Patent Application
20170233060
Aircraft typically comprise a fuselage with a tail extending from the rear of the fuselage. The traditional T-tail style can include horizontal stabilizers, useful in providing a downforce for maintaining flight stability. However, the T-tail adds to the overall aircraft weight as well as increases aerodynamic drag.
The traditional T-tail can also induce flutter. Flutter is the phenomena where vibrations occurring in the aircraft match the natural frequency of the structure and can increase in amplitude without proper damping. Flutter further reduces aerodynamic efficiency of the aircraft and can induce shaking of the aircraft.
In one aspect, the present disclosure relates to an aircraft including a fuselage terminating in an empennage with a tail extending upwardly from the empennage. An engine strut extends from the empennage with an engine mounted to the engine strut and a moveable control surface provided on the engine strut.
In another aspect, the present disclosure relates to an empennage section of an aircraft including an engine strut extending from the empennage and defining at least a portion of a horizontal stabilizer with an engine mounted to the engine strut. A propeller with a diameter greater than 3 meters and a moveable control surface are provided on one of the horizontal stabilizer and the engine.
In yet another aspect, the present disclosure relates to an empennage section of an aircraft including an engine strut extending from the empennage and defining at least a portion of a horizontal stabilizer. An engine nacelle mounted to the engine strut, a stabilator rotatably mounted with the engine nacelle, and a moveable control surface are all provided on one of the horizontal stabilizer and the stabilator.
In the drawings:
The described embodiments of the present invention are directed to an engine strut with an engine mounted thereon that can be used, for example, in an aircraft. While this description is primarily directed towards use on an aircraft, it is also applicable to any vehicle or environment which utilizes an engine strut.
As illustrated in
Mounting an engine 122, with a propeller 134 having a large diameter, for example ranging from 3-5 meters (10-15 feet), at the empennage 116 requires the engine 122 to be mounted a considerable distance from the empennage 116 for proper propeller tip clearance or nacelle clearance. Mounting the engine 122 to the engine strut 124 at a distance that provides this clearance allows for engine strut 124 to be of a length that at least a portion of the engine strut 124 can define a horizontal stabilizer 120 positioned between the empennage 116 and the engine 122. Optionally, further extending from the engine 122 on the opposite side of the engine strut is an outboard wing section 136, which is mounted to an engine nacelle 138 housing the engine 122.
The engine 122 can be any aircraft engine having an intake, compressor, combustor, and turbine. In particular, engines having a large diameter propeller, blade, or fan intake such as a turbojet, turboprop, turboshaft, or turbofan engine can be mounted as described. The intake portion of the engine can be housed in the nacelle 138 or open to the elements (
Turning to
Both the engine strut 124 and the outboard wing section 136 can be provided with an elevator 130 as depicted. The elevator 130 provides further control for the pitch disturbance of the aircraft by providing varying offsetting downward forces which compensate for the gusting lift force provided by the wings 114.
A plurality of configurations exist regarding the placement and inclusion of an elevator, trim tab, or outboard wing section. The second and third embodiments are similar to the first embodiment; therefore, like parts will be identified with like numerals increasing by 100 and 200 respectively, with it being understood that the description of the like parts of the first embodiment applies to the second and third embodiments, unless otherwise noted.
In the third embodiment illustrated in
Regardless of the location of the elevator, the elevator and trim tab are incorporated to provide additional downforce for take-off rotation and during slow flight.
The above described embodiments provide a variety of benefits including, but not limited to, that the length of the engine strut allows for it to be used as a horizontal stabilizer. Use of the engine strut as a horizontal stabilizer replaces the function of a traditional T-Tail horizontal stabilizer. As the traditional horizontal portion of T-Tail is no longer necessary the weight of the aircraft can be reduced and the drag can also be reduced. Further still, flutter associated with a traditional T-Tail design can be eliminated. As the ratio of the propeller diameter to the core engine diameter increases more weight savings for the aircraft can be realized.
It is contemplated in
To the extent not already described, the different features and structures of the various embodiments can be used in combination with each other as desired. That one feature is not illustrated in all of the embodiments is not meant to be construed that it cannot be, but is done for brevity of description. Thus, the various features of the different embodiments can be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described. All combinations or permutations of features described herein are covered by this disclosure.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
