A rectifier and drag reduction mechanism for underwater glider

Abstract

The present invention discloses a rectifier and drag reduction mechanism for conformal carrying of an underwater glider, belonging to the technical field of conformal carrying of an underwater glider on an AUV; it includes a movable conformal frame and an SMA deformable flexible strip; the movable conformal frame is an annular structure, circumferentially installed at the hatch of the AUV of the underwater glider, and the hatch is opened and closed by expanding and converging; the SMA deformable flexible strip is circumferentially installed at the edge of the inner side of the movable conformal frame, including a U-shaped SMA sheet, a polyurethane elastic support sheet and a flexible rubber strip; the U-shaped SMA sheet is fixed on the polyurethane elastic support sheet to form an elastic motion component; multiple groups of elastic motion components are respectively inserted into the inner side of the flexible rubber strip, and the flexible rubber strip equipped with the elastic motion components is fixed to the inner side of the movable conformal frame. Through the cooperation of the SMA deformable flexible strip and the movable conformal frame, the redundant gap between the underwater glider and the AUV is closed during navigation, forming a smooth transition wall, thereby suppressing turbulence generation, reducing resistance, and improving conformal effect.

Description

Technical Field

[0001] The invention belongs to the technical field of conformal carrying of an AUV by an underwater glider, and in particular relates to a rectifying and drag reducing mechanism for conformal carrying of an underwater glider. Background Art

[0002] With the deepening of the development and utilization of marine resources, more and more underwater autonomous vehicles (AUVs) are being used in marine exploration and development. However, the energy carried by AUVs is limited, so using underwater gliders to carry AUVs to the predetermined sea area and then releasing AUVs to perform tasks can greatly improve the endurance and retention time of AUVs.

[0003] There are generally several ways to carry underwater AUVs, such as external mounting, dock mounting, and conformal mounting. Among them, the conformal mounting method has a simple structure, requires less space, and has less impact on the hydrodynamic performance of the underwater glider. Therefore, the conformal mounting method is most suitable for carrying AUVs on underwater gliders. In order to prevent the AUV from interfering with the underwater glider during the retrieval and release process, the existing conformal mounting technology has a certain redundant gap between the AUV and the underwater glider; however, during navigation, the exposed redundant gap and the rough surface between the underwater glider and the AUV will cause turbulence, increase the navigation resistance of the underwater glider, and affect the effect of conformal mounting.

[0004] Shape memory alloys (SMA) are materials composed of two or more metal elements that have shape memory effects through thermoelasticity and martensitic phase transformation and its inversion. Objects made of SMA can show completely different shapes at different temperatures.

[0005] Based on this, a rectifying and drag reduction mechanism for conformal underwater gliders is proposed. When the underwater glider is carrying the AUV, the conformal frame is closed, and the flexible strip with SMA is tightly attached to the wall of the AUV and the underwater glider, thereby closing the gap between the underwater glider and the AUV and providing a smooth transition wall between the underwater glider and the AUV, thereby improving the rectifying and drag reduction effect; when the AUV needs to be retracted, the conformal frame is opened, the flexible strip is deformed due to the deformation of the SMA, and the redundant gap is no longer closed, so that the AUV can be safely retracted. Summary of the invention

[0006] Technical issues to be solved:

[0007] In order to avoid the shortcomings of the prior art, the present invention provides a rectifier and drag reduction mechanism for a conformal underwater glider, which solves the problems of the prior art by coordinating and installing an SMA deformable flexible strip and a movable conformal frame, reduces the resistance of the AUV conformally carried by the underwater glider, and improves the conformal carrying effect.

[0008] The technical solution of the present invention is: a rectifying and drag reducing mechanism carried by an underwater glider in a conformal manner, the rectifying and drag reducing mechanism is installed on the AUV hatch of the underwater glider, and comprises a movable conformal frame and an SMA deformable flexible strip;

[0009] The movable conformal frame is an annular structure, which is installed circumferentially at the hatch of the AUV of the underwater glider, and the hatch is opened and closed by expanding and converging;

[0010] The SMA deformable flexible strip is installed at the edge of the inner side of the movable conformal frame along the circumferential direction; it includes a U-shaped SMA sheet, a polyurethane elastic support sheet and a flexible rubber strip; the U-shaped SMA sheet is fixed on the polyurethane elastic support sheet to form an elastic motion component; multiple groups of elastic motion components are respectively inserted into the inner side of the flexible rubber strip, and the flexible rubber strip equipped with the elastic motion components is fixed to the inner side of the movable conformal frame;

[0011] When the underwater glider is traveling with the AUV on board in a conformal manner, the movable conformal frame is closed, the U-shaped SMA sheet is not powered on, and the flexible rubber strip is tightly attached to the lower surface of the AUV under the elastic action of the polyurethane elastic sheet, closing the redundant gap between the underwater glider and the AUV and forming a smooth transition wall; when the AUV needs to be retracted or released, the U-shaped SMA sheet is powered on and heated up, generating tension, pulling the flexible rubber strip out of contact with the AUV, and at the same time the movable conformal frame is opened to make room for the AUV to enter and exit.

[0012] A further technical solution of the present invention is: the movable conformal frame includes a plurality of conformal frame units arranged along the circumferential direction; the conformal frame unit includes a conformal frame, a crank, a guide movable hinge and a guide rail, the inner side of the conformal frame is hinged to the inner wall of the underwater glider AUV cabin through the crank, and the outer side is hinged to the guide rail through the guide movable hinge; the guide rail is arranged on the underwater glider shell outside the AUV cabin and is opposite to the hinge position of the crank; the crank is driven to rotate, and at the same time, the conformal frame is driven to move along the guide rail direction under the guiding action of the guide movable hinge, thereby realizing the opening and closing of the movable conformal frame.

[0013] A further technical solution of the present invention is that the conformal frame is a strip plate structure, and the conformal frames of four circumferentially arranged conformal frame units are respectively installed on four sides of the hatch of the underwater glider AUV to form a rectangular entrance.

[0014] A further technical solution of the present invention is: the conformal frame unit includes two cranks and two guide movable hinges, which are symmetrically installed at the two ends of the conformal frame respectively; the hinged end of the crank is located in the vertical groove of the inner wall of the underwater glider AUV cabin, and the fixed end is fixed to the inner edge of the conformal frame; the hinged end of the guide movable hinge is located in the guide rail, and the fixed end is fixed to the outer edge of the conformal frame; the guide rail is located directly below the vertical groove of the inner wall of the underwater glider AUV cabin, and is perpendicular to the long side of the conformal frame.

[0015] A further technical solution of the present invention is: the middle of the guide movable hinge is a straight rod, and its two ends are respectively a hinged end and a fixed end; the hinged end is a cylindrical slider, the central axis of the slider is perpendicular to the straight rod of the guide movable hinge, and its two ends are matched with the clearance of the slides on both sides of the guide rail, so that it can make linear motion along the guide rail.

[0016] A further technical solution of the present invention is: a groove is provided inside the conformal frame, one side of the flexible rubber strip equipped with the elastic motion component is inserted into the groove of the conformal frame, and then fixed by a fastener.

[0017] A further technical solution of the present invention is that a hollow structure is formed between the upper and lower plate surfaces of the U-shaped SMA sheet for inserting a polyurethane elastic supporting sheet.

[0018] A further technical solution of the present invention is: a plurality of protrusions are arranged at the outer edge of the end surface of the polyurethane elastic supporting sheet, which are arranged opposite to the through holes on the U-shaped SMA sheet; after the polyurethane elastic supporting sheet is inserted into the U-shaped SMA sheet, the protrusions and the through holes are matched to achieve fixation of the two.

[0019] A further technical solution of the present invention is: a through hole is opened in the polyurethane elastic supporting sheet at the notch position of the U-shaped SMA sheet, and after the elastic motion component is installed into the flexible rubber strip, the fastener passes through the through hole of the polyurethane elastic supporting sheet to fix the elastic motion component and the flexible rubber strip to the inner side of the conformal frame.

[0020] A further technical solution of the present invention is that a plurality of the elastic motion components are evenly distributed along the length direction of the flexible rubber strip.

[0021] Beneficial Effects

[0022] The beneficial effect of the present invention is that the rectifying and drag reduction mechanism for conformal underwater gliders of the present invention provides a rectifying and drag reduction optimization scheme for conformal underwater gliders carrying AUVs. The redundant gap between the underwater glider and the AUV it carries is closed during navigation through the SMA deformable flexible strips and the movable conformal frame, and a smooth transition wall is formed to suppress turbulence generation, reduce resistance, and improve conformal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a schematic diagram comparing the effects of this rectifier and drag reduction mechanism.

[0024] Figure 2 This is a schematic diagram of the appearance of the elastic motion component.

[0025] Figure 3 Schematic diagram of the appearance of the SMA deformable flexible strip component.

[0026] Figure 4 Schematic diagram of the installation of the SMA deformable flexible strip component.

[0027] Figure 5 Schematic diagram of the lower part of the movable conformal frame component.

[0028] Figure 6 Schematic diagram of the upper part of the movable conformal frame component.

[0029] Figure 7 Schematic diagram of the rectifier and drag reduction mechanism (excluding the underwater glider).

[0030] Figure 8 Schematic diagram of AUV.

[0031] Fig. 9 Schematic diagram of an underwater glider carrying an AUV.

[0032] Fig.10 Schematic diagram of releasing AUV from underwater glider.

[0033] Explanation of the reference numerals: 1-flexible rubber strip; 2-elastic motion component; 3-polyurethane elastic supporting sheet; 4-U-shaped SMA sheet; 5-conformal frame; 6-guide rail; 7-crank; 8-underwater glider shell; 9-guide movable hinge; 10-underwater glider AUV cabin; 11-SMA deformable flexible strip; 12-threaded fastener; 13-AUV; 14-underwater glider. DETAILED DESCRIPTION

[0034] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0036] The purpose of the present invention is to provide a rectification and drag reduction optimization solution for an underwater glider conformally carrying an AUV, which can achieve a rectification effect by eliminating the gap between the underwater glider and the AUV when the underwater glider is sailing, thereby reducing the resistance during sailing.

[0037] This embodiment is a rectifier and drag reduction mechanism for an underwater glider that is conformable and installed on an AUV hatch of the underwater glider, and includes a movable conformal frame and an SMA deformable flexible strip 11;

[0038] The movable conformal frame is an annular structure, which is installed at the hatch of the underwater glider AUV along the circumference, and the hatch is opened and closed by expanding and converging. The movable conformal frame includes four conformal frame units arranged along the circumference. The conformal frame unit includes a conformal frame 5, a crank 7, a guide movable hinge 9 and a guide rail 6. The inner side of the conformal frame 5 is hinged to the inner wall of the underwater glider AUV cabin 10 through the crank 7, and the outer side is hinged to the guide rail 6 through the guide movable hinge 9. The guide rail 6 is arranged on the underwater glider shell outside the AUV cabin and is opposite to the hinge position of the crank 7. The crank 7 is driven to rotate, and the conformal frame 5 is driven to move along the guide rail 6 under the guidance of the guide movable hinge 9, so as to realize the opening and closing of the movable conformal frame 5. A groove is arranged on the inner side of the conformal frame 5, and one side of the flexible rubber strip 1 equipped with an elastic motion component is inserted into the groove of the conformal frame 5, and then fixed by a fastener.

[0039] The SMA deformable flexible strip 11 is circumferentially installed at the edge of the inner side of the movable conformal frame, and includes a U-shaped SMA sheet 4, a polyurethane elastic supporting sheet 3 and a flexible rubber strip 1; the U-shaped SMA sheet 4 is fixed on the polyurethane elastic supporting sheet 3 to form an elastic motion component; multiple groups of elastic motion components are respectively inserted into the inner side of the flexible rubber strip 1, and the flexible rubber strip 1 equipped with the elastic motion components is fixed to the inner side of the movable conformal frame.

[0040] When the underwater glider is traveling with the AUV in a conformal manner, the movable conformal frame is closed, the U-shaped SMA sheet 4 is not powered on, and the flexible rubber strip 1 is tightly attached to the lower surface of the AUV under the elastic action of the polyurethane elastic sheet 3, closing the redundant gap between the underwater glider and the AUV and forming a smooth transition wall; when the AUV needs to be retracted, the U-shaped SMA sheet 4 is powered on and heated up, generating a pulling force, pulling the flexible rubber strip 1 out of contact with the AUV, and at the same time the movable conformal frame is opened to make room for the AUV to enter and exit.

[0041] Preferably, the conformal frame is a strip plate structure, and the conformal frames of four circumferentially arranged conformal frame units are respectively installed on four sides of the hatch of the underwater glider AUV to form a rectangular entrance.

[0042] Preferably, the conformal frame unit includes two cranks and two guide movable hinges, which are symmetrically installed at the two ends of the conformal frame respectively; the hinged end of the crank is located in a vertical groove of the inner wall of the underwater glider AUV cabin, and the fixed end is fixed to the inner edge of the conformal frame; the hinged end of the guide movable hinge is located in the guide rail, and the fixed end is fixed to the outer edge of the conformal frame; the guide rail is located directly below the vertical groove of the inner wall of the underwater glider AUV cabin, and is perpendicular to the long side of the conformal frame.

[0043] Preferably, the middle of the guide movable hinge is a straight rod, and its two ends are respectively a hinged end and a fixed end; the hinged end is a cylindrical slider, the central axis of the slider is perpendicular to the straight rod of the guide movable hinge, and its two ends are matched with the clearance of the slides on both sides of the guide rail, so that it can make linear motion along the guide rail.

[0044] Preferably, the U-shaped SMA sheet has a hollow structure between the upper and lower plate surfaces for inserting a polyurethane elastic supporting sheet.

[0045] Preferably, three protrusions are arranged at the outer edge of the end surface of the polyurethane elastic supporting sheet, which are arranged opposite to the through holes on the U-shaped SMA sheet; after the polyurethane elastic supporting sheet is inserted into the U-shaped SMA sheet, the protrusions and the through holes cooperate to fix the two.

[0046] Preferably, the polyurethane elastic support sheet has a through hole at the notch position of the U-shaped SMA sheet. After the elastic motion component is installed into the flexible rubber strip, the fastener passes through the through hole of the polyurethane elastic support sheet to fix the elastic motion component and the flexible rubber strip to the inner side of the conformal frame.

[0047] Preferably, the plurality of elastic motion components are evenly distributed along the length direction of the flexible rubber strip.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] like Figure 1 As shown in the figure: compared with the existing conformal mounting which causes turbulence generation during navigation due to the existence of redundant gaps, resulting in a decrease in conformal effect, the present invention uses a conformal frame and a flexible rubber strip to close the redundant gap between the underwater glider and the AUV it carries during navigation, forming a smooth transition wall, thereby suppressing turbulence generation, thereby reducing resistance and improving the conformal effect.

[0050] like Figures 2 to 7 As shown: This embodiment provides a rectifying and drag reduction mechanism for conformal underwater gliders, including an SMA deformable flexible strip component and a movable conformal frame component, which are connected to the mounting groove of the conformal frame through a protrusion at the root of the flexible rubber strip, and are fastened in place by threaded fasteners through the mounting holes of the polyurethane elastic support sheet.

[0051] like Figures 2 to 4 As shown: the SMA deformable flexible strip component consists of a polyurethane elastic supporting sheet, a U-shaped SMA sheet, and a flexible rubber strip; there are three protrusions on the polyurethane elastic supporting sheet, which can be inserted into the three round holes of the U-shaped SMA sheet, so that the polyurethane elastic supporting sheet and the U-shaped SMA sheet are fixed together; when the two ends of the U-shaped SMA sheet are not powered on, due to the elastic effect of the polyurethane elastic supporting sheet, the flexible rubber strip is tightly attached to the surface of the AUV shell; when the two ends of the U-shaped SMA sheet are powered on, the U-shaped SMA sheet generates tension due to heat, pulling the polyurethane elastic supporting sheet to bend and deform, thereby driving the flexible rubber strip to bend and deform as a whole and detach from the AUV surface.

[0052] like Figures 5 to 7 As shown: this embodiment has a total of four sets of movable conformal frame components, front, back, left and right; each set of movable conformal frame components has a conformal frame, a pair of cranks, a pair of guide movable hinges, and a pair of guide rails; driven by the rotation of the cranks, the conformal frame can open and close along the guide rails due to the guiding action of the guide movable hinges.

[0053] like Figures 8 to 10 As shown: the underwater glider rectifying and drag reducing mechanism of this embodiment is installed on the AUV hatch of the underwater glider. When the underwater glider is sailing with the AUV, the movable conformal frame is in a closed state, the U-shaped SMA sheet is not powered on, and the flexible rubber strip is tightly attached to the surface of the AUV, so that there is a smooth transition wall between the AUV and the underwater glider, which plays a role in reducing turbulence and rectifying and reducing drag. When the AUV needs to be released, the U-shaped SMA sheet is powered on, and the flexible rubber strip is bent; the crank rotates, and the conformal frame opens outward along the guide rail under the guidance of the guide movable hinge, and the redundant gap is no longer closed, and the AUV can be safely released from the underwater glider; when the AUV is recovered, the crank rotates in the opposite direction, the conformal frame is closed, the U-shaped SMA sheet is powered off, the polyurethane elastic support sheet rebounds, and the flexible rubber strip is attached to the surface of the AUV again, and the underwater glider carries the AUV away.

[0054] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A rectifying and drag reducing mechanism for an underwater glider, characterized in that: The fairing and drag reduction mechanism is installed on the AUV hatch of the underwater glider, and includes a movable conformal frame and an SMA deformable flexible strip; The movable conformal frame is an annular structure, which is installed circumferentially at the hatch of the AUV of the underwater glider, and the hatch is opened and closed by expanding and converging; The SMA deformable flexible strip is installed at the edge of the inner side of the movable conformal frame along the circumferential direction; it includes a U-shaped SMA sheet, a polyurethane elastic support sheet and a flexible rubber strip; the U-shaped SMA sheet is fixed on the polyurethane elastic support sheet to form an elastic motion component; multiple groups of elastic motion components are respectively inserted into the inner side of the flexible rubber strip, and the flexible rubber strip equipped with the elastic motion components is fixed to the inner side of the movable conformal frame; When the underwater glider is traveling with the AUV on board in a conformal manner, the movable conformal frame is closed, the U-shaped SMA sheet is not powered on, and the flexible rubber strip is tightly attached to the lower surface of the AUV under the elastic action of the polyurethane elastic sheet, closing the redundant gap between the underwater glider and the AUV and forming a smooth transition wall; when the AUV needs to be retracted or released, the U-shaped SMA sheet is powered on and heated up, generating tension, pulling the flexible rubber strip out of contact with the AUV, and at the same time the movable conformal frame is opened to make room for the AUV to enter and exit.

2. The rectifying and drag reducing mechanism carried by the underwater glider according to claim 1 is characterized by: The movable conformal frame includes a plurality of conformal frame units arranged along the circumferential direction; the conformal frame unit includes a conformal frame, a crank, a guide movable hinge and a guide rail; the inner side of the conformal frame is hinged to the inner wall of the underwater glider AUV cabin through the crank, and the outer side is hinged to the guide rail through the guide movable hinge; the guide rail is arranged on the underwater glider shell outside the AUV cabin and is opposite to the hinge position of the crank; the crank is driven to rotate, and at the same time, the conformal frame is driven to move along the guide rail direction under the guiding action of the guide movable hinge, so as to realize the opening and closing of the movable conformal frame.

3. The rectifying and drag reducing mechanism carried by the underwater glider according to claim 2 is characterized by: The conformal frame is a strip plate structure, and the conformal frames of four circumferentially arranged conformal frame units are respectively installed on the four sides of the hatch of the underwater glider AUV to form a rectangular entrance.

4. The rectifying and drag reducing mechanism for the underwater glider according to claim 2 or 3, characterized in that: The conformal frame unit includes two cranks and two guide movable hinges, which are symmetrically installed at the two ends of the conformal frame respectively; the hinged end of the crank is located in the vertical groove of the inner wall of the underwater glider AUV cabin, and the fixed end is fixed to the inner edge of the conformal frame; the hinged end of the guide movable hinge is located in the guide rail, and the fixed end is fixed to the outer edge of the conformal frame; the guide rail is located directly below the vertical groove of the inner wall of the underwater glider AUV cabin, and is perpendicular to the long side of the conformal frame.

5. The rectifying and drag reducing mechanism for the underwater glider according to claim 4 is characterized by: The middle of the guide movable hinge is a straight rod, and its two ends are respectively a hinged end and a fixed end; the hinged end is a cylindrical slider, the central axis of the slider is perpendicular to the straight rod of the guide movable hinge, and its two ends are matched with the clearance of the slides on both sides of the guide rail, so that it can move linearly along the guide rail.

6. The rectifying and drag reducing mechanism for the underwater glider according to claim 4 is characterized by: A groove is arranged on the inner side of the conformal frame, and one side of the flexible rubber strip with the elastic motion component installed is inserted into the groove of the conformal frame and then fixed by a fastener.

7. The rectifying and drag reducing mechanism for the underwater glider according to claim 1 is characterized by: The U-shaped SMA sheet has a hollow structure between the upper and lower plate surfaces, which is used for inserting the polyurethane elastic supporting sheet.

8. The rectifying and drag reducing mechanism for the underwater glider according to claim 1 is characterized by: The polyurethane elastic support sheet is provided with a plurality of protrusions at the outer edge of the end surface, which are arranged opposite to the through holes on the U-shaped SMA sheet; after the polyurethane elastic support sheet is inserted into the U-shaped SMA sheet, the protrusions and the through holes are matched to achieve fixation of the two.

9. The rectifying and drag reducing mechanism for the underwater glider according to claim 1 is characterized by: The polyurethane elastic support sheet has a through hole at the notch position of the U-shaped SMA sheet. After the elastic motion component is installed in the flexible rubber strip, the fastener passes through the through hole of the polyurethane elastic support sheet to fix the elastic motion component and the flexible rubber strip to the inner side of the conformal frame.

10. The rectifying and drag reducing mechanism for the underwater glider according to claim 1 is characterized by: The plurality of elastic motion components are evenly distributed along the length direction of the flexible rubber strip.

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