Refined device for variable speed and angle in three-dimensional bow slamming test

Abstract

The present invention relates to a device for fine-tuning variable speed and angle for a three-dimensional bow slamming test of water entry, comprising a test tower, a motor disposed at the top of the test tower, and a height adjustment module, a release device module, a limit device module, and an angle adjustment module disposed at the lower end of the motor from top to bottom. The height adjustment module is connected to the motor via a crane hook; the height adjustment module comprises a first hand-cranked wheel, a small truss, and a worm gear screw. The first hand-cranked wheel is fixedly mounted on the small truss, which is connected to the crane hook via steel wire ropes disposed at both ends. A worm gear screw is disposed at the lower end of the small truss. The present invention can better solve the problem of fine-tuning water entry speed and angle.

Description

Technical Field

[0001] The present invention relates to the technical field of ship and ocean engineering model testing and experimentation, and more particularly to a refined device for a three-dimensional bow water entry slamming test with variable speed and angle. Background Art

[0002] When a ship navigates waves, the intense relative motion between the hull and the waves causes water from the bow to strike the water surface at a high vertical velocity, resulting in a violent slamming phenomenon. This produces large impact loads in a short period of time, leading to localized structural damage, plate and shell buckling, cabin flooding, and even complete ship structural damage. In addition to symmetrical entry of structures, the three-dimensional bow entry process in waves often exhibits asymmetric slamming. This can be caused by the hull sailing in oblique waves, the three-dimensional bow pitch and roll motion under the waves, and the nonlinear and random nature of the incident waves. However, due to the presence of certain entry angles or transverse velocities, complex physical phenomena such as flow separation and air compression can occur in this asymmetric slamming problem. Given the strong transient nonlinearity of the three-dimensional bow entry slamming problem in waves, model experiments, as a primary research method, can provide highly accurate and realistic experimental data for theoretical analysis and numerical simulation, and reveal phenomena and mechanisms such as transient flow field evolution and air compression. Therefore, conducting three-dimensional bow slamming model tests at different entry speeds and entry angles is very important for actual ship design and structural evaluation and verification.

[0003] The traditional release device cannot guarantee that the model will be affected only by gravity when releasing it. Other interference factors will occur at the moment of release. The traditional release device cannot guarantee the accuracy of the model's entry speed into the water. There are certain difficulties in adjusting the model's entry angle into the water. There are problems with fine-tuning the entry speed and angle. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a device for finely adjusting the speed and angle of a three-dimensional bow slamming test. The device can ensure that the model falls vertically only under the action of gravity during the bow slamming test. The device can conveniently and quickly adjust the speed and angle to achieve comparison of different test conditions.

[0005] The technical solution adopted by the present invention to solve its technical problems is: constructing a refined release device with variable speed and angle for impact test, including a height adjustment module, a release device module, a limit device module and an angle adjustment module. The height adjustment module includes a first hand-cranked wheel, a small truss and a worm gear screw. The first hand-cranked wheel is fixedly set on the small truss. The small truss is connected to the crane hook through steel wire ropes set at both ends. A worm gear screw is set at the lower end of the small truss; the release device module includes an electromagnet, a first iron clamping unit and a smooth connecting rod. One side of the electromagnet is fixedly set at the bottom end of the worm gear screw. After the electromagnet is powered on, the other side absorbs the first iron clamping unit through magnetic force. The first iron clamping unit is provided with a hole adapted to the smooth connecting rod, and a scale line is set on the smooth connecting rod; the limit device module includes an H-shaped limit frame and a meter wheel. The H-shaped limit frame is fixedly set on the test truss. On the left side of the H-shaped limit frame, the meter wheel is arranged on the left side of the H-shaped limit frame, and two left and right limit cylindrical holes are symmetrically arranged in the middle of the H-shaped limit frame for the smooth connecting rod to pass through. A ball bearing is arranged on the inner side of the limit cylindrical hole, and a scale indicator is arranged on the hole on the right side. The outer diameter of the meter wheel is tangent to the smooth connecting rod on the left; the angle adjustment module includes an iron clamp, a base, a screw, a slider and a second hand-cranked wheel. The left side of the base is fixedly connected to the left end of the second iron clamp, and the right side of the base is sequentially provided with a slider and a second hand-cranked wheel, and a threaded hole is provided on the slider, which engages with the screw. The second hand-cranked wheel is arranged at the left end of the screw, and the right side of the second iron clamp is connected to the slider through a double link.

[0006] In the device for refining variable speed and angle of the three-dimensional bow water-entry slamming test of the present invention, it is characterized in that the scale lines are made of steel.

[0007] According to the above solution, grease is provided in the ball bearing to increase the lubrication of the contact surface.

[0008] According to the above solution, a resistance-increasing material is provided on the slider.

[0009] According to the above solution, the outer diameter of the smooth connecting rod is equal to the inner diameter of the reserved hole of the iron clamping unit.

[0010] According to the above solution, a gap is set between the scale indicator and the outer surface of the smooth connecting rod.

[0011] According to the above solution, the meter wheel is an encoder for recording the instantaneous release speed of the model.

[0012] The implementation of the present invention's refined device for variable speed and angle in a three-dimensional bow slamming test has the following beneficial effects:

[0013] 1. The electromagnet release method adopted by the present invention can release the specimen by simply turning off the electromagnet power switch during the impact test. During the release, the specimen will not be affected by any forces other than gravity caused by the release. The model is only affected by gravity when it falls.

[0014] 2. The combination of the smooth connecting rod and the H-shaped limiter ensures that the model remains vertical during the falling process. The greased ball bearings provided in the H-shaped limiter ensure that the smooth connecting rod does not generate excessive friction when passing through the limiter circular hole column, reducing the impact on the model's falling process.

[0015] 3. The meter wheel encoder provided on the left side of the H-shaped limit frame can record the model's falling speed in real time. The data obtained can be compared with the calculated speed and can be used for error analysis in the later test data analysis stage.

[0016] 4. The first hand-cranked wheel in the height adjustment module of the present invention can be used for fine adjustment after the model height is roughly adjusted by the crane. The slider, screw and second hand-cranked wheel in the angle adjustment module can form a reversing mechanism, which converts the linear motion of the oblique angle adjustment into the rotary motion of the hand-cranked wheel, making the angle adjustment process more convenient and accurate.

[0017] 5. The present invention can meet the various working condition settings of the model with different water entry speeds and angles. It is easy to install and adjust conveniently and accurately, avoiding the expense of making multiple test devices for different working conditions. In addition, it reduces the tedious preparation work when conducting repeated slamming tests, saving money and time costs. At the same time, it also facilitates scientific research on the model in terms of slamming, has good test performance, and meets actual use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0019] Figure 1 It is a schematic structural diagram of a refined device for variable speed and angle in a three-dimensional bow water-entry slamming test according to the present invention;

[0020] Figure 2 It is a schematic structural diagram of the height adjustment module of the device for refining variable speed and angle of a three-dimensional bow water slamming test according to the present invention;

[0021] Figure 3 It is a schematic structural diagram of a release device module of a refined device for variable speed and angle in a three-dimensional bow water-entry slamming test according to the present invention;

[0022] Figure 4 It is a schematic structural diagram of a limit device module of a device for refining variable speed and angle of a three-dimensional bow water slamming test according to the present invention;

[0023] Figure 5 It is a structural schematic diagram of the angle adjustment device module of the device for refining variable speed and angle of a three-dimensional bow water-entry slamming test according to the present invention;

[0024] Figure 6 Schematic diagram of the arrangement of the present invention in the test. DETAILED DESCRIPTION

[0025] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0026] like Figure 1-6 As shown, the device for refining the variable speed and angle of the three-dimensional bow slamming test of the present invention includes a test tower, a motor is arranged on the top of the test tower, and a height adjustment module, a release device module, a limit device module and an angle adjustment module are arranged at the lower end of the motor from top to bottom. The height adjustment module is connected to the motor through a crane hook 1;

[0027] The height adjustment module includes a first hand-cranked wheel 3, a small truss and a worm gear screw 4. The first hand-cranked wheel 3 is fixedly arranged on the small truss. The small truss is connected to the crane hook 1 through steel wire ropes 2 arranged at both ends. The worm gear screw 4 is arranged at the lower end of the small truss.

[0028] The release device module includes an electromagnet 5 and a smooth connecting rod 8. One side of the electromagnet 5 is fixedly set at the bottom end of the worm gear screw 4. After the electromagnet 5 is powered on, the other side absorbs the first iron clamping unit 9 through magnetic force. The first iron clamping unit 9 is provided with a hole adapted to the smooth connecting rod 8, and a scale line 7 is provided on the smooth connecting rod 8; the scale line 7 is made of steel.

[0029] The limit device module consists of an H-shaped limit frame and a meter wheel 11. The H-shaped limit frame is fixed to the test truss, and the meter wheel 11 is located on the left side of the H-shaped limit frame. Two symmetrical cylindrical limit holes are located in the center of the H-shaped limit frame, through which the smooth connecting rod 8 passes. Ball bearings 12 are located inside these cylindrical limit holes, and grease is provided inside the ball bearings 12 to enhance contact surface lubrication. A scale indicator 13 is placed on the right hole. The outer diameter of the meter wheel 11 is tangential to the left smooth connecting rod 8. The meter wheel 11 is an encoder used to record the instantaneous release velocity of the model.

[0030] The angle adjustment module includes an iron clamp, a base, a screw 21, a slider 23, and a second hand-cranked wheel 20. The slider 23 is provided with a resistance-enhancing material. The left side of the base is fixedly connected to the left end of the second iron clamp. The right side of the base is provided with the slider 23 and the second hand-cranked wheel 20. The slider 21 is provided with a threaded hole that engages with the screw 21. The second hand-cranked wheel 20 is located at the left end of the screw 21. The right side of the second iron clamp is connected to the slider 23 via a double connecting rod 22. The outer diameter of the smooth connecting rod 8 is equal to the inner diameter of the second iron clamp 16. A gap is provided between the scale indicator 13 and the outer surface of the smooth connecting rod 8.

[0031] In a preferred embodiment of the present invention, the device comprises a height adjustment module, a release mechanism module, a limit mechanism module, and an angle adjustment module. The height adjustment module comprises a small truss, a first hand-cranked wheel 3, and a worm gear screw; the release mechanism module comprises an electromagnet 5, a first iron clamping unit 9, and a smooth connecting rod 8. In this embodiment, the electromagnet 5 is circular; the limit mechanism module comprises an H-shaped limit frame with a built-in limit cylindrical hole, and a ball pulley is installed in the limit cylindrical hole; and the angle adjustment module comprises a base, a screw 21, a slider 23, and a second iron clamping unit 16.

[0032] In a preferred embodiment of the present invention, a crane mounted on a test tower uses a crane hook 1 to lift the steel wire ropes 2 connected to the left and right sides of the height adjustment module. The steel wire ropes 2 are fixed by a steel wire rope clamp. The crane is controlled to perform coarse height adjustment of the entire device. The first hand-cranked wheel 3 on the upper portion is rotated to control the worm gear 4 to extend and retract up and down to achieve fine height adjustment. A circular electromagnet 5 is fixed to the bottom of the worm gear. The electromagnet 5 is energized for use. When the electromagnet 5 is turned off, the first iron clamping unit 9 is released. A smooth connecting rod 8 passes through a hole in the first iron clamping unit 9 that matches it. At this time, the bolt 6 is tightened. The surface of the smooth connecting rod 8 is provided with a scale line 7. The scale line 7 in the middle of the smooth connecting rod 8 is observed for fine height adjustment. The limit device module is sleeved on the middle section of the smooth connecting rod 8. The four corners of the H-shaped limit frame are punched and rigidly fixed to the middle truss of the test tower by bolts. Two limit cylindrical holes are symmetrically arranged in the H-shaped limit frame for the smooth connecting rod 8 to pass through. The limit cylindrical holes are provided with ball bearings 12 to reduce friction. The limit cylindrical holes ensure that the device enters the water vertically during the test release process without shaking. A meter wheel 11 is fixedly arranged on the H-shaped limit device module frame. The outer diameter of the meter wheel 11 is tangent to the smooth connecting rod 8. When the smooth connecting rod 8 falls, it drives the meter wheel 11 to rotate, which is used to measure the instantaneous speed of the model falling. After the smooth connecting rod 8 passes through the hole in the second iron clamping unit 16 that is adapted to it, the bolt 19 is tightened to connect it to the angle adjustment module.

[0033] In a preferred embodiment of the present invention, the angle adjustment module comprises a second iron clamping unit 16, a base, a screw 21, a slider 23, and a second hand-cranked wheel 20. The left end of the second iron clamping unit 16 is welded to the base, and the right end is fixed to the slider 23 via a double connecting rod 22. The slider 23 has a threaded hole at its center for the screw 21 to pass through. A second hand-cranked wheel 20 is positioned at the end of the screw 21 to adjust the screw 21 and control the position of the slider 23. When the slider 23 moves away from the second hand-cranked wheel 20, the inclination angle increases. The movement of the slider 23 drives the double connecting rod 22 to rotate and change the position of the second iron clamping unit 16. The base is bolted to the "well"-shaped truss in the middle of the bow model, enabling precise variation of the height, pitch, and roll angles during free-entry slamming tests to achieve the test objectives.

[0034] In the preferred embodiment of the present invention, all components are guaranteed to have processing accuracy, otherwise it will affect the implementation effect of the present invention, and all components are painted on the outside to prevent the device from rusting and affecting the accuracy. In order to avoid the wear of the scale line 7 on the mechanism due to the increase in usage time, the scale line 7 is engraved with steel and painted after ensuring a certain depth. The ball in the limit hole in the middle of the H-shaped limit frame needs to be lubricated with bearing grease to ensure that its contact surface is well lubricated to reduce the friction with the connecting rod. A very thin layer of resistance-increasing material is attached to the upper and lower curved surfaces of the slider 23 to reduce the degree of wear between the slider 23 and the slide rail.

[0035] In a preferred embodiment of the present invention, a worm gear assembly is bolted to a small truss. Steel wire ropes 2 are installed on both sides of the small truss and hoisted onto a crane hook 1. An electromagnet 5 is welded to the bottom end of the worm gear 4. The outer diameter of the smooth connecting rod 8 is equal to the inner diameters of the first and third holes reserved for the second iron clamping unit 16. After the top of the smooth connecting rod 8 is flush with the upper portion of the second iron clamping unit 16, bolts are inserted into the specimen bolt holes and tightened, allowing the second iron clamping unit 16 and the smooth connecting rod 8 to release as a single unit. An H-shaped limiter is bolted to the test tower. The H-shaped limiter ensures a stable release of the model without shaking. A ball pulley is installed within the cylindrical limiter hole to reduce friction on the smooth connecting rod 8. A 3mm gap exists between the scale indicator 13 and the outer surface of the smooth connecting rod 8. The outer diameter of the meter wheel 11 is installed tangentially to the outer surface of the smooth connecting rod 8 and serves as an encoder to record the instantaneous release speed of the model. The central thread of the slider 23 is engaged with the screw 21, and the second hand wheel 20 controls the rotation of the screw 21 to control the movement of the slider 23. The double connecting rod 22 and the bolt jointly constrain the rotation of the iron clamping unit 16 to stably adjust the angle.

[0036] The specific use steps of the present invention are as follows:

[0037] S1. Pass the smooth connecting rod 8 through the limiting cylindrical hole with the ball in the H-shaped limiting frame. After the top end of the smooth connecting rod 8 passes through the reserved hole in the first iron clamping unit 9 and is flush, tighten the bolts.

[0038] S2. Turn the second hand-cranked wheel 20 to adjust the screw 21 so that the slider 23 moves along the track. After the sliding connecting rod drives the iron clamping unit 16 to reach the target angle, tighten the bolts to fix it. After adjusting the angle, install the lower support unit on the "well"-shaped frame in the middle of the bow. Install a gasket under the bolt and fix it to the ship model through the bolt hole.

[0039] S3. Tighten the bolts after the bottom end of the smooth connecting rod 8 is flush with the second iron clamping unit 16;

[0040] S4. Start the motor to preliminarily adjust the module height. The electromagnet 5 is energized to attract the first iron clamping unit 9 and lift the entire device.

[0041] S5. Use the first hand-cranked wheel 3 to control the extension and retraction of the worm screw and observe the scale line 7 on the smooth connecting rod 8 to finely adjust the test target height.

[0042] S6. Turn off the switch of electromagnet 5 to release the modular device.

[0043] S7. After one test condition is completed, adjust the target angle by turning the hand wheel in step S2 and repeat step S4.

[0044] After completing the above steps, the bow free entry slamming test height, longitudinal angle and heel angle can be finely adjusted.

[0045] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A refined device for a three-dimensional bow slamming test with variable speed and angle, comprising a test tower with a motor installed on top, characterized in that: The lower end of the motor is provided with a height adjustment module, a release device module, a limit device module and an angle adjustment module from top to bottom, and the height adjustment module is connected to the motor through a crane hook; The height adjustment module includes a first hand-cranked wheel, a small truss and a worm gear screw, wherein the first hand-cranked wheel is fixedly arranged on the small truss, the small truss is connected to the crane hook via steel wire ropes arranged at both ends, and a worm gear screw is arranged at the lower end of the small truss; The release device module includes an electromagnet, a first iron clamping unit, and a smooth connecting rod. One side of the electromagnet is fixedly mounted at the bottom end of the worm gear screw. When the electromagnet is powered on, the other side magnetically attracts the first iron clamping unit. The first iron clamping unit is provided with a hole adapted to fit the smooth connecting rod, and the smooth connecting rod is provided with scale lines. The limit device module includes an H-shaped limit frame and a meter wheel. The H-shaped limit frame is fixedly arranged on the test truss. The meter wheel is arranged on the left side of the H-shaped limit frame. Two left and right limit cylindrical holes are symmetrically arranged in the middle of the H-shaped limit frame for the smooth connecting rod to pass through. Ball bearings are arranged inside the limit cylindrical holes. A scale indicator is set on the hole on the right side. The outer diameter of the meter wheel is tangent to the smooth connecting rod on the left. The angle adjustment module includes an iron clamp, a base, a screw, a slider and a second hand-cranked wheel. The left side of the base is fixedly connected to the left end of the second iron clamp, and the right side of the base is sequentially provided with a slider and a second hand-cranked wheel. The slider is provided with a threaded hole, and the threaded hole is engaged with the screw. The second hand-cranked wheel is provided at the left end of the screw. The right side of the second iron clamp is connected to the slider through a double link. The specific steps are as follows: S1. Pass the smooth connecting rod through the limiting cylindrical hole with the ball in the H-shaped limiting frame. After the top of the smooth connecting rod passes through the reserved hole in the first iron clamping unit and is flush, tighten the bolts. S2. Turn the second hand-cranked wheel to adjust the screw to move the slider along the track. After the sliding connecting rod drives the iron clamping unit to the target angle, tighten the bolts to secure it. After adjusting the angle, install the lower support unit on the "well"-shaped frame in the middle of the bow. Install a washer under the bolt and secure it to the ship model through the bolt hole. S3. Tighten the bolts after the bottom end of the smooth connecting rod is flush with the second iron clamping unit; S4. Start the motor to preliminarily adjust the module height. The electromagnet is energized to tighten the first iron clamping unit and lift the entire device. S5. Use the first hand crank to control the extension and retraction of the worm screw and observe the scale lines on the smooth connecting rod to finely adjust the test target height; S6, turn off the electromagnet switch to release the modular device; S7. After one test condition is completed, adjust the target angle by turning the hand wheel in step S2 and repeat step S4.

2. The device for refining variable speed and angle of three-dimensional bow slamming test according to claim 1 is characterized in that: The scale lines are made of steel.

3. The device for refining variable speed and angle of three-dimensional bow slamming test according to claim 1 is characterized in that: Grease is provided in the ball bearing to increase the lubrication of the contact surface.

4. The device for refining variable speed and angle of three-dimensional bow slamming test according to claim 1 is characterized in that: The slider is provided with a resistance-increasing material.

5. The device for refining variable speed and angle of three-dimensional bow slamming test according to claim 1 is characterized in that: The outer diameter of the smooth connecting rod is equal to the inner diameter of the reserved hole of the iron clamping unit.

6. The device for refining variable speed and angle of three-dimensional bow slamming test according to claim 1 is characterized in that: A gap is provided between the scale indicator and the outer surface of the smooth connecting rod.

7. The device for refining variable speed and angle of three-dimensional bow slamming test according to claim 1 is characterized in that: The meter wheel is an encoder for recording the instantaneous release speed of the model.

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