Propulsion system for a V/STOL airplane

Claim 2

A propulsion system for a vertical and short takeoff and landing airplane, comprising: a nacelle having an upper surface and a lower surface forming an upper surface and a lower surface of an airfoil respectively; turbine driven fan means for forcing air through the nacelle; an upper flap located near the trailing edge of the nacelle upper surface and forming a part of the airfoil upper surface, the upper flap being pivotal from a horizontal flight position generally aligned with the nacelle upper surface to a vertical flight position pointing generally downward; a lower flap adjacent the trailing edge of the nacelle lower surface and forming a part of the airfoil lower surface, the lower flap being pivotal from a horizontal flight position generally aligned with the nacelle lower surface to a vertical flight position pointing generally downward; and an intermediate flap secured to the nacelle and pivotal between a horizontal flight position in which the intermediate flap is rearward of the lower flap, generally aligned with the nacelle lower surface and forming a part of the airfoil lower surface and a vertical flight position in which the leading edge of the intermediate flap is adjacent the trailing edge of the upper flap and in which the intermediate flap points generally downward, becoming the trailing edge of the airfoil upper surface; in the horizontal flight position, the space between the upper flap and the intermediate flap defining a horizontal flight main thrust nozzle; and in the vertical flight position, the space between the lower flap and intermediate flap defining a vertical flight main thrust nozzle.

Claim 3

The propulsion system according to claim 1 wherein the upper flap is positioned from the trailing edge of the nacelle upper surface a selected distance so that a portion of the fan means exhaust flows over the upper flap.

Claim 4

The propulsion system according to claim 1, wherein a slot is located between the leading edge of the upper flap and the nacelle upper surface, wherein the turbine driven fan means comprises a fan and a turbine engine in the nacelle, and further comprising a shroud extending from the rear of the turbine engine to the slot for separating turbine engine exhaust from fan exhaust upstream of the slot.

Claim 5

The propulsion system according to claim 1 wherein the upper flap has a pair of vanes secured to the upper flap in a space between the upper flap and the nacelle upper surface, one above the other, the vanes being spaced apart from each other and from the upper surface of the upper flap, defining an upper slot and an intermediate slot and wherein the turbine driven fan means comprises a fan and a turbine engine in the nacelle, and further comprising a shroud extending from the rear of the turbine engine and terminating at the upper slot for discharging the engine turbine exhaust, the intermediate slot discharging a portion of the fan exhaust.

Claim 6

The propulsion system according to claim 1 wherein in the vertical flight position, the leading edge of the intermediate flap is separated from the trailing edge of the upper flap by a selected distance for creating a slot to discharge a portion of the fan means exhaust to improve turning efficiency.

Claim 7

A propulsion system for a vertical and short takeoff and landing airplane, comprising; a nacelle having an upper surface and a lower surface forming an upper surface and a lower surface of an airfoil, respectively; the nacelle having a generally rectangular inlet and outlet; a turbofan engine, including a fan and a turbine engine, both mounted in the nacelle; an upper flap pivotally secured adjacent the trailing edge of the nacelle and forming a part of the airfoil upper surface, the upper flap having a pair of vanes secured between the upper surface of the upper flap and the trailing edge of the nacelle upper surface; the vanes being secured to the upper flap and pivotal with the upper flap, the vanes being spaced vertically apart from each other and vertically from the upper surface of the upper flap, defining an upper slot and an intermediate slot, the intermediate slot discharging a portion of the fan exhaust, the upper flap being pivotal between a horizontal flight position generally aligned with the nacelle upper surface, and a vertical flight position pointing generally downward for vectoring fan and engine exhaust downward; a shroud extending from the rear of the turbine engine to the upper slot for discharging the engine exhaust separate from the fan exhaust; a lower flap pivotally secured to the nacelle lower surface and forming a part of the airfoil lower surface, the lower flap being pivotal between a horizontal flight position generally aligned with the nacelle lower surface and a vertical flight position, pointing generally downward to vector the fan exhaust downward; and an intermediate flap pivotally secured to the nacelle and pivotal between a horizontal flight position to the rear of the lower flap and forming a part of the airfoil lower surface, and a vertical flight position below the upper flap, pointing generally downward and forming a part of the airfoil upper surface; in the vertical flight position, the upper flap and intermediate flap being positioned with a lower slot between their trailing and leading edges, respectively, for discharging a portion of the fan exhaust; in the horizontal flight position, the upper and intermediate flaps defining a horizontal flight main thrust nozzle; in the vertical flight position, the lower and intermediate flaps defining a vertical flight main thrust nozzle; normally, the sum of the areas of the upper slot, intermediate slot, and horizontal flight main thrust nozzle being substantially equal to the sum of the areas of the upper slot, intermediate slot, lower slot and vertical flight main thrust nozzle, and also equal to the sum of the areas of all the slots and the spaces between the flaps in all transition positions, and the flaps also may be actuated such that the sum of the areas of the slots and the nozzles vary according to a predetermined schedule in any flight position from horizontal to vertical.

Claim 8

A propulsion system for a vertical and short takeoff and landing airplane, comprising; a nacelle having an upper surface and a lower surface forming an upper surface and a lower surface of an airfoil, respectively; the nacelle having a generally rectangular inlet and outlet; a turbofan engine, including a fan and a turbine engine, both mounted in the nacelle; an upper flap pivotally secured adjacent the trailing edge of the nacelle and forming a part of the airfoil upper surface, the upper flap having a pair of vanes secured between the upper surface of the upper flap and the trailing edge of the nacelle upper surface; the vanes being secured to the upper flap and pivotal with the upper flap, the vanes being spaced vertically apart from each other and vertically from the upper surface of the upper flap, defining an upper slot and an intermediate slot, the intermediate slot discharging a portion of the fan exhaust, the upper flap being pivotal between a horizontal flight position generally aligned with the nacelle upper surface, and a vertical flight position pointing generally downward for vectoring fan and engine exhaust downward; a shroud extending from the rear of the turbine engine to the upper slot for discharging the engine exhaust separate from the fan exhaust; a lower flap pivotally secured to the nacelle lower surface and forming a part of the airfoil lower surface, the lower flap being pivotal between a horizontal flight position generally aligned with the nacelle lower surface and a vertical flight position, pointing generally downward to vector the fan exhaust downward; and an intermediate flap pivotally secured to the nacelle and pivotal between a horizontal flight position to the rear of the lower flap and forming a part of the airfoil lower surface, and a vertical flight position below the upper flap, pointing generally downward and forming a part of the airfoil upper surface; in the vertical flight position, the upper flap and intermediate flap being positioned with a lower slot between their trailing and leading edges, respectively, for discharging a portion of the fan exhaust; in the horizontal flight position, the upper and intermediate flaps defining a horizontal flight main thrust nozzle; in the vertical flight position, the lower and intermediate flaps defining a vertical flight main thrust nozzle; normally, the sum of the areas of the upper slot, intermediate slot, and horizontal flight main thrust nozzle being substantially equal to the sum of the areas of the upper slot, intermediate slot, lower slot and vertical flight main thrust nozzle, and also equal to the sum of the areas of all the slots and the spaces between the flaps in all transition positions, and the flaps also may be actuated such that the sum of the areas of the slots and the nozzles vary according to a predetermined schedule in any flight position from horizontal to vertical.

Claim 9

The propulsion system according to claim 6 wherein in the horizontal flight position, substantially 10 percent of the fan exhaust is discharged through the intermediate slot, the remainder being discharged through the horizontal flight main thrust nozzle.

Claim 10

The propulsion system according to claim 6 wherein in the vertical flight position, substantially 10 percent of the fan exhaust is discharged through the intermediate slot, and substantially 5 percent of the fan exhaust is discharged through the lower slot, with the remainder being discharged through the vertical flight main thrust nozzle.

Claim 11

The propulsion system according to claim 6 wherein between the horizontal and vertical flight positions, a centerline drawn through the upper flap pivots substantially from a negative angle of 23 degrees to a negative angle of 60 degrees, and wherein a centerline through the lower flap pivots substantially from an angle of negative 3 degrees to negative 63 degrees, and wherein a centerline through the intermediate flap pivots substantially from an angle of positive 8 degrees to negative 110 degrees, all with respect to the longitudinal axis of the airplane.