposite side of the body.

6. The air vehicle of claim 1 , wherein:
the air vehicle comprises an airplane.

7. The air vehicle of claim 1 , wherein:
the air vehicle comprises at least one of a missile, a rocket, and a space vehicle.

8. An air vehicle having a bilaterally asymmetric configuration, comprising:
a body having fixed wings and a longitudinal axis continuously oriented parallel to a forward flight direction when the air vehicle is in flight;
a forward nacelle and an aft nacelle mounted on opposite sides of the body; and
an engine inlet of the aft nacelle being located aft of the engine inlet of the forward nacelle by no more than 20 percent of an engine length of the forward nacelle.

9. The air vehicle of claim 8 , wherein:
the engine inlet of the aft nacelle is located aft of the engine inlet of the forward nacelle by no more than 10 percent of the engine length of the forward nacelle.

10. A method of minimizing wave drag of an air vehicle, comprising the steps of:
providing a body of an air vehicle having forwardly-swept fixed wings or unswept fixed wings, the body having a longitudinal axis continuously oriented parallel to a forward flight direction when the air vehicle is in flight; and
longitudinally offsetting at least one of the following components on opposite sides of the body:
engine nacelles; and
protruding aerodynamic surfaces comprising at least one of stabilizers, canards, empennage control surfaces, external stores, and high aspect ratio wings.

11. The method of claim 10 , wherein:
the engine nacelles are wing-mounted.

12. The method of claim 10 , wherein the step of longitudinally offsetting the engine nacelles comprises:
locating an engine inlet of an aft nacelle aft of the engine inlet of a forward nacelle and forward of a nozzle of the forward nacelle.

13. The method of claim 10 , wherein the step of longitudinally offsetting the engine nacelles comprises:
overlapping a region of decreasing cross-sectional area of a forward nacelle with a region of increasing cross-sectional area of an aft nacelle.

14. The method of claim 10 , wherein the step of longitudinally offsetting the engine nacelles comprises at least one of:
adding a forward nacelle extension to an engine nacelle on one side of the body of an existing air vehicle; and
adding an aft nacelle extension to an engine nacelle on an opposite side of the body of the existing air vehicle.

15. The method of claim 10 , wherein the step of longitudinally offsetting the stabilizers comprises:
longitudinally offsetting at least one of horizontal stabilizers and vertical stabilizers.

16. The method of claim 10 , wherein the step of longitudinally offsetting the external stores comprises:
mounting external stores in a bilaterally symmetrical manner on opposite sides of the body; and
releasing an external store on one side of the body prior to releasing an external store on an opposite side of the body.

17. The method of claim 16 wherein at least one of the external stores comprises at least one of:
a missile, a bomb, and a fuel pod.

18. The method of claim 10 , wherein:
the air vehicle comprises an airplane.

19. A method of minimizing wave drag of an air vehicle, comprising the steps of:
providing a body having fixed wings and a longitudinal axis continuously oriented parallel to a forward flight direction when the air vehicle is in flight;
mounting a forward nacelle and an aft nacelle on opposite sides of the body; and
locating an engine inlet of the aft nacelle aft of the engine inlet of the forward nacelle by no more than 20 percent of an engine length of the forward nacelle.

20. The method of claim 19 , wherein the step of locating the engine inlet comprises:
locating the engine inlet of the aft nacelle aft of the engine inlet of the forward nacelle by no more than 10 percent of the engine length of the forward nacelle.

Assignees

• Boeing Co

Inventors

• Pflug William
• Tillotson Brian J

Classifications

• B64C5/00

  Stabilising surfaces · CPC title

• B64D29/02

  associated with wings · CPC title

• B64C30/00

  Supersonic type aircraft · CPC title

• B64C23/04 Primary

  by generating shock waves · CPC title

• B64C7/02

  Nacelles · CPC title