Contemporary aircraft engine and nacelle structures typically include a fixed geometry fan exhaust nozzle formed by the outer cowl structure and the inner fixed engine cowl. The geometry of the exhaust nozzle is often a compromise between providing a satisfactory flow path for engine performance during several phases of flight, including the cruise, take-off, and landing phases. In order to achieve better engine performance across the different flight phases, a wide variety of solutions for exhaust nozzle geometry have been investigated; however, proposed solutions to the problem have proven to be complex and costly.
In one aspect, an embodiment of the invention relates to a turbine engine having an engine core, an inner cowl radially surrounding the engine core, an outer cowl radially surrounding the inner cowl and spaced from the inner cowl to form an annular passage between the inner and outer cowls that defines a nozzle, at least one control surface provided on the inner cowl and movable between a retracted position, where the nozzle has a first cross-sectional area, and an extended position where the nozzle has a second cross-sectional area that is less than the first cross-sectional area and an actuator operably coupled to the control surface and configured to move the control surface to control the cross-sectional area of the nozzle.
In the drawings:
As illustrated more clearly in
Portions of the nacelle 20 have been cut away for clarity. The nacelle 20 surrounds the turbine engine 16 including the inner cowl 32. In this manner, the nacelle 20 forms an outer cowl 34 radially surrounding the inner cowl 32. The outer cowl 34 is spaced from the inner cowl 32 to form an annular passage 36 between the inner cowl 32 and the outer cowl 34. The annular passage 36 characterizes, forms, or otherwise defines a nozzle 38 and a generally forward-to-aft bypass airflow path. It is contemplated that the outer cowl 34 or a portion thereof may translate axially relative to the inner cowl 32 and the engine core 22.
At least one control surface 40 may be provided on the inner cowl 32 and movable between a retracted position, where the nozzle 38 has a first cross-sectional area, and an extended position, shown in phantom, where the nozzle 38 has a second cross-sectional area, which is less than the first cross-sectional area. The first cross-sectional area is sized for take-off operation and the second cross-sectional area is sized for cruise operation. It is contemplated that the first and second cross-sectional areas may be sized in any suitable manner including that the second cross-sectional area may be up to ten percent less than the first cross-sectional area.
It will be understood that the at least one control surface 40 may be any suitable control surface formed from any suitable material including an acoustically treated surface. By way of further non-limiting example, the control surface 40 may be a door for the inner cowl 32 providing access to the engine core 22. In the illustrated example, the control surface 40 includes a first end 42 that is hingedly mounted to the inner cowl 32 and a second end 44, opposite the first end 42, which moves away from the inner cowl 32 when the control surface 40 moves from the retracted position (
Further still, a seal 46 may be included and may couple the second end 44 to an aft portion of the inner cowl 32. It is contemplated that the seal 46 may be any suitable seal; including that, the seal 46 may be elastic and may be sized to stretch when the control surface 40 is moved from the retracted position (
An actuator 50 may be included and may be operably coupled to the control surface 40. The actuator 50 may move the control surface 40 between the refracted position (
Further, the control surface 40 may be movable to any number of intermediate positions, between the retracted position (
Each cowl door 48 includes a first end 42 that is hingedly mounted to the inner cowl 32 and a second end 44, opposite the first end 42, which moves away from the inner cowl 32 when the cowl door 48 moves from the retracted position to the extended position. The seal 46 may be elastic and may be sized to stretch when the cowl door 48 is moved from the closed position (
The embodiments described above provide for a variety of benefits including that a variable area fan nozzle may be achieved, which achieves significant differences in efficiency. The above-described embodiments provide for variable area fan nozzles that avoid the complexity of contemporary systems and without significant impact on basic acoustic or aerodynamic performance. Contemporary variable area fan nozzles typically include complex operating systems and/or mechanisms involving additional flaps or doors, partial in flight deployment of the translating cowl and an associated two-step or multi-step thrust reverser actuation system or an additional independent actuation system. These approaches have operational safety implications, are heavy, complex, and detract from the acoustic and aerodynamic performance of the fan nozzle.
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 may 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.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2015/015473 | 2/11/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2016/130120 | 8/18/2016 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3261164 | Tumicki | Jul 1966 | A |
3279192 | Hull, Jr. | Oct 1966 | A |
3380663 | Jumelle | Apr 1968 | A |
3598318 | Schiel | Aug 1971 | A |
3599432 | Ellis | Aug 1971 | A |
3721389 | MacKinnon et al. | Mar 1973 | A |
3756026 | Timms | Sep 1973 | A |
3785567 | Fisher | Jan 1974 | A |
3913626 | McMurtry | Oct 1975 | A |
3967443 | McMurtry | Jul 1976 | A |
20080069687 | Lace | Mar 2008 | A1 |
20090208328 | Stern | Aug 2009 | A1 |
20100043394 | Pero | Feb 2010 | A1 |
20130008147 | Todorovic et al. | Jan 2013 | A1 |
20130306755 | Dittmann et al. | Nov 2013 | A1 |
Number | Date | Country |
---|---|---|
1083738 | Sep 1967 | GB |
H09-195853 | Jul 1997 | JP |
H11-159399 | Jun 1999 | JP |
2001-050110 | Feb 2001 | JP |
2015011198 | Jan 2015 | WO |
Entry |
---|
International Search Report and Written Opinion issued in connection with corresponding PCT Application No. PCT/US2015/015473 dated Nov. 26, 2015. |
International Preliminary Report on Patentability issued in connection with corresponding PCT Application No. PCT/US2015/015473 dated Aug. 15, 2017. |
Machine Translation and Notification of Reasons for Refusal issued in connection with corresponding JP Application No. 2017-541032 dated Dec. 4, 2018. |
Number | Date | Country | |
---|---|---|---|
20180017020 A1 | Jan 2018 | US |