Blended wing body aircraft

Patent metadata

Field	Value
Publication number	US-11498678-B2
Application number	US-202117176208-A
Country	US
Kind code	B2
Filing date	Feb 16, 2021
Priority date	Dec 9, 2015
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

A blended wing body aircraft wherein at least each profile section corresponding to the normalized half-span values from 0 to 0.2 has a thickness ratio having a nominal value within the range set forth in Table 1. Also, a blended wing body aircraft wherein at least each profile section corresponding to the normalized half-span values from 0.15 to 0.3 has a normalized chord having a nominal value within the range set forth in Table 1, and wherein a ratio between a maximum thickness of the center body and the chord length along the centerline has a nominal value of at least 16%. Also, a blended wing body aircraft wherein a region of the aircraft defined by normalized half-span values from 0.1 to 0.2 has a normalized chord having a dimensionless rate of change from −3.5 to −5.1, and a thickness ratio having a rate of change from −0.27 to −0.72.

First claim

The invention claimed is:

1. A blended wing body aircraft comprising:
an airfoil shaped center body; and
a pair of wings extending from opposed sides of the center body;
wherein the aircraft has a maximum chord length defined longitudinally by the center body;
wherein the aircraft has a span direction, and a maximum half-span length defined along the span direction from a centerline of the center body to a tip of one of the wings;
wherein a normalized half-span value for each profile section of the aircraft is defined by a ratio between a distance along the span direction from the centerline to the profile section, and the maximum half-span length;
wherein a region of the aircraft defined by normalized half-span values from 0.1 to 0.2 has a normalized chord having a dimensionless rate of change from −3.5 to −5.1, the normalized chord being defined by a ratio of a chord length within the region to the maximum chord length, the rate of change of the normalized chord length defined by a dimensionless ratio of a variation in the normalized chord to a variation in the normalized half span value; and
wherein the region of the aircraft defined by the normalized half-span values from 0.1 to 0.2 has a thickness ratio having a rate of change from −0.27 to −0.72, the thickness ratio defined by a ratio of the thickness to the chord length of a same profile section, the rate of change of the thickness ratio defined by a dimensionless ratio of a variation in the thickness ratio to a variation in the normalized half span value.

2. The blended wing body aircraft according to claim 1 , wherein the dimensionless rate of change of the normalized chord in the region defined by the normalized half-span values from 0.1 to 0.2 is from −4.3 to −5.1.

3. The blended wing body aircraft according to claim 1 , wherein the dimensionless rate of change of the normalized chord in a region defined by the normalized half-span values from 0.1 to 0.3 is at least −2.4.

4. The blended wing body aircraft according to claim 1 , wherein the dimensionless rate of change of the thickness ratio in the region defined by the normalized half-span values from 0.1 to 0.2 is from −0.49 to −0.72.

5. The blended wing body aircraft according to claim 1 , wherein the dimensionless rate of change of the thickness ratio in a region defined by the normalized half-span values from 0.1 to 0.3 is at least −0.28.

6. The blended wing body aircraft according to claim 1 , wherein the center body includes an interior cabin having a usable volume of at most 4500 ft 3 .

7. The blended wing body aircraft according to claim 6 , wherein the interior cabin has a maximum length defined longitudinally and a maximum width defined perpendicularly to the maximum length, a cabin aspect ratio of the maximum length to the maximum width being at most 4.

8. The blended wing body aircraft according to claim 1 , wherein a reference line is defined perpendicularly to a direction defined by a maximum thickness of the center body at a mid-point of the maximum thickness, the reference line extending fore-to-aft in relation to the center body, a part of each of the wings having a leading edge located a first distance below the reference line, the first distance being measured along the direction defined by the maximum thickness and corresponding to at least 10% of the maximum thickness.

Assignees

• Bombardier Inc

Inventors

• Banerjee Siddhartho
• Galin Alexandre
• Chittick Ian

Classifications

• Y02T50/10

  Drag reduction · CPC title

• B64C39/10 Primary

  All-wing aircraft · CPC title

• B64C2039/105

  of blended wing body type · CPC title

• B64C3/14

  Aerofoil profile · CPC title

• B64C1/0009

  Aerodynamic aspects · CPC title