CN114802777A - High-efficiency low-resistance air inlet device for vertical take-off and landing aircraft - Google Patents

Abstract

The invention discloses a high-efficiency and low-resistance air intake device for a vertical take-off and landing aircraft, which includes a power section and an air intake device. The air device includes an air intake section, a steady flow section and an inner channel drag reduction plate, the intake section is located on the upper side of the power section, and the air flow is efficiently captured and decelerated through the intake section, and then passed through the steady flow. The air flow direction ensures that the flow direction of the air flow meets the working conditions of the ducted fan. The trapped vortex is generated on the rear side of the drag reducing plate in the inner channel to form an aerodynamic wall surface to reduce the turning angle of the air flow at the rear lip of the air intake device to avoid flow separation here. This leads to excessive overflow resistance, which ensures that the air intake device has a compact structure and can ensure the efficient air intake of the ducted fan from vertical take-off and landing to horizontal flight without any moving parts, which can effectively reduce the fuel consumption of the power system. And increase the range and load of the aircraft.

Description

A high-efficiency and low-resistance air intake device for vertical take-off and landing aircraft

technical field

The invention relates to the technical field of vertical take-off and landing power systems, in particular to a high-efficiency and low-resistance air intake device for vertical take-off and landing aircraft.

Background technique

The vertical take-off and landing technology can reduce or even completely get rid of the dependence of the aircraft on the runway, which can greatly reduce the aircraft's facilities requirements for the take-off and landing area. Therefore, compared with conventional fixed-wing aircraft, the vertical take-off and landing aircraft has stronger adaptability to the working area, and it has a great ability to adapt to the small take-off and landing area or complex terrain environment (remote mountainous areas, urban centers, earthquake-stricken areas). application space. With the introduction of new concepts of vertical take-off and landing aircraft in foreign countries, the most important technical forms currently include the following three types: 1) Compound helicopter: the top rotor is used to generate pulling force like a helicopter during vertical take-off and landing, and it is used in level flight. Horizontal engines mounted on the sides or tail of the fuselage generate thrust. Typical models such as the X2 high-speed helicopter of Sikorsky in the United States and the X3 helicopter of Eurocopter. 2) Tilt-rotor aircraft: The power direction is changed through the overall rotation of the engine. The engine generates upward pulling force almost vertically during take-off, landing and hovering, and the engine tilts almost horizontally to provide forward power during horizontal flight. Typical models such as the US V-22 Osprey tilt-rotor aircraft. 3) Jet-steered fixed-wing aircraft: The tiltable vector nozzle and ducted fan structure are used to achieve vertical take-off and landing and smooth flight functions, such as the British Harrier fighter and the American F35-B. The power systems of the first two types of vertical take-off and landing vehicles are realized by the combination of existing turbine engines (turboshaft/turboplasm) or by changing the rules of use. The third type of power system compares advanced military turbofan engines. The large expansion, which is generated by two-stage counter-rotating lift fans and vector nozzles to provide vertical lift, retains all the functions of a fighter after turning into level flight, so it has been widely valued.

Due to the need to achieve vertical take-off and landing, the take-off weight of the aircraft can only be 83% to 85% of the thrust of the engine, which greatly limits the aircraft's payload, seriously affects the aircraft's fuel capacity and range, and the fuel consumption during vertical take-off and landing. It is very high, accounting for 1/3 of the fuel capacity of the aircraft, which also greatly limits the combat radius of the aircraft. Whether it is the working power switching of compound helicopters, the engine steering of tilt-rotor aircraft, or the lift fans and vector nozzles of jet-steered fixed-wing aircraft, the above-mentioned existing power systems of various types of vertical take-off and landing aircraft realize the conversion of vertical and horizontal power output All need to greatly increase the structure and control complexity of the power system. In the future, it is required that vertical take-off and landing aircraft should achieve better conversion between vertical take-off and landing and forward flight modes with less effort while having vertical take-off and landing capabilities, and improve comprehensive flight performance such as speed, range, and effective load. The leap-forward improvement of these capabilities mainly depends on the design method of the adapted new power system and corresponding components.

SUMMARY OF THE INVENTION

The present invention provides a high-efficiency and low-resistance air intake device for a vertical take-off and landing aircraft, which overcomes the problems that the conventional vertical take-off and landing air intake device requires an additional actuating mechanism and is prone to generate excessive overflow resistance.

In order to achieve the above purpose, the present invention provides the following technical solutions: a high-efficiency and low-resistance air intake device for a vertical take-off and landing aircraft, comprising a power section and an air intake device, the air intake device is located on the upper side of the power section to achieve To capture the airflow, the intake device includes an intake section, a steady flow section and an inner channel drag reducing plate, the intake section is located on the upper side of the power section, and the rear end of the intake section is connected to the culvert provided. The inlet of the ducted fan is connected, and the steady flow section is located between the tail end of the intake section and the inlet of the ducted fan, the drag reducing plate of the inner channel is located at the inlet of the ducted fan, and the inner channel is located at the inlet of the ducted fan. The two ends of the drag reduction plate are connected to the inner wall of the inlet of the ducted fan, and the air intake in the ground state is ensured through the drag reduction plate of the inner channel.

Preferably, the intake section is a special-shaped pipeline design, the inlet of the intake section is inclined backward at an angle greater than 45 degrees to ensure integration with the shape of the power section, and the intake section starts to turn from the inlet , and complete a turn angle of not less than 60 degrees along the flow direction distance.

Preferably, the flow direction distance is the same as the fan radius of the duct.

Preferably, the cross-sectional shape of the intake section transitions from an irregular curve to a regular circle at the outlet of the intake section, and is connected to the steady flow section.

Preferably, the air intake section captures the airflow and decelerates the airflow.

Preferably, the steady flow section realizes the steering of the airflow to ensure that the flow direction of the airflow meets the working conditions of the ducted fan.

Preferably, the inner channel drag reduction plate includes an upper surface and a lower surface, the upper surface is controlled by a B-spline curve to generate an airfoil of relative thickness, and is laterally stretched into the inner channel drag reduction plate, the lower surface is The surface can be captured by extracting the outermost flow surface of the inner channel at the inlet of the ducted fan in combination with the numerical simulation results to ensure the capture of the airflow.

Preferably, the distance between the trailing edge line of the inner channel drag reducing plate and the air intake section accounts for one third of the radius of the fan.

Preferably, the drag reducing plate of the inner channel will reduce the turning angle of the airflow at the rear lip of the air intake device by generating a trapped vortex on the rear side thereof to form an aerodynamic wall surface, so as to avoid the turning angle of the air flow at the rear lip of the air intake device. The overflow resistance caused by the flow separation occurs, and the efficient air intake in the ground state is guaranteed.

Preferably, a ducted fan rectifying cone is arranged in the middle of the inlet of the ducted fan, and the ducted fan rectifying cone is used to integrate the direction of airflow movement during intake so as to generate smooth aerodynamic rectification.

Compared with the prior art, the beneficial effects of the present invention:

1. In the present invention, the structure of the entire air intake device is very compact and does not require any movable parts, which effectively reduces the structural weight of the air intake device and the transition state control law of the VTOL aircraft.

2. The design of the inner channel drag reduction plate used in the present invention can effectively take into account the air intake requirements of the ground and level flight conditions and ensure a lower overflow resistance, giving a more flexible arrangement scheme for the power system of the vertical take-off and landing aircraft, It can effectively reduce the fuel consumption of the power system and increase the range and load of the aircraft.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention.

In the attached image:

1 is a perspective view of an air intake device of the present invention;

Fig. 2 is the top view of the air intake device of the present invention;

Labels in the figure: 1. Power section; 2. Intake section; 3. Steady flow section; 4. Ducted fan inlet; 5. Inner channel drag reducing plate; 6. Ducted fan rectifier cone.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

Embodiment: As shown in FIG. 1 and FIG. 2 , a high-efficiency and low-resistance air intake device for a vertical take-off and landing aircraft includes a power section 1 and an air intake device, and the air intake device is located on the upper side of the power section 1 In order to capture the airflow, the intake device includes an intake section 2, a steady flow section 3 and an inner channel drag reducing plate 5, the intake section 2 is located on the upper side of the power section 1, and the intake section 2 The tail end is connected with the ducted fan inlet 4 provided, and the steady flow section 3 is located between the tail end of the air intake section 2 and the ducted fan inlet 4, and the ducted fan inlet 4 is in the middle position. A ducted fan rectifier cone 6 is provided, and the ducted fan rectifier cone 6 is used to integrate the direction of airflow movement during intake to generate smooth aerodynamic rectification. The intake section 2 is a special-shaped pipeline design. The inlet of section 2 is inclined backward at an angle greater than 45 degrees to ensure integration with the shape of the power section 1. The intake section 2 starts to turn from the inlet and completes a turning angle of not less than 60 degrees along the flow direction distance, so The flow direction distance is the same as the ducted fan radius, and the cross-sectional shape of the air inlet section 2 transitions from an irregular curve to a regular circle at the outlet of the air inlet section 2, and is connected with the steady flow section 3, The air intake section 2 realizes the capture and deceleration of the air flow, the steady flow section 3 realizes the steering of the air flow to ensure that the flow direction of the air flow meets the working conditions of the ducted fan, and the inner channel drag reducing plate 5 is located at the There are 4 inlets of the ducted fan, and both ends of the inner channel drag reduction plate 5 are connected to the inner wall of the ducted fan inlet 4. The inner channel drag reduction plate 5 ensures efficient air intake in the ground state. The inner channel drag reduction plate 5 includes an upper surface and a lower surface. The upper surface is controlled by a B-spline curve to generate an airfoil with a relative thickness of about 0.5, and is laterally stretched into the inner channel drag reduction plate 5. The lower surface is The surface captures the airflow by extracting the outermost flow surface of the inner channel at the inlet 4 of the ducted fan in combination with the numerical simulation results to ensure the capture of the airflow. The distance is about one-third of the radius of the fan, and the inner channel drag reducing plate 5 will reduce the turning angle of the airflow at the rear lip of the air intake device by generating a trapped vortex on its rear side to form an aerodynamic wall. , to avoid overflow resistance caused by flow separation at the rear lip of the air intake device, and to ensure efficient air intake in the ground state.

The specific working principle is that the inlet section of the air intake device is arranged on the upper side of the power section 1, and the inlet section is inclined backward to ensure a high degree of integration between the air intake device and the shape of the power section 1. In section 2 and steady flow section 3, deceleration and steering are realized to ensure the working conditions of the ducted fan. The high-efficiency air intake on the front side greatly reduces the structural size of the air intake device. On the other hand, in order to ensure that the air intake device does not generate excessive overflow resistance during level flight, the rear side of the inner channel of the air intake section 2 is arranged There is an inner channel drag reducing plate 5 to generate a trapped vortex, thereby forming an aerodynamic wall surface to reduce the turning angle of the airflow at the rear lip of the air intake device to avoid flow separation here and cause excessive overflow resistance, and the drag reduction The plate will not bring too much influence on the ground state, and can still ensure the efficient air intake of the air intake device.

Finally, it should be noted that the above descriptions are only preferred examples of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features therein. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A high-efficient low resistance air inlet unit for VTOL aircraft which characterized in that: including power section and air inlet unit, air inlet unit is located power section upside is in order to realize the seizure to the air current, air inlet unit includes air inlet section, stationary flow section and interior passageway drag reduction plate, the air inlet section is located the power section upside, the air inlet section tail end links to each other with the duct fan import that is equipped with, just the stationary flow section is located the air inlet section tail end with between the duct fan import, interior passageway drag reduction plate is located duct fan import department, just interior passageway drag reduction plate both ends with duct fan import inner wall links to each other, through interior passageway drag reduction plate guarantees the admit air of ground state.

2. The high-efficiency low-resistance air inlet device for the vertical take-off and landing aircraft as claimed in claim 1, wherein: the air inlet section is designed to be a special-shaped pipeline, an inlet of the air inlet section is inclined backwards at an angle larger than 45 degrees to ensure the shape of the air inlet section to be fused with the shape of the power section, and the air inlet section is turned from the inlet and completes a turning angle of not less than 60 degrees along the flow direction distance.

3. The high-efficiency low-resistance air inlet device for the VTOL aerial vehicle of claim 2, wherein: the flow direction distance is the same as the fan radius of the duct.

4. The high-efficiency low-resistance air inlet device for the VTOL aerial vehicle of claim 2, wherein: the cross-sectional shape of the air inlet section is transformed from an irregular curve into a regular circle at the outlet of the air inlet section, and is connected with the flow stabilizing section.

5. The high-efficiency low-resistance air inlet device for the VTOL aerial vehicle of claim 4, wherein: the air inlet section realizes the capture of the air flow and the deceleration of the air flow.

6. The high-efficiency low-resistance air inlet device for the VTOL aerial vehicle of claim 4, wherein: the steady flow section realizes the turning of the air flow, and ensures that the flow direction of the air flow meets the working conditions of the ducted fan.

7. The high-efficiency low-resistance air inlet device for the VTOL aircraft of claim 1, wherein: the inner channel drag reduction plate comprises an upper surface and a lower surface, the upper surface is controlled by a B-spline curve to generate a blade profile with relative thickness and is transversely stretched into the inner channel drag reduction plate, and the lower surface extracts the outermost side flow surface of the inner channel at the inlet of the ducted fan by combining a numerical simulation result to intercept so as to ensure the capture of air flow.

8. The high-efficiency low-resistance air inlet device for the VTOL aerial vehicle of claim 7, wherein: the distance between the rear edge line of the inner channel drag reduction plate and the air inlet section accounts for one third of the radius of the fan.

9. The high-efficiency low-resistance air inlet device for the VTOL aerial vehicle of claim 7, wherein: the inner channel resistance reducing plate reduces the turning angle of airflow at the rear lip of the air inlet device by generating standing vortex at the rear side of the inner channel resistance reducing plate to form a pneumatic wall surface, and overflow resistance caused by flow separation at the rear lip of the air inlet device is avoided.

10. The high-efficiency low-resistance air inlet device for the VTOL aircraft of claim 1, wherein: the ducted fan rectifying cone is arranged in the middle of the inlet of the ducted fan and used for integrating the air flow moving direction during air inlet so as to generate smooth pneumatic rectification.

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