An adaptive flow direction mimicking seal whisker flow field probe

Abstract

The application discloses a self-adaptive flow direction imitated-seal-whisker flow field detector, which is characterized in that: a guide wing structure is arranged on a cross beam, and an imitated-seal-whisker structure column body is arranged on the guide wing structure; the guide wing structure drives the imitated-seal-whisker structure column body to rotate, and the imitated-seal-whisker structure column body automatically adapts to the flow direction; and the problem that the ability of the imitated-seal-whisker structure to suppress vortex-induced vibration is invalid at a large attack angle is solved; strain gauges are arranged on the cross beam; the imitated-seal-whisker structure column body drives the cross beam structure to deform; the strain gauges convert the deformation information into electrical signals and output the electrical signals; the flow speed sensing function is realized based on the resistance of the whisker column in a uniform flow field; and the wake vortex detection function is realized based on the lift of the whisker column in a wake flow field; the problem that the imitated-seal-whisker structure column body has direction sensitivity in suppressing vortex-induced vibration characteristics is solved; the vortex-induced vibration suppression in all directions is realized; the noise interference of the underwater flow field detection is reduced; and the detection precision is improved.

Description

Technical Field

[0001] This invention belongs to the field of flow field detection technology, specifically relating to a seal whisker-inspired flow field detector. Background Technology

[0002] With the deepening development of marine science and technology and the marine economy, intelligent equipment such as unmanned underwater vehicles and underwater robots are widely used to explore the ocean. Accurate perception capabilities in complex marine environments are crucial for the safe, stable, and efficient operation of intelligent marine equipment. The most important characteristic parameters of underwater flow fields include water velocity, flow direction, and wake vortices. Existing ciliary sensors are mainly based on cylindrical structures; however, due to the Karman vortex street effect, fluid flowing around blunt structures like cylinders triggers vortex-induced vibrations within the cylinder itself, introducing noise into flow field detection.

[0003] Research has found that seal whiskers can suppress vortex-induced vibrations and can be applied to the design of novel flow field detectors. Their structural feature is a wave-shaped cylinder with an elliptical cross-section. Further research indicates that the ability of the seal whisker structure to suppress vortex-induced vibrations is related to the angle of attack, which is the angle between the direction of the water flow and the major axis of the whisker's elliptical cross-section. The whisker structure is most effective at suppressing vortex-induced vibrations when the angle of attack is 0°; as the angle of attack increases, the ability to suppress vortex-induced vibrations gradually decreases; when the angle of attack is greater than 45°, the whisker structure loses its ability to suppress vortex-induced vibrations. Therefore, the ability of the seal whisker structure to suppress vortex-induced vibrations exhibits significant directional sensitivity. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides an adaptive flow direction-inspired seal whisker-shaped flow field detector. A guide vane structure drives the rotation of the seal whisker-shaped column structure, automatically adapting to the flow direction and overcoming the problem of the seal whisker-shaped structure's inability to suppress vortex-induced vibration at high angles of attack. Strain gauges are arranged on a crossbeam. The seal whisker-shaped column structure causes deformation of the crossbeam structure, and the strain gauges convert the deformation information into electrical signals. The flow velocity sensing function is based on the drag of the whisker column in a uniform flow field, and the wake vortex detection function is based on the lift of the whisker column in the wake field. This solves the problem of the directional sensitivity of the seal whisker-shaped column structure's vortex-induced vibration suppression characteristics, achieving vortex-induced vibration suppression in all directions, reducing noise interference in underwater flow field detection, and improving detection accuracy.

[0005] The technical solution adopted by this invention to solve its technical problem includes the following steps:

[0006] An adaptive flow direction seal whisker-inspired flow field detector includes a seal whisker-inspired structural column, a cross-beam ring, guide vanes, strain gauges, ceramic bearings, and a base.

[0007] The cross-beam ring includes an upper cross-beam structure and a lower ring structure; the upper cross-beam structure includes four rectangular beams, a central support plate, and a ring base; one end of each of the four rectangular beams is connected to the central support plate, and the other end is connected to the ring base.

[0008] The bottom cross-section of the imitation seal whisker structure column is elliptical, and the bottom surface of the imitation seal whisker structure column is fixedly connected to the central support plate.

[0009] The guide wing is installed on the outside of the cross beam ring, and the center line of the guide wing in the length direction is collinear with the long axis of the elliptical section.

[0010] The strain gauge is attached to the upper surface of the rectangular beam near the side of the seal whisker-like structural column.

[0011] The lower ring structure of the cross beam ring mates with the outer ring of the ceramic bearing, and the inner ring of the ceramic bearing mates with the base.

[0012] Preferably, the seal whisker-like structural column is manufactured using 3D printing technology.

[0013] Preferably, the cross beam ring and guide wing are made of aluminum and are manufactured using metal laser printing technology and machining methods; the base is made of cast iron and is manufactured using machining methods.

[0014] Preferably, the center point of the bottom surface of the seal whisker-like structure column is located at the center of the support plate, and its major axis and minor axis are collinear with the center line of the corresponding beam on the cross beam ring.

[0015] Preferably, the inner diameter of the lower ring structure is different from that of the inner diameter of the upper cross beam structure, and there is a step between them to limit the assembly position of the ceramic bearing, so as to ensure that there is a certain distance between the ceramic bearing and the cross beam structure.

[0016] Preferably, the base is a three-section stepped shaft, divided into upper, middle and lower sections. The upper section mates with the inner ring of the ceramic bearing, and the middle section is used to restrict the assembly position of the ceramic bearing. The base has a through hole in the middle and a horizontal groove at the bottom. The through hole and the horizontal groove are used to lead out the wires of the strain gauge and connect them to the external detection circuit.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. This product is based on the vortex-induced suppression characteristics of the seal whisker columnar structure. By arranging sensitive elements on the cross beam, it realizes the flow velocity sensing function based on the resistance of the whisker column in the uniform flow field, and realizes the wake vortex detection function based on the lift of the whisker column in the wake field.

[0019] 2. The guide vane structure in this product can automatically follow the direction of water flow, drive the detector to rotate, find the optimal angle, and maximize the role of the seal whisker structure column in suppressing vortex-induced vibration. Attached Figure Description

[0020] Figure 1 This is an overall structural diagram of the flow field detector of the present invention;

[0021] Figure 2 This is an exploded view of the flow field detector structure of the present invention;

[0022] Figure 3 These are detailed structural diagrams of the components of the flow field detector of the present invention: (a) cross beam ring, (b) base;

[0023] Figure 4 This is a partial assembly cross-sectional view of the flow field detector of the present invention;

[0024] Figure 5 This is a schematic diagram of the adaptive flow direction function of the flow field detector of the present invention. (a) Angle of attack is 90°, (b) in rotation, (c) Angle of attack is 0°.

[0025] Figure 6 These are modal analysis diagrams of the flow field detector of the present invention. (a) represents the first-order mode; (b) represents the second-order mode; and (c) represents the third-order mode.

[0026] In the diagram: 1—Seal whisker-like structural column, 2—Cross-shaped beam ring, 3—Guide wing, 4—Strain gauge, 5—Ceramic bearing, 6—Base. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] The purpose of this invention is to propose a novel underwater flow field detector that can adapt to the flow direction. Based on a seal whisker-like columnar structure, it achieves omnidirectional vortex-induced vibration suppression and combines wake vortex detection and flow velocity sensing functions. The sensitive structure adopts a resistance strain gauge, which provides a simple method to solve the problem of vortex-induced vibration noise suppression under large angle of attack of the seal whisker-like flow field detector.

[0029] An adaptive flow direction seal whisker-inspired flow field detector includes: a seal whisker-inspired structural column, a cross-beam ring, a guide vane, a strain gauge, a ceramic bearing, and a base.

[0030] The seal whisker-like structural column is vertically bonded to the central support plate of the cross-beam ring, forming an integral structure with the ring. Guide vanes are installed on the outer side of the cross-beam ring, with their longitudinal centerline coinciding with the major axis of the elliptical cross-section. The sensitive structure, a strain gauge, is bonded to the deformation-prone area of ​​the beam. The lower part of the cross-beam ring mates with the outer ring of a ceramic bearing, while the inner ring mates with the base.

[0031] With a fixed base, the guide vane, upon impact by the water flow, causes the crossbeam ring to rotate and adjust its direction, ultimately aligning the water flow direction with the major axis of the elliptical cross-section of the seal whisker-like column, achieving a 0° angle of attack. Under underwater flow forces, the seal whisker-like column deforms the crossbeam structure. Strain gauges on the crossbeam convert this strain into electrical signals, which are then transmitted to a detection circuit via signal lines, enabling adaptive flow field detection.

[0032] The seal whisker-like structural column is manufactured using 3D printing technology.

[0033] The cross beam ring and guide vanes are made of aluminum and are manufactured using metal laser printing technology and machining methods. The base is made of cast iron and is manufactured using machining methods. The ceramic bearings and strain gauges are standard parts.

[0034] Example:

[0035] like Figure 1 As shown, the adaptive flow direction seal whisker-inspired flow field detector mainly consists of a seal whisker-inspired structural column, a crossbeam ring, guide vanes, strain gauges, ceramic bearings, and a base. The seal whisker-inspired structural column is tightly bonded to the central support plate of the crossbeam. The crossbeam ring and guide vanes are an integral structure. Four strain gauges are respectively bonded to the upper surfaces of the four beams of the crossbeam near the column side. The crossbeam ring is tightly assembled with the outer ring of the ceramic bearing, and the base is tightly assembled with the inner ring of the ceramic bearing.

[0036] like Figure 2 , Figure 3 and Figure 4 The diagram shows the assembly relationship between the various components of the detector. For example... Figure 3 As shown in (a), the cross-beam ring mainly consists of two parts: an upper cross-beam structure and a lower ring structure. The upper cross-beam structure includes four rectangular beams, a central support plate, and a ring base.

[0037] The base of the seal whisker-shaped structural column is tightly fixed to the central support plate. The bottom cross-section of the seal whisker-shaped structural column is elliptical, with the center point of the ellipse located at the center of the support plate. Its major and minor axes are collinear with the center lines of the corresponding beams on the cross beam assembly. The guide wing side is connected to the outer side of the cross beam ring, and the center line of the guide wing in the length direction is collinear with the major axis of the ellipse of the bottom cross-section of the seal whisker-shaped structural column.

[0038] like Figure 3 (a) and Figure 4As shown, the inner surface of the lower circular structure fits tightly with the outer ring of the ceramic bearing. The inner surface of the lower circular structure has a different diameter than the inner surface of the upper crossbeam structure, and there is a step between them to limit the assembly position of the ceramic bearing, so as to ensure that there is a certain distance between the ceramic bearing and the crossbeam structure and that it will not affect the deformation of the crossbeam.

[0039] like Figure 3 (b) and Figure 4 As shown, the base is a three-section stepped shaft, divided into upper, middle and lower sections. The upper section fits tightly with the inner ring of the ceramic bearing, the middle section is used to restrict the assembly position of the ceramic bearing, the entire base has a through hole in the middle and a horizontal groove at the bottom. The through hole and the horizontal groove are used to lead out the strain gauge wires and connect them to the external detection circuit.

[0040] like Figure 5 The diagram shows the function of the detector adapting to the flow direction, with the arrows representing the direction of water flow. Figure 5 In (a), the direction of the guide vane is perpendicular to the direction of the water flow, that is, the angle of attack is 90°. The guide vane is impacted by the water flow, which generates torque and drives the device to rotate. Figure 5 (b) During the rotation, the angle of attack α gradually decreases; Figure 5 In (c), the guide vane is parallel to the airflow and is in a relatively stable state, stopping its rotation, with an angle of attack of 0°.

[0041] like Figure 6 As shown, modal analysis was performed on the designed detector, revealing the first three natural frequencies of the detector. Figure 6 (a) is a first-order mode with a characteristic frequency of 27.4 Hz; Figure 6 (b) is a second-order mode with a characteristic frequency of 30.3 Hz; Figure 6 (c) is a third-order mode with a characteristic frequency of 121.2 Hz.

[0042] In summary, this invention provides an adaptive seal whisker-shaped flow field detector. Through a guide vane structure, the detector automatically rotates with the water flow, changing the angle of attack of the seal whisker-shaped column structure to adapt to the water flow direction. This maximizes the effect of the seal whisker-shaped column structure in suppressing vortex-induced vibration, thereby reducing noise interference. The seal whisker-shaped column structure is tightly attached to the central support plate of the crossbeam structure. When subjected to the action of water flow in the flow field, the seal whisker-shaped column structure causes the crossbeam to deform. Strain gauges attached to the crossbeam convert the strain information into an electrical signal output, thus enabling the detection of the flow field.

Claims

1. An adaptive flow direction seal whisker-inspired flow field detector, characterized in that, It includes a seal whisker-inspired column structure, a cross-beam ring, guide vanes, strain gauges, ceramic bearings, and a base; The cross-beam ring includes an upper cross-beam structure and a lower ring structure; the upper cross-beam structure includes four rectangular beams, a central support plate, and a ring base; one end of each of the four rectangular beams is connected to the central support plate, and the other end is connected to the ring base. The bottom cross-section of the imitation seal whisker structure column is elliptical, and the bottom surface of the imitation seal whisker structure column is fixedly connected to the central support plate. The guide wing is installed on the outside of the cross beam ring, and the center line of the guide wing in the length direction is collinear with the long axis of the elliptical section. The strain gauge is attached to the upper surface of the rectangular beam near the side of the seal whisker-like structural column. The lower ring structure of the cross beam ring mates with the outer ring of the ceramic bearing, and the inner ring of the ceramic bearing mates with the base.

2. The adaptive flow direction seal whisker-inspired flow field detector according to claim 1, characterized in that, The seal whisker-like structural column is manufactured using 3D printing technology.

3. The adaptive flow direction seal whisker-inspired flow field detector according to claim 1, characterized in that, The cross beam ring and guide vanes are made of aluminum and are manufactured using metal laser printing technology and machining methods; the base is made of cast iron and is manufactured using machining methods.

4. The adaptive flow direction seal whisker-inspired flow field detector according to claim 1, characterized in that, The center point of the bottom surface of the imitation seal whisker structure column is located at the center of the support plate, and its long axis and short axis are collinear with the center line of the corresponding beam on the cross beam ring.

5. The adaptive flow direction seal whisker-inspired flow field detector according to claim 1, characterized in that, The inner diameter of the lower circular structure is different from that of the inner diameter of the upper cross beam structure. There is a step between the two to limit the assembly position of the ceramic bearing, so as to ensure that there is a certain distance between the ceramic bearing and the cross beam structure.

6. The adaptive flow direction seal whisker-inspired flow field detector according to claim 1, characterized in that, The base is a three-section stepped shaft, divided into upper, middle and lower sections. The upper section mates with the inner ring of the ceramic bearing, and the middle section is used to restrict the assembly position of the ceramic bearing. The base has a through hole in the middle and a horizontal groove at the bottom. The through hole and the horizontal groove are used to lead out the strain gauge wires and connect them to the external detection circuit.

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