AIRFOIL WITH AUGMENTED LIFT

Abstract

An airfoil having a leading-edge and a trailing edge as well as a suction side and a pressure side is provided. The suction side including an injector slot towards the leading edge. There may be at least one additional slot towards the trailing edge. The airfoil may be configured for an aircraft. A method of operating an aircraft using such airfoil is also provided.

Claims

1. An airfoil configured for an aircraft and having a leading-edge and a trailing edge as well as a suction side and a pressure side, the suction side comprising an injector slot towards the leading-edge and at least one additional slot towards the trailing edge.

2. The airfoil according to claim 1, further comprising an injector flap configured to operate on the suction side and to open, close, or regulate the opening of the injector slot.

3. The airfoil according to claim 1, further comprising at least one additional flap configured to operate to open, close, or regulate the opening of the at least one additional slot.

4. The airfoil according to claim 1, wherein the injector slot and at least one additional slot is in communication with flow generating means feeding a flow to the respective injection slot and at least one additional slot.

5. The airfoil according to claim 1, wherein the injector slot is configured with injector slot flow generating means feeding an injector flow at an injector flow speed, and wherein the at least one additional slot is configured with additional slot flow generating means feeding an additional flow at an additional flow speed different or independent of the injector flow speed.

6. The airfoil according to claim 2, wherein the injector flap is hinged by a hinge arrangement towards the trailing edge of the injector flap.

7. The airfoil according to claim 6, wherein at least one additional slot is formed between a leading-edge part and a trailing edge part and wherein the at least one additional slot is configured to operate to open, close, or regulate the opening of the at least one additional slot by changing the trailing chord line of the trailing edge part relative to the leading-edge chord line of the leading-edge part.

8. A method of operating an aircraft comprising at least one airfoil according to claim 1, the method comprising: providing an open injector slot and at least one open additional slot; setting a chord line angle between the trailing edge part chord line of the trailing edge part and the leading-edge part chord line of the leading-edge part; and generating slot flow to the respective injector slot and at least one additional slot.

9. The method of claim 8, further comprising: obtaining free air flow around the airfoil; adjusting angle of attack of the airfoil; and maintaining (1700) a substantially laminar suction side flow from the injector slot and towards the trailing edge.

10. The method of claim 8, further comprising: closing the injector slot and the at least one additional slot; and operating the aircraft in flight with the chord lines of the trailing edge part and of the leading-edge part aligned.

11. A flight computer configured to perform the acts of claim 8.

12. An aircraft configured with at least one airfoil according to claim 1 and a flight computer.

Description

BRIEF DESCRIPTION

[0094] Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

[0095] FIG. 1 illustrates a perspective view of aircraft having an airfoil as aerodynamic lifting system constructed according to the teachings of the present disclosure:

[0096] FIG. 2A illustrates a cross section and a perspective view of an embodiment of an airfoil;

[0097] FIG. 2B illustrates a perspective view of the airfoil of FIG. 2A;

[0098] FIG. 3A illustrates a cross section and a perspective view of the embodiment of FIG. 2, but in a prepared setting;

[0099] FIG. 3B illustrates a perspective view of the airfoil of FIG. 2B;

[0100] FIG. 4 illustrates a cross section and a perspective view of an embodiment of an airfoil as an alternative or with further aspects;

[0101] FIG. 5 illustrates a cross section and a perspective view of an embodiment of an airfoil as an alternative or with further aspects;

[0102] FIG. 6A illustrates acts related to methods of preparing and during take-off and landing an aircraft:

[0103] FIG. 6B illustrates a method of take-off or landing;

[0104] FIG. 7A illustrates acts related to methods of cruising and operating an aircraft;

[0105] FIG. 7B illustrates a method of operating an aircraft;

[0106] FIG. 8A illustrates flows around and airfoil whilst preparing, during take-off and landing, as well as cruising an aircraft;

[0107] FIG. 8B illustrates exemplary flows established during take-off or landing;

[0108] FIG. 8C illustrates exemplary flows established during cruising; and

[0109] FIG. 9 illustrates a close up of a leading-edge part of an airfoil.

LIST OF REFERENCES

[0110]

TABLE-US-00001 Item No. Item 10 Airfoil 12 Leading-edge 14 Trailing edge 15 Chord 16 Suction side 18 Pressure side 20 Injector slot 21 Flap hinge Arrangement 22 Injector flap 24 Injector flow 25 Injector flow speed 26 Canals 30 Additional slot 32 Additional flap 34 Additional flow 35 Additional flow speed 40 Free air flow 50 Flow generating means 52 Injector flow generating means 54 Additional flow generating means 55 Communication 60 Hinge arrangement 70 Airfoil leading-edge part 71 Airfoil leading-edge part chord 72 Airfoil trailing edge part 73 Airfoil trailing edge part chord 75 Chord line angle 76 Flap actuator arrangement 77 Rotatable element 78 Actuator arm 79 Slot 80 Internal structure 81 Internal structure 82 Air flow openings opening 100 Aircraft 200 Flight computer 1000 Method of operating an aircraft 1010 Method of preparing take-off 1020 Method of take-off or landing 1030 Method of cruising 1100 Providing 1200 Setting 1300 Generating slot flow 1500 Obtaining free air flow 1600 Adjusting 1700 Maintaining 1800 Closing 1900 Operating

DETAILED DESCRIPTION

[0111] FIG. 1 illustrates an aircraft 100 configured with at least one airfoil 10, which here could be a first airfoil 10A and a second airfoil 10B for illustrative purposes.

[0112] The airfoil 10 may be configured for the aircraft 100 as exemplified in the following figures. Generally, the airfoil has a leading-edge 12 and a trailing edge 14. The airfoil 10 has a suction side 16 and a pressure side 18.

[0113] The aircraft 100 has a flight computer 200 that is configured to perform one or more actions as will be described.

[0114] FIG. 2A shows a cross section, e.g., section 2 of an airfoil 10, and FIG. 2B shows a perspective view of the same airfoil 10.

[0115] The airfoil 10 has a leading-edge 12 and a trailing edge 14. The airfoil 10 has a suction side 16 and a pressure side 18. The suction side 16 has an injector slot 20 towards the leading-edge 12 and at least one additional slot 30 towards the trailing edge 14 from the injector slot 20.

[0116] The airfoil 10 has a chord 15 as indicated in FIG. 2A.

[0117] The airfoil 10 has a chamber that serves as a communication of a flow as will be exemplified in e.g., FIGS. 8A-C.

[0118] The injector slot 20 and at least one additional slot 30 is in a communication 55 with flow generating means 50 (not shown) feeding a flow to the respective injection slot 20 and at least one additional slot 30.

[0119] FIG. 3A shows a cross section, of an airfoil 10, and FIG. 3B shows a perspective view of the same airfoil 10.

[0120] FIGS. 3A and 3B illustrates the airfoil 10 from FIGS. 2A and 2B, but details the two-part form of the airfoil 10 formed by a leading-edge part 70 and a trailing edge part 72. The respective parts having respective leading chord 71 and trailing chord 73.

[0121] There is flow generating means 50 (not shown) feeding a flow to the communication 55 resulting in an injector flow 24 out of the injector slot 20 as a function of the operation of the injector flap 22. Likewise, the flow from the communication 55 results in additional flow 34 out of the additional slot 30 and from here towards the trailing edge.

[0122] In this embodiment, the injector flap 22 is hinged by a flap hinge arrangement 21 towards the trailing edge of the injector flap 22.

[0123] The additional slot 30 is formed between a leading-edge part 70 and a trailing edge part 72. The additional slot 30 is configured to operate to open, close, or regulate the opening of the additional slot 30. The operation is changing the trailing chord 73 line of the trailing edge part 72 relative to the leading-edge chord 73 line of the leading-edge part 70.

[0124] In this and other embodiments the additional slot 30 may be opened, closed and/or operated by one or more actuating devices which for example may be electrically operated.

[0125] FIG. 4 illustrates an embodiment of an airfoil 10 with a similar configuration as illustrated in FIGS. 2 and 3.

[0126] This embodiment has a hinge-arrangement 60 operationally controlling the leading part 70 and the trailing part 72 of the airfoil 10. Independent hereof, the embodiment shows a first communication 55A for feeding the injector slot 20 and a second communication 55B for feeding the additional slot 30.

[0127] Optionally, the injector slot 20 is configured with injector slot flow generating means 52 feeding an injector flow 24 at an injector flow speed 25 and wherein the at least one additional slot 30 is configured with additional slot flow generating means 54 feeding an additional flow 34 at an additional flow speed 35 different or independent of the injector flow speed 24.

[0128] FIG. 5 illustrates in continuation of the previous figures, this figure illustrates an embodiment of an airfoil as disclosed further configured with an arrangement or array of multiple gates, canals 26, outlets in the injector slot. The suction side 16 is further configured with stream liners in the leading-edgetrailing edge direction.

[0129] Optionally, an additional slot may be configured with similar gates, canals, or outlets.

[0130] FIGS. 6 and 7 illustrate methods or acts of operating an aircraft comprising at least one airfoil as outlined or another suitable airfoil. FIG. 8 illustrates exemplary flows as established.

[0131] FIG. 6A illustrates a method of preparing take-off 1010 of an aircraft with an airfoil.

[0132] There is an act of providing 1100 an open injector slot and at least one open additional slot.

[0133] There is an act of setting 1200 a chord line angle between the trailing edge part chord line of the trailing edge part and the leading-edge part chord line of the leading-edge part. With reference to e.g., FIG. 3, the airfoil has a leading-edge part 70 with a leading-edge part chord 72 and a trailing edge part 72 with a trailing edge part chord 73.

[0134] There is an act of generating slot flow 1300 to respective injector slot and at least one additional slot.

[0135] FIG. 6B illustrates a method of take-off or landing 1020. In an embodiment, the method 1020 may be performed after the method of preparing take-off 1010 or after cruising or in flight.

[0136] In an embodiment, the method 1020 comprises the following acts:

[0137] There is an act of obtaining free air flow 1500 around the airfoil. The free airflow may be established by a thrust or drive driving the aircraft or by auxiliary air flow means. Wind conditions will also contribute to the free air flow.

[0138] There is an act of adjusting 1600 the angle of attack (AoA) of the airfoil (10).

[0139] At the same there is an act of maintaining 1700 a suction side flow from the injector slot and towards the trailing edge substantially laminar. The act of maintaining may be by using an airfoil as disclosed and/or by adjusting parameters such as the AoA, the free air flow speed, or by altering or adjusting the openings of the slots in the airfoil, altering or adjusting the slot flows.

[0140] FIG. 7A illustrates a method of cruising 1030 the aircraft with an airfoil as disclosed.

[0141] There is an act of closing 1800 the injector slot 20 and the at least one additional slot. There is an act of operating 1900 the aircraft 100 in flight or with aligning the chord lines of the trailing edge part 72 and of the leading-edge part 70.

[0142] FIG. 7B illustrates a method of operating an aircraft 1000. In an embodiment, the method 1000 may comprise of the methods 1010, 1020, 1030 outlined in FIGS. 6A, 6B and 7A. In an embodiment, the method of operating 1000 is further exemplified in FIGS. 8A-C where FIG. 8A illustrates exemplary flows established during preparing take-off 1010 as outlined in FIG. 6A, where FIG. 8B illustrates exemplary flows established during take-off or landing 1020 as outlined in FIG. 6B, and where FIG. 8C illustrates exemplary flows established during cruising 1030 or whilst in flight.

[0143] FIG. 8A is when preparing the take-off for an aircraft comprising an airfoil as disclosed. Preparing involves opening the injector slots and an additional slot (a booster slot). The flows are established and fed to the slots as illustrated so that high velocity air flow is engaged through internal chambers described. The air is dispersed from the slots as described and follows the contour defined by the airfoil. Capillary effects contribute hereto.

[0144] FIG. 8B is once the aircraft reaches the horizontal velocity required for lift or optimum lift.

[0145] The aircraft attitude is rotated to a higher-than-normal angle of attack (AoA) relative to the free airflow. The stagnation point is through this procedure located unusually close to the trailing edge.

[0146] The laminar airflow is maintained by the active airflow as described. The high AoA will provide an unusually high lift, resulting in the aircraft to take-off at an unusual low horizontal velocity, e.g., Super-STOL.

[0147] The horizontal aircraft velocity is increased towards a normal climb or cruise velocity, and the AoA is decreased synchronously with adjusting or retraction of injector and additional (booster) slots along with reduced air jets velocity.

[0148] The same procedure is followed in reversed order during descend and landing.

[0149] FIG. 8 illustrates aspect of operating an aircraft 1000 with an airfoil 10 having a leading-edge 12, a trailing edge 14 and a suction side 16. The suction side 16 has an injector slot 20 and an additional slot 30.

[0150] FIG. 8A is when preparing 1010 the take-off for an aircraft as disclosed. Preparing involves opening the injector slot 20 and an additional slot 30 (a booster slot). The flows are established and fed to the slots as illustrated so that high velocity air flow is engaged through internal chambers described. Injector flow generating means 52 provide the injector slot flow 24 at an injector flow speed 25. Additional flow generating means 54 provide the additional flow 34 at an additional flow speed 35. The air is dispersed from the slots as described and follows the contour defined by the airfoil. Capillary effects contribute hereto.

[0151] FIG. 8B in continuation of FIG. 8A is once the aircraft reaches the horizontal velocity required for lift or optimum lift.

[0152] The aircraft attitude is rotated to a higher-than-normal angle of attack (AoA) of the chord 15 relative to the free airflow 15. The stagnation point is through this procedure located unusually close to the trailing edge 14.

[0153] The laminar airflow is maintained by the active airflow as described. The high AoA will provide an unusually high lift, resulting in the aircraft to take-off at an unusual low horizontal velocity, e.g., Super-STOL.

[0154] The horizontal aircraft velocity is increased towards a normal climb or cruise velocity, and the AoA is decreased synchronously with adjusting or retraction of injector and additional (booster) slots along with reduced air jets velocity.

[0155] The same procedure is followed in reversed order during descend and landing.

[0156] FIG. 8C illustrates the flows and settings during cruise or in flight 1030. The injector slot 20 and the additional (booster) slot 30 are fully closed and retracted, and the active airflow is suspended. The airfoil in the free airflow 40 provides the necessary lift for the aircraft and thus normal flight characteristics are ensured.

[0157] FIG. 9 is a close-up of an airfoil section closest to the leading-edge in any of the embodiments illustrated in the preceding figures.

[0158] It is seen that the hinge of the flap-hinge arrangement 21 may be a sheet hinge arranged on the inside of the airfoil whereby an air tight flap hinge arrangement may be achieved.

[0159] The injector flap 22 and thereby the injector slot 20 may be controlled i.e., activated, opened, closed, regulated by a flap actuator arrangement 76 comprising a rotatable element 77 with an actuator arm 78. The actuator arm 78 has a pin (not shown) which slides in a slot 79 when the rotatable element 77 is activated and thereby rotated.

[0160] The canals previously mentioned are not shown in the present embodiment but may be present in these embodiments as they may be in any of the embodiments illustrated in previous figures.

[0161] Internal structures 80 and 81 are provided to ensure stability of the air foil. The internal structures 80, 81 may comprise various air flow openings 82 to ensure air flow in the air foil.

[0162] Furthermore, the internal structures 80, 81 particularly the internal structures 80 arranged in the length direction of the air foil may have recesses or similar to support the injector flap 22 when the injector slot is fully open thereby preventing the injector flap 22 from opening too much unintentionally.

[0163] Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0164] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements. The mention of a unit or a module does not preclude the use of more than one unit or module.