Disclosed are systems and methods for maintaining bulk fuel temperatures in an aircraft. In one aspect, a recirculation system causes fuel to be delivered from a relatively low point near the feed hopper of each tank on the aircraft to one or more outboard locations of the wings. Once there, the fuel, due to gravity, flows back over the lower skin of the wing in channels back towards the fuselage, thus cooling the fuel. In other aspects, control systems are disclosed that coordinate the recirculation based on fuel levels in the tanks and fuel temperatures. The control systems also utilize a fuel scavenge system to maintain acceptable temperatures in the tanks.

Disclosed are systems and methods for maintaining bulk fuel temperatures in an aircraft. In one aspect, a recirculation system causes fuel to be delivered from a relatively low point near the feed hopper of each tank on the aircraft to one or more outboard locations of the wings. Once there, the fuel, due to gravity, flows back over the lower skin of the wing in channels back towards the fuselage, thus cooling the fuel. In other aspects, control systems are disclosed that coordinate the recirculation based on fuel levels in the tanks and fuel temperatures. The control systems also utilize a fuel scavenge system to maintain acceptable temperatures in the tanks.

Fluid systems are described herein. An example embodiment of a fluid system has a first body portion, a second body portion, a plurality of supports, a plurality of fluid pressurizers, and a plurality of ducts. The first body portion and the second body portion cooperatively define an injection opening, a suction opening, and a channel that extends from the injection opening to the suction opening. The fluid pressurizer is disposed within the channel cooperatively defined by the first body portion and the second body portion. Each duct of the plurality of ducts is disposed within the channel cooperatively defined by the first body portion and the second body portion.

An aircraft and an aircraft wing assembly for an aircraft. The wing assembly includes a wing body assembly including a wing body; and at least one protruding portion connected to the wing body. The protruding portion extends aftwardly from an aft side of the wing body assembly, a leading edge of the wing body assembly defining a leading edge line, a trailing edge of the wing body assembly defining a trailing edge line extending between the inboard end and the outboard end, the trailing edge including a trailing edge of the protruding portion, the trailing edge line being a smooth line, a chord distance being defined longitudinally from the leading edge line to the trailing edge line, the chord distance at a center of the protruding portion being greater than the chord distance inboard of protruding portion and outboard of the protruding portion.

An aircraft and an aircraft wing assembly for an aircraft. The wing assembly includes a wing body assembly including a wing body; and at least one protruding portion connected to the wing body. The protruding portion extends aftwardly from an aft side of the wing body assembly, a leading edge of the wing body assembly defining a leading edge line, a trailing edge of the wing body assembly defining a trailing edge line extending between the inboard end and the outboard end, the trailing edge including a trailing edge of the protruding portion, the trailing edge line being a smooth line, a chord distance being defined longitudinally from the leading edge line to the trailing edge line, the chord distance at a center of the protruding portion being greater than the chord distance inboard of protruding portion and outboard of the protruding portion.

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.

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.

A blended wing body aircraft having an interior cabin with a usable volume of at most 4500 ft.sup.3 and a cabin aspect ratio of at most 4, wherein a combination of the wings and center body has a wetted aspect ratio of at least 1.7 and at most 2.8. Also, a blended wing body aircraft having an interior cabin with a usable volume of at least 1500 ft.sup.3 and at most 4500 ft.sup.3 and a cabin aspect ratio of at least 2 and at most 4, wherein a combination of the wings and center body has a wetted aspect ratio of at least 1.9 and at most 2.7. Also, a blended wing body aircraft wherein at least each profile section having normalized half-span values from 0 to 0.3 has a leading edge having a normalized height having a nominal value within the range set forth in Table 4.

A blended wing body aircraft having an interior cabin with a usable volume of at most 4500 ft.sup.3 and a cabin aspect ratio of at most 4, wherein a combination of the wings and center body has a wetted aspect ratio of at least 1.7 and at most 2.8. Also, a blended wing body aircraft having an interior cabin with a usable volume of at least 1500 ft.sup.3 and at most 4500 ft.sup.3 and a cabin aspect ratio of at least 2 and at most 4, wherein a combination of the wings and center body has a wetted aspect ratio of at least 1.9 and at most 2.7. Also, a blended wing body aircraft wherein at least each profile section having normalized half-span values from 0 to 0.3 has a leading edge having a normalized height having a nominal value within the range set forth in Table 4.

Fluid systems are described herein. An example embodiment of a fluid system has a first body portion, a second body portion, a plurality of supports, a plurality of fluid pressurizers, and a plurality of ducts. The first body portion and the second body portion cooperatively define an injection opening, a suction opening, and a channel that extends from the injection opening to the suction opening. The fluid pressurizer is disposed within the channel cooperatively defined by the first body portion and the second body portion. Each duct of the plurality of ducts is disposed within the channel cooperatively defined by the first body portion and the second body portion.