US 4,392,621 AGranted

Directional control of engine exhaust thrust vector in a STOL-type aircraft

OwnerHermann Vietsinventor

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Abstract

A method and apparatus for controlling the direction of the thrust vector of the engine exhaust stream in an upper surface blowing type aircraft includes ducts in the aircraft wings having rotary control valves for controlling the flow of air through the ducts from a source of high pressure to the low pressure upper surface of the wing. Introduction of the airflow at the upper surface rearwardly of the jet engine produces separation of Coanda effect attachment of the engine exhaust stream from the curved upper wing surface. Coanda effect attachment deflects the exhaust stream over the wing and toward the ground and results in a predominantly vertical thrust vector which augments lift of the aircraft. However, separation of the exhaust stream from the upper surface results in a predominantly horizontal thrust vector which augments forward acceleration of the aircraft. The fluidic action of the valves can rapidly change the thrust vector between basically horizontal and highly inclined orientations.

Claims9

Dependent claims

In a short takeoff and landing aircraft having at least one wing and a jet engine mounted above and forward of the wing so as to blow its exhaust stream over an upper surface of the wing, a method of controlling the direction of the thrust vector of the engine exhaust stream, comprising the steps of:

(a) deflecting the exhaust stream of said engine over said upper surface of the wing and toward the ground by Coanda effect attachment of said exhaust stream to said upper surface, said deflecting of the exhaust stream increasing the vertical component and decreasing the horizontal component of the thrust vector of said engine exhaust stream and thereby increasing lift of said aircraft;
and
(b) controllably detaching said exhaust stream from said upper surface by introducing a flow of air between said exhaust stream and said upper surface at selected ones of a plurality of successive locations, spaced apart along said upper surface of said wing directly behind said engine and aligned in a series between the same and a rear edge of said wing, for varying the position, starting from a region of said upper surface near said rear edge of said wing and remote from said engine and progressing forwardly along said upper surface toward said engine, at which said exhaust stream becomes detached from said upper surface, said detaching of said exhaust stream increasing the horizontal component and decreasing the vertical component of the thrust vector of said engine exhaust stream and thereby increasing forward acceleration of said aircraft.

In a short takeoff and landing aircraft having at least one wing and a jet engine mounted above and forward of the wing so as to blow its exhaust stream over the wing, apparatus for controlling the direction of the thrust vector of the engine exhaust stream, comprising:

(a) an upper surface of said wing having a rearwardly and downwardly curved configuration for causing deflection of the exhaust stream of said engine along a curved path over said upper surface and toward the ground by Coanda effect attachment of said exhaust stream to said upper surface, said attachment increasing the vertical component and decreasing the horizontal component of the thrust vector of said engine exhaust stream and thereby increasing lift of said aircraft;
and
(b) means for controllably causing detachment of said exhaust stream from said upper surface by introducing a flow of air between said exhaust stream and said upper surface at selected ones of a plurality of successive locations, spaced apart along said upper surface of said wing directly behind said engine and aligned in a series between the same and a rear edge of said wing, for varying the position, starting from a region of said upper surface near said rear edge of said wing and remote from said engine and progressing forwardly along said upper surface toward said engine, at which said exhaust stream becomes detached from said upper surface, said detachment of said exhaust stream increasing the horizontal component of the thrust vector of said engine exhaust stream and thereby increasing forward acceleration of said aircraft.

Dependencies are inferred from the claim text.