TECHNICAL FIELD

[0001] The present disclosure relates generally to aerodynamic profiles, such as aerofoil profiles. In particular, the present disclosure relates to an aerofoil profile for improved lift efficiency.

BACKGROUND

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] Aerodynamic elements such as wings generate lift according to the Bernoulli’s principle by forcing disproportionate volumes of air above and below their aerofoil profiles. This generates a lift. However, with increase in angle of attack, a boundary layer formed on the surface of the aerodynamic element begins to separate, resulting in a turbulent flow of air, which may further cause non-optimal drag and lift characteristics for the aerodynamic element.

[0004] Therefore, there is a requirement in the art for a means to improve drag and lift characteristics of an aerodynamic element even during increased angles of attack.

[0005] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

[0006] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0007] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.

[0008] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0009] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims. OBJECTS OF THE INVENTION

[0010] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed below.

[0011] A general object of the present disclosure is to overcome limitations of the aerodynamic element.

[0012] An object of the present disclosure is to provide an aerodynamic element that provides higher lift force.

[0013] An object of the present disclosure is to provide an aerodynamic element that reduces drag.

SUMMARY

[0014] Various aspects of the present disclosure relate to the technical field of aeronautics. In particular, the present disclosure pertains to an aerodynamic element with enhanced lift and reduced drag capability.

[0015] According to an aspect of the present disclosure, the aerodynamic element includes an airfoil defining the shape of the aerodynamic element and includes a leading edge and a trailing edge. The aerodynamic element includes a plurality of secondary airfoils mounted on an upper surface of the airfoil and configured to provide a gap between the adjacent airfoils. The gap can be configured to enable flow of air there-through to prevent separation of air from the upper surface of the airfoil towards the trailing edge of the airfoil and to prevent accumulation of air at a leading edge of the plurality of secondary airfoils.

[0016] In an aspect, the aerodynamic element including the plurality of secondary airfoils is movable between a retracted position, in which the plurality of secondary airfoils is resting on each other, and a deployed position in which the plurality of secondary airfoils is moved away from the upper surface of the airfoil to create the gap between the adjacent secondary airfoils and the upper surface of the airfoil.

[0017] In an aspect, the plurality of secondary airfoils is extended at increase angle of attack of the aerodynamic element and the pluralities of secondary airfoils are extend from a point on the upper surface of the airfoil towards the trailing edge of the aerofoil. [0018] In an aspect, the plurality of secondary airfoils is adapted to be selectively individually deployed or retracted onto the aerodynamic element.

[0019] In an aspect, aerodynamic element includes a flap coupled to at least one of the trailing edges of the airfoil or the secondary airfoils.

BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0021] Similar components and/or features may have the same reference label in the figures. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. Suppose only the first reference label is used in the specification. In that case, the description applies to any similar components with the same first reference label, irrespective of the second reference label.

[0022] FIG. 1 illustrates a schematic representation of a conventional aerofoil profile of an aerodynamic element;

[0023] FIG. 2 illustrates a schematic representation of an aerofoil profile of an aerodynamic element, according to an embodiment of the present disclosure;

[0024] FIG. 3 illustrates an exemplary schematic representation of the aerofoil profile of the aerodynamic element, according to another embodiment of the present disclosure;

[0025] FIGs. 4A and 4B illustrate exemplary schematic representations of the aerofoil profile of the aerodynamic element, according to another embodiment of the present disclosure; and

[0026] FIG. 5A illustrates an exemplary schematic representation of the aerofoil profile of the aerodynamic element, according to another embodiment of the present disclosure.

[0027] FIG. 5B illustrates an exemplary schematic representation of the aerofoil profile of the aerodynamic element, according to another embodiment of the present disclosure. [0028] FIG. 6A and FIG. 6B illustrates an exemplary schematic representation of the aerofoil profile 200 of the aerodynamic element, according to another embodiment of the present disclosure.

[0029] FIGs. 7A and 7B illustrate an airfoil mounted with secondary airfoil and the problem associated with secondary airfoil.

[0030] FIGs. 7C to 7E illustrate exemplary cross section of the proposed aircraft wing having a secondary airfoil mounted on an airfoil, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0031] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit, and scope of the present disclosure as defined by the appended claims.

[0032] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.

[0033] If the specification states a component or feature "may", "can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.

[0034] As used in the description herein and throughout the claims that follow, the meaning of "a", "an", and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.

[0035] According to an aspect of the present disclosure, the aerodynamic element includes an airfoil defining the shape of the aerodynamic element and includes a leading edge and a trailing edge. The aerodynamic element includes a plurality of secondary airfoils mounted on an upper surface of the airfoil and configured to provide a gap between the adjacent airfoils. The gap can be configured to enable flow of air there-through to prevent separation of air from the upper surface of the airfoil towards the trailing edge of the airfoil and to prevent accumulation of air at a leading edge of the plurality of secondary airfoils.

[0036] In an embodiment, the aerodynamic element including the plurality of secondary airfoils is movable between a retracted position, in which the plurality of secondary airfoils is resting on each other, and a deployed position in which the plurality of secondary airfoils is moved away from the upper surface of the airfoil to create the gap between the adjacent secondary airfoils and the upper surface of the airfoil. In yet another embodiment the plurality of secondary airfoils is movable partially or completely inside the aerodynamic element.

[0037] In an embodiment, the mechanism to move the plurality of secondary airfoils can cause the airfoils to move pivotably, wherein movement of plurality of secondary airfoils towards the deployed position causes the corresponding blades to acquire angle of attack, and movement of the plurality of secondary airfoils towards the retracted position causes the corresponding secondary airfoils to lose angle of attack. In yet another embodiment, the movement of the secondary airfoils can be a combination of pivotal movement and sliding movement.

[0038] In an embodiment, the plurality of secondary airfoils is extended at increase angle of attack of the aerodynamic element and at least one of the pluralities of secondary airfoils are extended from a point on the upper surface of the airfoil towards the trailing edge of the aerofoil.

[0039] In an embodiment, the plurality of secondary airfoils is adapted to be selectively individually deployed or retracted onto the aerodynamic element.

[0040] In an embodiment, aerodynamic element includes a flap coupled to at least one of the trailing edges of the airfoil or the secondary airfoils.

[0041] FIG. 1 illustrates a schematic representation of a conventional aerofoil profile 100 of an aerodynamic element (not shown). The aerodynamic element may be a wing, a turbine blade, a fin, etc. In some embodiments, the aerodynamic element may be used in any application where the aerodynamic element may be required to provide a lift or a downward force. The aerodynamic element provides lift by forcing a flow of air about the aerofoil profile 100.

[0042] The aerofoil profile 100 generally includes a leading edge, and a trailing edge. An imaginary line connecting the leading edge with the trailing edge along the aerofoil profile 100 may be referred to as a camber. In some examples, the camber may be along a central plane of the aerofoil profile 100. In some other examples, the camber may be away from the center of the aerofoil profile 100, and more towards an edge of the aerofoil profile 100.

[0043] As the aerodynamic element moves through air, the air impinges against the aerodynamic element at the leading edge of the aerofoil profile 100. An angle that the air impinges against a plane of the aerofoil profile 100 may be referred to as an angle of attack. As the angle of attack increases, the aerofoil profile 100 forces more air to flow along a lower surface of the aerodynamic element, thereby creating a region of higher pressure under the aerodynamic element. Consequently, less air flows along a top surface of the aerodynamic element, thereby creating a region of lower pressure along the upper surface. The combination of the low pressure at top surface and high pressure at bottom surface creates a lift for the aerodynamic element.

[0044] In some cases, such as when the aerodynamic element is used as a fin in cars to provide a downthrust, the aerodynamic element may be installed such that it forces more air over a top surface and less air along a bottom surface, thereby providing a downward thrust to the aerodynamic element.

[0045] When the aerodynamic element moves through the air, and since air is a viscous fluid, a boundary layer 102 is created. The boundary layer 102 extends from a surface of the aerodynamic element up to a point where the air moves at a free stream velocity. In other words, the boundary layer 102 includes layers of air moving at a relative rest with respect to the surface of the aerodynamic element up to a point where the air is moving at the free stream velocity.

[0046] For the aerodynamic element to operate efficiently, i.e., for the aerodynamic element to have optimal lift characteristics with minimum drag, it is important for the boundary layer to remain attached to the surface of the aerodynamic element. Further, it is also important for the boundary layer to be smooth and turbulence free. [0047] However, with increase in the angle of attack, due to the nature of air flows, a separation of the boundary layer from the top surface of the aerodynamic element occurs. As illustrated in FIG. 1, the separation (marked by arrow 104) occurs towards the trailing edge of the aerofoil profile 100. The separation of the boundary layer 102 causes a turbulent flow across the top surface of the aerodynamic element, thereby increasing aerodynamic drag, and reducing lift. Furthermore, at a high enough angle of attack, referred to as critical angle of attack, there is complete separation of boundary layer from the top surface of the aerodynamic element. In such a state, the aerodynamic element is no longer able to generate any lift, and the aerodynamic element is said to have stalled.

[0048] In some embodiments, the present disclosure provides an aerofoil profile for an aerodynamic element such as a wing, turbine blade, fin, etc. that facilitates the aerodynamic element to keep the boundary layer attached to its top surface with increasing angle of attack, at least up until the critical angle of attack is reached.

[0049] FIG. 2 illustrates a schematic representation of an aerofoil profile 200 (also referred as airfoil) of an aerodynamic element, according to an embodiment of the present disclosure. The aerofoil profile 200 includes a secondary airfoil 202 disposed on top surface of the airfoil. The secondary airfoil 202 extends from a point on the upper surface of the aerofoil profile 200 up until the trailing edge of the aerofoil profile 200. In some embodiments, the secondary airfoil 202 may be a retractable element, and may be selectively extended as and when required. At other times, the secondary airfoil 202 may be retracted into the aerodynamic element. In some embodiments, the secondary airfoil 202 may be extended at increase angles of attack of the aerodynamic element when the boundary layer 102 begins to separate from the top surface of the aerodynamic element. The presence of the secondary airfoil 202 allows the boundary layer 102 to remain attached to the top surface of the aerodynamic element. Specifically, the boundary layer 102 remains attached to the secondary airfoil 202. As a result, the air flow along the top surface may remain smooth and turbulent free even at increased angles of attack, thereby maintaining optimum lift and drag characteristics for the aerodynamic element.

[0050] FIG. 3 illustrates an exemplary schematic representation of the aerofoil profile 200 of the aerodynamic element, according to another embodiment of the present disclosure. In some embodiments, in order to improve attachment of the boundary layer 102 with the top surface of the aerodynamic element, the airfoil 200 may include a plurality of airfoil (302-1, 302-2). At increased angles of attack, any one or more of the pluralities of secondary airfoil 302 may be extended. The plurality of secondary airfoils 302 may be arranged such that a first of the plurality of secondary airfoil (302-1) extends from the point on the upper surface of the aerofoil profile 200 up until the trailing edge of the aerofoil profile 200. Further, a second of the plurality of secondary airfoil (302-2) may extend from the point of the first of the secondary airfoil (302-1) up until the trailing edge of the aerofoil profile 200. The plurality of secondary airfoil 302 may be adapted to be selectively individually extended or retracted into the aerodynamic element.

[0051] FIGs. 4A and 4B illustrate exemplary schematic representations of the aerofoil profile 200 of the aerodynamic element, according to another embodiment of the present disclosure. In some embodiments, the airfoil 200 may include a plurality of secondary airfoils (402-1, 402-2, 402-3, 402-4) arranged in series. Any one or more of the pluralities of secondary airfoil 402 may be extended or retracted as required. Each of the plurality of secondary airfoil 402 may extend partially along a length of the top surface of the aerofoil profile 200. In some embodiments, at least one of the pluralities of secondary airfoil 402-1 may extend from a point on the upper surface of the aerofoil profile 200. The remaining of the plurality of secondary airfoil (402-2 to 402-4) may be subsequently arranged and extend towards the trailing edge of the aerofoil profile 200. The plurality of secondary airfoils 402 may be adapted to be selectively individually extended or retracted into the aerodynamic element.

[0052] FIG. 5A illustrates an exemplary schematic representation of the aerofoil profile 200 of the aerodynamic element, according to another embodiment of the present disclosure. In some embodiments, the airfoil 200 may include a plurality of secondary airfoils (502-1, 502-2, 502-3) arranged in a stacked arrangement. Any one or more of the pluralities of secondary airfoil 502 may be extended or retracted as required. Each of the plurality of secondary airfoils 502 may extend partially along a length of the top surface of the aerofoil profile 200. In an example, the plurality of secondary airfoils are movable partially or completely inside the aerodynamic element.

[0053] FIG. 5B illustrates an exemplary schematic representation of the aerofoil profile 200 of the aerodynamic element, according to another embodiment of the present disclosure. The airfoil 200 may include a secondary airfoil 502. The secondary airfoil 502 may be extended or retracted as required. The secondary airfoil 502 may be mounted on an upper surface of the airfoil 200 and configured to provide a gap between the airfoil. The gap being configured to enable flow of air there-through to prevent separation of air from the upper surface of the airfoil 200 towards the trailing edge of the airfoil 200, and to prevent accumulation of air at a leading edge of the plurality of secondary airfoils 502.

[0054] An additional benefit of providing a gap between the airfoil and secondary airfoil is the ability to angle the secondary airfoil. The angled secondary airfoil (as depicted in FIG. 5B) will provide the lift of an angle of attack, thereby resolving the aforementioned problems (problem of thin secondary airfoil and problem of thick secondary airfoil), while also providing an angle of attack which increases the lift. As depicted in Figure 5B, the secondary airfoil has a tendency to pitch nose-up and an attack angle that provides additional lift.

[0055] FIG. 6A and FIG. 6B illustrates an exemplary schematic representation of the aerofoil profile 200 of the aerodynamic element, according to another embodiment of the present disclosure.

[0056] Refereeing to 6A and 6B, the airfoil 600 may have a reduced length (50% in comparison to airfoil 200) while the thickness remains same. As the shape of the airfoil 600 is aggressive it can provide more lift and also provide more turbulence and early separation of air flow. The early separation of air due to reduced length and the increased turbulence of the airfoil 600 is captured by providing a secondary airfoil. In an example, secondary airfoil 602 may be extended at increased angles of attack. The secondary airfoil slice the air directing more air to the trailing edge of the airfoil underneath. The gap between the airfoils enables flow of air there-through to prevent separation of air from the upper surface of the airfoil towards the trailing edge of the airfoil and prevent accumulation of air at a leading edge of the plurality of secondary airfoils.

[0057] FIGs. 7A and 7B illustrate an airfoil mounted with secondary airfoil and the problem associated with secondary airfoil.

[0058] As depicted in FIG 7 A, when a thin secondary airfoil is mounted to an airfoil, the separation of air is captured, but not to a greater extent. As depicted in FIG 7B, when the secondary airfoil mounted on the airfoil is thicker than the secondary airfoil depicted in FIG 7A, the separation of air is diminished to a greater extent. The thick secondary airfoil enables to maintain a high angle of attack and enhance lift efficiency. However, mounting thick airfoil results in more drag as a consequence of a gush of air accumulating at the leading edge of the secondary airfoil.

[0059] FIGs. 7C to 7E illustrate exemplary cross section of the proposed aircraft wing having a secondary airfoil mounted on an airfoil, in accordance with an embodiment of the present disclosure.

[0060] As shown in FIG. 7C, a thin secondary airfoil 704 is mounted on an upper surface of an airfoil 702. The secondary airfoil 704 moves vertically upward, creating a gap 706 between the aircraft wing 700 and the secondary airfoil 704. By creating a gap 706 between the airfoil 702 and the secondary airfoil 704, air that gathers at the leading edge of the secondary airfoil 704 can flow there-through. Additionally, the gap 706 between the secondary airfoil 704 and the airfoil 702 allows a flow of air there-through to prevent separation of air from the upper surface of the airfoil 702 towards the trailing edge of the airfoil 702, to prevent accumulation of air at a leading edge of the secondary airfoil 704.

[0061] In an embodiment, the secondary airfoil 704 may move between a retracted position and a deployed position. For an instance, in retracted position, the secondary airfoil 704 may rest on the upper surface of the airfoil 702, and in deployed position the secondary airfoil 704 is moved away (as shown in FIG. 7C) from the upper surface of the airfoil 702 to create the gap. In an example, a means (which is obvious to the person skilled in the art) may be used to move the secondary airfoil 704 to create the gap between the airfoil 702 and the secondary airfoil 704. The gap between the airfoil 702 and the secondary airfoil 704 can be varied based on the design needs and requirements.

[0062] In an embodiment, as shown in FIG. 7D a flap 708 may be coupled to the secondary airfoil. The gap between the secondary airfoil and the airfoil allows a flow of air there-through to prevent separation of air from the upper surface of the airfoil towards the trailing edge of the airfoil. The secondary airfoil slices the air and directs it to the flap. As a result, the flap 708 has more air flowing underneath it, increasing its efficiency and boosting lift.

[0063] In an embodiment, as shown in FIG. 7E the flap 708 may be coupled to the trailing edge of the airfoil. The gap between the secondary airfoil and the wing allows a flow of air there-through to prevent separation of air from the upper surface of the airfoil towards the trailing edge of the airfoil. The secondary airfoil slices the air and directs it to the flap, so the flap 708 now has more air flowing over it, as a result of which the efficiency of the flap increases thereby enhancing the lift.

[0064] The aerofoil profile of the present disclosure thus provides improved lift characteristics for the aerodynamic element and further reduces drag. The aerodynamic element of the present disclosure may be applied in various applications such as in wings of an aircraft, a turbine blade, propellor blade planes, turbine blades, helicopter rotor blades, fuselage of aircrafts, ailerons and elevators of wings, horizontal and vertical stabilizers of aircrafts, fins of cars, etc. It is to be appreciated that while the embodiments of the present disclosure have been described with reference to aircraft wings, the concept of the present disclosure can be applied to any other device that works based on the Bernoulli's principle to generate useful forces, such as a lift force, as a result of a passing air current, and all such applications are well within the scope of the present disclosure without any limitations whatsoever.

[0065] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprise” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C . . . .and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.

[0066] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.