The present invention relates to aircraft design. More particularly, the present invention relates to an air intake structure absorbing and directing airflow into engines of an aircraft for reducing drag on the aircraft.
Drag is an aerodynamic force that opposes an aircraft's motion through the air and can be generated by every part of the aircraft.
Drag is generally generated by the interaction and contact of a solid body, such as an aircraft, with a fluid, such as air. In aircraft design, drag is generally a function of aircraft configuration, altitude and speed. Drag is also known to increase exponentially with speed, therefore if the aircraft speed is doubled, the drag force will be quadrupled.
Among the drag forces acting on the aircraft, two forms of drag relate to the aircraft configuration and are known as parasite drag and interference drag. Parasite drag can be generated by the shape of the aircraft, which results from the direct contact of the aircraft with the airflow. Interference drag can be generated from the interaction of deflected airflows from the body of the aircraft for example interference between deflected air from the fuselage onto the airflow generated by the wings.
Drag generally decreases the aerodynamic efficiency of the aircraft. The decrease in efficiency can cause higher fuel burn and therefore increase greenhouse gas emissions.
Hence, in light of the aforementioned, there is a need for an aircraft which, by virtue of its design and components, would be able to provide a more aerodynamically efficient design by reducing drag forces.
One object of the present invention is to provide a solution to at least one of the above-mentioned prior art drawbacks.
The present invention relates to an air intake structure exposable to an airflow, for use on an aircraft having a fuselage, wings and engines. At least one of the engines having an air intake area and being mounted on top of the wings proximate the fuselage, for reducing drag and assisting aerodynamic control surfaces in controlling the aircraft.
In accordance with an aspect of the present invention, the air intake structure comprises:
In some implementations, the plurality of perforations includes a plurality of forward perforations formed on the forward portion, a plurality of middle perforations formed on the middle portion and a plurality of aft perforations formed on the aft portion.
In some implementations, the forward portion covers a nose cone of the aircraft.
In some implementations, the aft portion covers a vertical stabilizer defining a port surface and an opposite starboard surface and a horizontal stabilizer defining a top surface and an opposite bottom surface.
In some implementations, the middle portion covers a section of the fuselage extending between the forward portion and the aft portion.
In some implementations, an offset distance between the outer skin and the fuselage is configured to allow sufficient air intake into the engines.
In some implementations, the plurality of forward perforations gradually decreases in size along the roll axis from a tip of the nose cone to an end of the nose cone.
In some implementations, the plurality of forward perforations defines an area that is configured to account for 50 to 75 percent of the air intake area of the engines above the wings.
In some implementations, edges of the plurality of forward perforations and the plurality of aft perforations are operatively connected to a heating element for heating said plurality of forward perforations and plurality of aft perforations.
In some implementations, the plurality of aft perforations includes vertical stabilizer perforations formed on the port surface and the starboard surface of the vertical stabilizer and horizontal stabilizer perforations formed on the top surface and bottom surface of the horizontal stabilizer.
In some implementations, the plurality of aft perforations defines an area that is configured to account for 20 to 40 percent of the air intake area of the engines.
In some implementations, a leading edge of the vertical stabilizer and a leading edge of the horizontal stabilizer include micro perforations.
In some implementations, at least one edge of a windshield section of the aircraft is in fluid communication with the fuselage chamber.
In some implementations, covering the plurality of closing plates on a surface of the vertical stabilizer causes a corresponding uncovering of the plurality of closing plates on the opposite surface of the vertical stabilizer.
In some implementations, covering the plurality of closing plates on a surface of the horizontal stabilizer causes a corresponding uncovering of the plurality of closing plates on the opposite surface of the horizontal stabilizer.
In some implementations, the air intake structure further includes struts connected to the interior surface of the outer skin and to the fuselage for mounting said outer skin onto the aircraft.
In some implementations, the air intake structure further comprises a chamber segmentation wall mounted inside the chamber and dividing said chamber into a left forward chamber, a left middle chamber, a left aft chamber, a right forward chamber, a right middle chamber and a right aft chamber.
In some implementations, the air intake structure further comprises a closable gate mounted inside the chamber for fluidly isolating airflow from a divided chamber selected from the group of the left forward chamber, the left middle chamber, the left aft chamber, the right forward chamber, the right middle chamber and the right aft chamber.
In accordance with another aspect of the present invention, there is provided an aircraft wing for minimizing an airfoil boundary layer separation and de-icing a leading edge of the wing, the wing comprising:
In some implementations, the air duct is in fluid communication with a corresponding air duct of a second wing.
In some implementations, the aircraft wing further comprises an isolating system for fluidly isolating the air duct from the air exhaust of the engine.
The components, advantages and other features of the invention will become more apparent upon reading of the following non-restrictive description of some optional configurations, given for the purpose of exemplification only, with reference to the accompanying drawings.
Referring to
Still referring to
The air intake structure 10 comprises an outer skin 20. The outer skin 20 has an exterior surface 24 exposed to the airflow 12 and an opposite interior surface 26, mountable on the aircraft relative to the fuselage for creating a chamber 28 between the outer skin 20 and the fuselage. The outer skin 20 is a surface that can be mounted on the fuselage and can include a surface made from a sheet metal, plastic, glass, composites, etc. The outer skin 20 may be mounted on the fuselage using different mounting mechanisms. In a preferred embodiment, the air intake structure 10 further includes struts connected to the interior surface 26 of the outer skin 20 and to the fuselage for mounting the outer skin 20 onto the aircraft. As shown in
The outer skin 20 defines a forward portion 30, a middle portion 32 extending longitudinally along a roll axis 36 to cover the engines and adapted to restrict airflow into the engines, and an aft portion 34.
In a preferred embodiment and with reference to
With reference to
The middle portion 32 covers a section of the fuselage extending between the forward portion 30 and the aft portion 34.
Preferably, the outer skin 20 is designed to fit a specific type of aircraft and to feed the engines with sufficient air. Therefore, every aircraft type can have a corresponding outer skin 20. An offset distance between the outer skin 20 and the fuselage is configured to allow sufficient air intake into the engines.
The outer skin 20 includes a plurality of perforations 22 for receiving the airflow 12, as shown in
The plurality of perforations 22 includes a plurality of forward perforations 38 formed on the forward portion 30, a plurality of middle perforations 40 formed on the middle portion 32 and a plurality of aft perforations 42 formed on the aft portion 34.
In a preferred embodiment, the plurality of forward perforations 38 gradually decreases in size along the roll axis 36 from a tip 58 of the nose cone 44 to an end 60 of the nose cone 44. A perforation at the tip 58 of the nose cone 44 will be the largest in size since the tip 58 of the nose cone 44 usually creates large drag forces and hence the gradual decrease in size of the forward perforation 38. Instead of deflecting the airflow 12 away from the nose cone 44 and therefore increasing the drag forces, the airflow 12 is absorbed by the plurality of forward perforations 38. The plurality of forward perforations 38 can define an area that is configured to account for 50 to 75 percent of the air intake area of the engines.
The plurality of aft perforations 42 includes vertical stabilizer perforations 64 formed on the port surface 48 and the starboard surface 50 of the vertical stabilizer 46 and horizontal stabilizer perforations 66 formed on the top surface 54 and bottom surface 56 of the horizontal stabilizer 52. In addition to reducing boundary layer separation along the vertical stabilizer 46 and the horizontal stabilizer 52, the plurality of aft perforations 42 can be used to manoeuver the aircraft by creating pressure differences on the vertical stabilizer 46 and on the horizontal stabilizer 52. In fact, the aft perforations 42 can replace a rudder and/or elevators of an aircraft. The use of the aft perforations 42 as flight control surfaces is described in more details below. In some implementations, the plurality of aft perforations 42 defines an area that is configured to account for 20 to 40 percent of the air intake area of the engines.
In some implementations, as shown in
In some implementations, to help preventing ice formation onto the plurality of perforations 22, edges 62 of the plurality of forward perforations 38 and the plurality of aft perforations 42 are operatively connected to a heating element (not shown) for heating said plurality of forward perforations 38 and plurality of aft perforations 42. The heating element can be a structure that produces and transfers the heat onto the edges 62 shown in
Referring to
With reference to
The air intake structure 10 comprises a plurality of closing plates 14 operatively mounted on the interior surface 26 of the outer skin 20, for covering corresponding perforations, and movable between a closed position covering the corresponding perforations and, an open position, uncovering the corresponding perforations. The closing plates 14 are rigid structures sized and configured to slide relative to the corresponding perforations for covering and uncovering said perforations. Preferably, the plurality of closing plates 14 are mounted adjacent to the vertical stabilizer perforations 64 and to the horizontal stabilizer perforations 66.
The air intake structure 10 further comprises an actuator operatively connected to the plurality of closing plates 14 for positioning said plurality of closing plates 14 between the closed position and the open position. The actuator can comprise electric, pneumatic or hydraulic actuators.
In a neutral configuration, the plurality of closing plates 14 is positioned such that the vertical stabilizer perforations 64 and the horizontal stabilizer perforations 66 are about half covered, as shown in
To create a pressure difference on the vertical stabilizer 46 and/or on the horizontal stabilizer 52, the actuator displaces a portion of the plurality of closing plates 14 for covering the corresponding perforations, as shown in
In a preferred embodiment, in order to maximize the pressure difference between two opposite surfaces of a stabilizer, the plurality of closing plates 14 on each surface of a stabilizer is configured to move in opposite direction from the corresponding plurality of closing plates 14 on the other surface of the stabilizer.
Therefore, covering the vertical stabilizer perforations 64 on a surface of the vertical stabilizer 46 causes a corresponding uncovering of the vertical stabilizer perforations 64 on the opposite surface of the vertical stabilizer 46, and covering the horizontal stabilizer perforations 66 on a surface of the horizontal stabilizer 52 causes a corresponding uncovering of the horizontal stabilizer perforations 66 on the opposite surface of the horizontal stabilizer 52. This approach can be used in conjugation with existing control surfaces, such as a rudder and elevators. In some implementations, the rudder and elevators can be locked in place while using the vertical stabilizer perforations 64 and he horizontal stabilizer perforations 66 to manoeuver the aircraft, as described above. In case of engine failure, the rudder and elevators can be unlocked to control the aircraft.
With reference to
The closable gate is mounted inside the chamber and includes at each side of the aircraft three independently movable gates. Each movable gate is configured to fluidly isolate a corresponding chamber 130, 132 or 134. The closable gate also defines an engine chamber 136 in front of each engine. As shown in
The chamber segmentation wall 120 will be beneficial in the following scenarios:
1—Cater for single engine failure by closing the closable gates 122, 124, 126 adjacent to the failed engine to isolate the chamber 28 from the engine chamber 136 and prevent air from being sucked into the chamber 28 through the failed engine.
2—Act as a speed braking mechanism by selectively closing gates 122 and thereby creating form drag inside the forward chamber 130.
3 —In addition to the struts, the segmentation wall 120 can be used for mounting the outer skin 20 onto the aircraft.
4 —Improve handling of the aircraft by utilising air pressure around it. For examples:
The above examples are merely for illustrative purposes. The use of the segmentation wall and the control of the gates can enable optimisation for other possible scenarios.
With reference to
The wing 100 comprises a slot 104 along a wingspan of said wing 100. The slot 104 refers to a narrow opening located on the upper surface of the wing 100 and approximately along the maximum thickness of the wing 100. The maximum thickness of the wing 100 may refer to the maximum thickness of each cross-section forming the wing 100.
In one embodiment, as shown in
The wing 100 also comprises an air duct 106 mounted inside the leading edge 102 of the wing 100 and is in fluid communication with air exhaust of an engine. The air duct 106 is configured to deflect a portion of the air exhaust from the engine towards the leading edge 102 and to cause the portion of the air exhaust exit through the slot 104. The amount of air exhaust to be deflected depends on several factors, such as aircraft speed, air exhaust temperature, ambient temperature, ice formation on the wing 100, etc. Rotatable deflectors with variable positions movable into exhaust stream can be used to control the amount of air exhaust to be deflected. The duct can refer to any duct, pipe, hose, channel conduit, or the like suitable for conveying the portion of the air exhaust therethrough.
With reference to
Exhaust air exiting the slot 104 can have higher velocity and temperature than the velocity and temperature of the ambient air. Since pressure decreases with higher velocity and temperature, the exhaust air can have lower pressure with reference to the ambient air and therefore, the ambient air will exert a force on the boundary layer of the wing, proportional to the pressure difference between the ambient air and air exhaust, for minimizing the airfoil boundary layer separation.
In some embodiments, the air duct 106 is in fluid communication with a corresponding air duct of a second wing and/or the fluid communication between the air duct 106 and the air exhaust of the engine is closable.
These embodiments can cater for an engine failure and/or single engine operation of the aircraft. In these scenarios, an inlet of the air duct 106 communicating with the inoperative engine exhaust can be closed. The operative engine can continue feeding air exhaust to both air duct, located in each wing.
In the above description, the same numerical references refer to similar elements. Furthermore, for the sake of simplicity and clarity, namely so as to not unduly burden the figures with several reference numbers, not all figures contain references to all the components and features, and references to some components and features may be found in only one figure, and components and features of the present invention illustrated in other figures can be easily inferred therefrom. The embodiments, geometrical configurations, materials mentioned and/or dimensions shown in the figures are optional, and are given for exemplification purposes only.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2015/058209 | 10/24/2015 | WO | 00 |