CN218463863U

CN218463863U - Double-guide-vane structure for improving separation of large attack angle of electric vertical take-off and landing aircraft

Info

Publication number: CN218463863U
Application number: CN202222250732.9U
Authority: CN
Inventors: 栾健春; 王继明; 姚远; 杨万里; 党铁红; 董明
Original assignee: Shanghai Volant Aerotech Ltd
Current assignee: Shanghai Volant Aerotech Ltd
Priority date: 2022-08-26
Filing date: 2022-08-26
Publication date: 2023-02-10
Anticipated expiration: 2032-08-26

Abstract

The utility model discloses a two water conservancy diversion piece structures for improving big angle of attack separation of electronic VTOL aircraft, including aircraft motor arm, the water conservancy diversion piece is installed to aircraft motor arm head both sides, the water conservancy diversion piece is contained angle theta with the incoming flow, the scope of contained angle theta is 3 ~ 10, the water conservancy diversion piece is rectangular form structure, the leading edge of water conservancy diversion piece is the curve structure. The double vortexes generated by the flow deflectors on the two sides in the structure can effectively control the separation of a larger airfoil surface area, increase the lift coefficient and delay the stall attack angle; the bilateral flow deflectors can better improve the airfoil flow separation caused by close coupling of the motor arm and the airfoil under a large attack angle, and reduce the aerodynamic noise and structural vibration caused by the flow separation.

Description

Double-guide-vane structure for improving separation of large attack angle of electric vertical take-off and landing aircraft

Technical Field

The utility model relates to an aviation technical field, concretely relates to two water conservancy diversion piece structures for improving electronic VTOL aircraft big angle of attack separation.

Background

The application of an Electric Vertical take-off and Landing aircraft (eVTOL) relates to various scene modes such as urban passenger transport, regional passenger transport, freight transport, personal aircraft, emergency medical service and the like. The eVTOL mainly has three configurations, namely a multi-rotor configuration, a compound wing configuration and a tilt wing configuration. The multi-rotor realizes the takeoff, landing and flat flight of the eVTOL by utilizing a plurality of propellers. The eVTOL mission profile typically involves interconversion between multi-rotor and fixed-wing, requiring the aircraft to have sufficient stall margin for the fixed-wing and transition phases. Due to the blocking of the motor arms and the propellers, the airflow energy of the upper airfoil surface of the wing is weakened, the fixed wing airfoil surface has the phenomenon of flow separation at the trailing edge generally along with the increase of the attack angle, the separation area is further enlarged along with the increase of the attack angle, and the airplane enters the stall if the separation area is not controlled. Therefore, the improvement of the low speed characteristic of the electric vertical take-off and landing aircraft needs to improve the wing surface flow separation of the wing.

The airfoil flow separation means that airflow does not adhere to an object surface in certain areas of the airfoil, and the separation causes lift force to deviate from linearity, increases resistance, and causes noise increase and structural vibration problems. Further development and enlargement of the separation can cause the aircraft to stall. Stall refers to the flight condition that corresponds to when the aircraft reaches the maximum available lift coefficient. The stall condition of an aircraft is typically defined in terms of stall angle of attack or stall speed. In a stall condition, non-commanded roll, pitch, or yaw motions of the aircraft may occur. Therefore, sufficient margin must be ensured in flight to prevent the aircraft from entering stall.

The motor arm is a support arm for mounting a propeller, a motor and the like, and is generally arranged on a lower wing surface or designed to be fused with a wing. Due to the shielding and blocking of the motor arm to the airflow, the local area of the upper airfoil surface generates flow separation under a large attack angle. The prior art for improving airfoil flow separation generally adopts a vortex generator mode to increase lift force and achieve the purpose of reducing stall speed. The principle of the existing vortex ejector scheme is to grab energy from a boundary layer, the scale of the existing vortex ejector scheme is small, the existing vortex ejector scheme has a certain improvement effect on weak airflow separation and has a certain limitation on slightly strong airflow separation.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a two water conservancy diversion piece structures that are used for improving the big angle of attack separation of electronic VTOL aircraft to solve the problem of mentioning in the background art. In order to achieve the above purpose, the utility model provides a following technical scheme: the double-guide-vane structure for improving the separation of the large attack angle of the electric vertical take-off and landing aircraft comprises an aircraft motor arm, guide vanes are mounted on two sides of the head of the aircraft motor arm, the guide vanes and incoming flow form an included angle theta, the included angle theta ranges from 3 degrees to 10 degrees, the guide vanes are of long strip-shaped structures, and the front edge of each guide vane is of a curved structure.

Preferably, the leading edge of the guide vane comprises an arc-shaped structure, a straight-line-added arc-shaped structure and a double-arc-shaped structure.

Preferably, the guide vane with the arc-shaped front edge meets the condition that the length-width ratio L/W is more than or equal to 3, and the arc-shaped radius-width ratio R/W of the front edge is more than or equal to 1.

Preferably, the aircraft motor arm comprises an inner motor arm and an outer motor arm.

The utility model discloses a technological effect and advantage: the double vortexes generated by the flow deflectors on the two sides in the structure can effectively control the separation of a larger airfoil surface area, increase the lift coefficient and delay the stall attack angle; the bilateral flow deflectors can better improve the airfoil flow separation caused by close coupling of the motor arm and the airfoil under a large attack angle, and reduce the aerodynamic noise and structural vibration caused by the flow separation.

Drawings

FIG. 1 is a top view of the mounting position of the present invention on the motor arm;

FIG. 2 is a side view of the mounting position of the present invention on the motor arm;

FIG. 3 is a partial schematic view of the mounting position of the present invention on the motor arm;

FIG. 4 is a schematic view of a flow deflector with an arc-shaped leading edge;

FIG. 5 is a schematic view of a guide vane having a straight line plus arc configuration at the leading edge;

fig. 6 is a schematic view of a guide vane with a double-arc-shaped front edge.

In the figure: 1-wing, 2-propeller, 3-deflector, 4-motor arm, 5-fuselage.

Detailed Description

In order to make the technical means, the creative features, the objectives and the functions of the present invention easily understood and appreciated, the present invention will be further described with reference to the specific drawings, and in the description of the present invention, unless otherwise specified or limited, the terms "mounted," connected "and" connected "should be understood broadly, and for example, the terms" fixed connection, "detachable connection," integral connection, mechanical connection, and electrical connection may be used; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements.

Examples

As shown in fig. 1, which is a schematic view of the installation of a dual-vane structure on an electric vertical take-off and landing composite wing aircraft, a wing 1 is installed on the top of a fuselage 5, and because a motor arm 4 and a propeller 2 are close to the wing, the separation of the wing airfoil is advanced compared with the separation of the wing in a clean state due to a close coupling layout. The flow deflectors 3 on the two sides of the motor arm are generally arranged at the positions close to the two sides of the head of the motor arm 4 and form an included angle theta with the incoming flow. The wake vortex generated by the wing at a larger attack angle enables the wing surface separation flow of the wing 1 to be attached again, and the separation is delayed. In addition, the guide vane 3 may be mounted on a required airplane horn according to requirements, and is not limited to the inner horn, the outer horn or all the horns.

The mounting angle theta of the guide vane is generally in the range of 3 degrees to 10 degrees, as shown in fig. 2 and 3, the guide vane 3 is in a strip-shaped structure, as shown in fig. 4 to 6, and the front edge of the guide vane 3 comprises an arc-shaped structure, a straight line and arc-shaped structure and a double-arc-shaped structure. But are not limited to such and may be in any combination. The installation angle theta is required to meet the premise of generating stable wake vortexes with enough strength, and if the installation angle theta is too small, the wake vortexes cannot be generated and cannot play a role if the installation angle theta is consistent with the tangential direction of local airflow; too large a stagger angle can cause the wake vortex to be too high off the airfoil and not functional. Meanwhile, the guide vane 3 must have a certain length-width ratio, otherwise, the strength of the vortex is not enough, and the purpose of delaying separation cannot be achieved. For example, the guide vane with the arc-shaped front edge meets the condition that the length-width ratio L/W is more than or equal to 3, and the arc-shaped radius-width ratio R/W of the front edge is more than or equal to 1.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and variations can be made in the embodiments or in part of the technical features of the embodiments without departing from the spirit and the scope of the invention.

Claims

1. A two water conservancy diversion piece structures for improving big angle of attack separation of electronic VTOL aircraft, including aircraft horn, its characterized in that: the aircraft motor arm comprises an aircraft motor arm, and is characterized in that flow deflectors are mounted on two sides of the head of the aircraft motor arm, an included angle theta is formed between each flow deflector and incoming flow, the included angle theta ranges from 3 degrees to 10 degrees, each flow deflector is of a long strip structure, and the front edge of each flow deflector is of a curve structure.

2. The dual vane structure for improving separation of a high angle of attack of an electrically powered vtol aircraft as claimed in claim 1, wherein: the front edge of the flow deflector comprises an arc-shaped structure, a straight line and arc-shaped structure and a double-arc-shaped structure.

3. The dual vane structure for improving separation of a high angle of attack of an electrically powered VTOL aircraft as claimed in claim 2, wherein: the flow deflector with the arc-shaped front edge meets the condition that the length-width ratio L/W is more than or equal to 3, and the arc-shaped radius-width ratio R/W of the front edge is more than or equal to 1.

4. The dual vane structure for improving separation of a high angle of attack of an electrically powered vertical takeoff and landing aircraft of claim 1, wherein: the aircraft motor arm includes an inner motor arm and an outer motor arm.