Aircraft nacelle having electric motor and thrust reversing air exhaust flaps

An aircraft having a fuselage with a nose and a flat tail at opposite ends and a pair of wings extending therefrom. A pair of nacelles are detachably connected to the top of respective ones of the wings to be spaced from the fuselage to establish an air flow space therebetween. Each wing-mounted nacelle includes a plurality of fans, a corresponding plurality of electric motors to drive the fans, and dividers that separate the fans from one another. Each wing-mounted nacelle also includes a pair of rotatable air inlet slats at an air intake end and a pair of rotatable air exhaust flaps at an air exhaust end that are rotated relative to one another to control horizontal propulsive thrust, thrust vectoring and thrust reversing of the aircraft. A third nacelle is mounted on top of the flat tail of the fuselage between a pair of horizontal turbo generators.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a pair of airfoil-shaped, rectangular and multi-functional nacelles each of which having a plurality of horizontally extending electric motors and motor driven fans and being mounted on the top of and lying above respective ones of a pair of wings of an aircraft. The nacelles have rotatable air flow control surfaces at opposite air intake and, exhaust ends thereof to provide the aircraft with enhanced horizontal propulsive thrust, thrust vectoring and thrust reversing.

2. Background Art

Aircraft propulsion systems currently consist of large round nacelles carried underneath the aircraft wing. As engines and nacelles grow larger in diameter, they require moving the wing upward or increasing the length of the landing gear to provide increased ground clearance. The larger nacelles have more surface area which produces more drag. The round nacelle also takes up space along the lateral wing surface that inhibits its use for high lift. Consequently, the advantages of larger nacelles are offset, by increased drag and installation constraints. In addition, when one of the large engines fails, there is an increased yaw moment that is caused by drag on the nacelle, and a large vertical tail and rudder are required to offset the yawing moment. A large circular inlet is also easier to ingest a bird and suffer damage.

SUMMARY OF THE INVENTION

Disclosed herein is an aircraft including a fuselage having a round nose at the front end, a tapered blown pitch flap at the opposite aft end, and a pair of outwardly extending wings. As an important feature of this invention, a pair of rectangular, multi-function nacelles are detachably connected to respective ones of the wings so as to be held entirely above the wings. The nacelles are positioned atop the wings so as to be spaced away from the fuselage and thereby establish air flow paths along the inboard wing between the fuselage and the nacelles by which to reduce air turbulence flowing into the nacelles when the aircraft is in flight.

Each of the pair of rectangular nacelles has a narrow air intake end, an opposite narrow air exhaust end, and a plurality of electric motors and motor driven fans extending horizontally between the air intake and exhaust ends. Divider walls run horizontally through the nacelle between pairs of the fans and motors to prevent incoming air from spilling between the fans. Each nacelle includes an air flow duct between movable air flow control surfaces that are located at the air intake and air exhaust ends of the nacelle by which to enable the aircraft to be provided with enhanced horizontal propulsive thrust, thrust vectoring and thrust reversing.

In particular, upper and lower air inlet slats at the air intake end of the nacelle are rotatable downwardly relative to the air flow duct to increase lift of the aircraft during takeoff. Upper and lower air exhaust flaps at the air exhaust end of the nacelle are rotatable upwardly or downwardly relative to the air flow duct to either slow the speed of the aircraft while landing or increase lift during takeoff. An intermediate air exhaust guide that is located between the air flow duct and the upper air exhaust flap of the nacelle is rotatable upwardly relative to the air flow duct to also slow the aircraft during landing. Upper and lower exhaust diverter flaps that are located between the upper and lower air exhaust flaps at the air exhaust end of the nacelle are rotatable relative to the air exhaust flaps to further slow the aircraft during landing or increase lift during takeoff.

Mounted on the top of the flat tail of the fuselage of the aircraft is a generally rectangular rear boundary layer nacelle. The rear nacelle is located between a pair of turbo generators which are held outwardly from the tail of the fuselage by respective horizontal tail sections. The rear nacelle has a plurality of fans and electric motors extending horizontally therethrough and rotatable yaw vanes located behind the fans and the motors. The rear nacelle and the pair of turbo generators are preferably located behind both the pressure bulkhead and the pressurized passenger cabin of the aircraft to avoid damage to the passenger cabin in the event of a rotor burst.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially toFIGS. 1-3of the drawings, there is shown an aircraft1including a fuselage3hashing a round nose and a flat tapered tail, a pair of horizontal wings5extending outwardly and in opposite directions from the fuselage3, a pair of horizontal tail sections7extending outwardly and in opposite directions from the tail of the fuselage3, a pan of aft turbo generators9carried at the outside ends of respective ones of the tail sections7, and elevator flaps10that are pivotally connected to the rear of respective ones of the tail sections7. As an important improvement to the aircraft1of this invention relative to a conventional aircraft, the aircraft includes an airfoil-shaped, generally rectangular, and multi-function nacelle12that is mounted on the top of each wing5and a generally rectangular boundary layer nacelle14that is mounted on the top of the tail of the fuselage3between the turbo generators9. As will be disclosed in greater detail hereinafter, the multi-function, wing mounted nacelles1have movable control surfaces that are adapted to provide the aircraft1with enhanced horizontal propulsive thrust, thrust vectoring and thrust reversing.

Each of the pair of multi-function nacelles12is mounted on respective ones of the pair of wings5of the aircraft1so as to be held above the top of the wings and positioned to avoid interference that might be caused by the wings so as to enable the nacelle to receive the maximum inflow of air. As one important feature, the nacelles12are mounted on the wings5so as to be spaced outwardly and away from the sides of the fuselage3. Accordingly, an air flow path16(best shown inFIG. 1) is established along the inboard wing through a space18that is created between the fuselage3and each nacelle12. By virtue of the foregoing, air turbulence that is experienced by the aircraft is advantageously minimized.

Turning now toFIGS. 4-6of the drawings, details of each of the pair of identical above-wing mounted nacelles12are now provided. Each nacelle12includes a narrow air intake end, an opposite narrow air exhaust end, and a plurality of (e.g., five) electric motors20that are arranged side-by-side in spaced parallel alignment with one another. A fan22is mounted behind the air intake end of the nacelle12to be driven by a respective one of the electric motors20. Each successive pair of motors20and fans22run horizontally through the nacelle12to be separated from one another by a horizontally extending divider wall24to prevent the air that flows into the air intake end of the nacelle12from spilling between the adjacent fans22.

As will now be explained while referring toFIGS. 7-9of the drawings, each above-wing mounted nacelle12also includes a pair of movable upper and lower air inlet slats26and28located at the air intake end thereof and a pair of movable upper and lower air exhaust flaps30and32located at the air exhaust end. The air inlet slats26and28and the air exhaust flaps30and32cooperate with the fan divider walls24so that the incoming air flowing through each rectangular nacelle12initially enters the inlet slats26and28in a generally rectangular shape, is transformed to a generally round shape by the divider walls24, and is then converted back to a generally rectangular shape by the divider walls to be exhausted to the atmosphere by way of the exhaust flaps30and32.

Each of the upper and lower air inlet slats26and28and the upper and lower air exhaust flaps30and32of each multi-function, wing mounted nacelle12is rotatable so as to cooperate with conventional wing control surfaces and thereby advantageously control the aerodynamic lift, horizontal propulsive thrust, thrust vectoring and thrust reversing of the aircraft1. Each one of the nacelles12as shown inFIGS. 7-9has a flow-through, aero dynamically curved duct36that is located between the air inlet slats26and28and the air exhaust flaps30and32and encloses the motors and the fans (only one motor and one fan20and22being shown). Each flow-through duct36is connected to one of the pair of wings5at the front and rear wing spars38and40thereof so that the nacelle12is mounted on the top of and above the wing5to receive and exhaust air in the manner just explained. A rotatable intermediate air exhaust slat34is positioned between the air flow duct36and the upper air exhaust flap30so that the upper air exhaust flap30extends rearwardly of the lower air exhaust flap32.

More particularly,FIG. 7shows the nacelle12connected to the wing5with the rotatable air inlet slats26and28and the air exhaust flaps30and32positioned relative to one another when the nacelle is in a cruise position with the aircraft flying level and maintaining a desired altitude. In this case, the upper and lower air inlet slats26and28at the air intake end of the nacelle12are horizontal and stationary and lie in generally axial alignment with the upper and lower air exhaust flaps30and32and the air exhaust slat34that are horizontal and stationary at the air exhaust end of the nacelle. Moreover, a rotatable aft exhaust air diverter42that is surrounded by the air exhaust flaps30and32also remains stationary and aligned parallel to flaps30and32. Therefore, all of the incoming air is directed in a straight air exhaust path41through the flow-through duct36and into the motors20, from which it is exhausted through the upper and lower air exhaust flaps30and32to the atmosphere.

FIG. 8shows the air inlet slats26and28, the air exhaust flaps30and32, and the intermediate air exhaust slat34positioned relative to one another, whereby the nacelle12is now in a thrust reversing position when it is necessary to slow the speed of the aircraft while landing without using the brakes. In this case, the rotatable air inlet slats26and28at the air intake end of the nacelle12remain horizontal and stationary. However, each of the upper air exhaust flap30and the intermediate air exhaust slat34are rotated upwardly at respective pivots46and48. Likewise, a rotatable upper exhaust diverter flap50of the aft exhaust air diverter42is rotated upwardly at a pivot54, and a rotatable lower exhaust diverter flap52of the aft exhaust air diverter42is rotated downwardly at the pivot54and away from the upper flap50. What is more, the rotatable lower air exhaust flap32is rotated downwardly at a pivot56, such that the pair of upper and lower air exhaust flaps30and32at the air exhaust end of the nacelle12extend in opposite directions.

Accordingly, a first portion of the air that enters the nacelle12through the air inlet slats26and28and flows into the motors20and fans22that are enclosed by the flow-through duct36is exhausted to the atmosphere in an upward direction by way of a first air exhaust path58that runs between the upturned intermediate air exhaust slat34and each of the similarly upturned upper air exhaust flap30and upper exhaust diverter flap50. The remaining air that enters the nacelle12is exhausted to the atmosphere in a downward direction by way of a second air exhaust path60that runs between the downturned lower, air exhaust flap32and the similarly downturned lower exhaust diverter flap52.

FIG. 9shows the air inlet slats26and28, the air exhaust flaps30and32, the intermediate air exhaust slat34, and the aft exhaust air diverter42repositioned relative to one another, whereby the nacelle12is now in position for taking off. In this case, each of the upper and lower air inlet slats26and28at the air intake end of the nacelle is rotated downwardly at respective pivots62and64so as to be positioned in spaced parallel alignment with one another and parallel to the ground during takeoff. Likewise, each of the upper and lower air exhaust flaps30and32at the air exhaust end of the nacelle12is rotated downwardly at their pivots46and56towards the ground so as to also be positioned in parallel alignment with one another. However, the intermediate air exhaust slat34remains stationary relative to and axially aligned with the flow-through duct36. The upper and lower exhaust diverter flaps50and52of the aft exhaust air diverter42are simultaneously rotated at their pivot54to also face downwardly and lie between and in parallel alignment with the downturned upper and lower air exhaust flaps30and32. The upper and lower exhaust diverter flaps50and52of air diverter42now lie face-to-face with respect to one another so that air will flow smoothly thereover to the atmosphere.

Accordingly, the air that enters the air intake end of the nacelle12through the downturned upper and lower air inlet slats26and28and flows into the motors20and fans22is exhausted from the air exhaust end of the nacelle to the atmosphere in a downward direction towards the ground by way of air exhaust paths66that run along, the downturned aft exhaust air diverter42and between the similarly downturned upper and lower air exhaust flaps30and32.

It may be appreciated that by moving (i.e., rotating) the upper and lower air inlet slats26and28at the air intake end of the nacelle12, the direction of the air flowing into the nacelle12to the motors20and fans22can be selectively adjusted and thereby tailored to achieve an optimum air flow depending upon whether the aircraft1is taking off, landing or simply cruising at altitude. Similarly, the air being exhausted from the air exhaust end of the nacelle12can be selectively adjusted by rotating the upper and lower air exhaust flaps30and32, the intermediate air exhaust slat34, and the upper and lower exhaust diverter flaps50and52at their respective pivots46,48,56and54. In this regard, and by way of example, each of the aforementioned pivots may include a horizontally extending actuator controlled shaft (designated68inFIG. 6).

FIG. 10of the drawings illustrates the detachable nature of the rectangular, multi function nacelle12of this invention with respect to one of the wings5on top of which the nacelle is mounted and detachably connected. As previously described, each nacelle12is detachably connected to a wing5of the aircraft adjacent to the front and rear wing spars38and40. A fairing cover plate70is aerodynamically shaped to cover the joint at the interface of the nacelle12with the front of the wing5to which the nacelle is detachably connected. By virtue of the nacelle12being mounted so as to lie completely above the wing5, it will be easily accessible for service. That is, the nacelle12can be detached from the wing spars38and40for repair and/or replacement without having to disassemble any portion of the wing or remove the entire wing from the aircraft.

FIGS. 11 and 12of the drawings illustrate details of the rear boundary layer nacelle14that is mounted on top of the tail of the fuselage3of the aircraft1so as to be positioned behind and spaced from both the pressure bulkhead72and the pressurized passenger cabin of the fuselage3. As is best shown inFIG. 12, the tail of the fuselage3upon which the rear nacelle14is seated terminates at a flat, inwardly tapered blown pitch flap88that is rotatable up and down around a pivot90in order to control the vertical pitch of the fuselage nose. The rear nacelle14is affixed to and stands upwardly from the flat blown pitch flap88at the aft end of the fuselage3to lie between the aft turbo generators9(best shown inFIGS. 3 and 11). The horizontal tail sections7of the aircraft1at which the turbo generators9are carried run continuously and laterally through the aft tail below the rear boundary layer nacelle14.

As in the case of the above-wing mounted nacelles12, the rear boundary layer tail-mounted nacelle14includes a flow-through duct74through which air flows. The flow-through duct74surrounds a plurality of (e.g., four) electric motors76having respective fans78located in front of each. The electric motors76which drive the fans78are powered by the turbo generators9that are spaced outwardly from the fuselage3by the tail sections7. Each successive pair of motors76and fans78is separated by a divider wall80to prevent the air that flows into the tail-mounted nacelle14from spilling between the fans78.

As is best shown inFIGS. 1 and 12, vertical yaw vanes82extends rearwardly through the flow-through duct74of the nacelle14behind each of the electric motors76. The yaw vanes82are rotatable at a vertical pivot84within the flow-through duct74by which to provide the aircraft1with improved yaw control at low speeds. The rotatable yaw vanes82advantageously eliminate the need for a vertically upstanding tail that is common to most aircraft to provide yaw control.

By virtue of locating the turbo generators8behind the rear pressure bulkhead72(ofFIG. 12), the pressurized passenger cabin of the aircraft1is less likely to be penetrated in the event of a rotor burst. Thus, the cabin within which the passengers are seated will correspondingly be less likely to become depressurized so as to be better able to withstand a catastrophic event of the kind caused by such a rotor burst.