A small waterplane area catamaran towing test device and test method

Abstract

The present application provides a small waterplane area catamaran towing test device and test method. The test device includes a small waterplane area catamaran model, a towing device and a measuring assembly. The upper ends of the first and second sheet structures of the model are respectively fixedly connected to the right and left sides of the fixed frame beam and tilted at a predetermined angle. The second and first sheet structures are symmetrical about the middle longitudinal section. The power device of the towing device is used to move along a parallel water surface trajectory. The towing structure is rotatably connected to the first and second sheet structures and the connection point is the first and second towing points, which are the intersection points of the cross section where the center of gravity of the ship model is located and the two thrust axes, respectively. The line connecting the towing points is the model's longitudinal tilt rotation axis. The towing structure is vertically slidably connected to the power device. The anti-lateral heeling structure is used to limit the model's heeling rotation. The measuring assembly measures the longitudinal tilt angle, heave and sinking amount and towing force. The present application achieves the geometric similarity between the towing force action point and the actual ship's thrust action point, ensuring the longitudinal motion freedom of the model's heave and pitch.

Description

Technical Field

[0001] The present application relates to the technical field of small waterplane area catamaran model tank testing, and in particular to a small waterplane area catamaran towing test device and test method. Background Art

[0002] The small waterplane area catamaran is a high-performance ship type that has evolved from the advantages of multiple ship types in actual marine activities such as developing marine resources and defending maritime rights. The conventional small waterplane area catamaran consists of an upper hull and two upright hulls fixed under the upper hull. In addition, the oblique-strut small waterplane area catamaran has also been gradually developed and applied. This ship type has a smaller superstructure and a longer hull structure. When conducting relevant model tests, more ship type elements (such as hull spacing and hull inclination angle) need to be considered, resulting in the model test of the oblique-strut small waterplane area catamaran being more technically complex.

[0003] Different from conventional monohulls and catamarans, small waterplane area catamarans have a smaller longitudinal static righting moment due to their smaller waterplane area, which is often insufficient to balance the hydrodynamic pitch moment and other interference forces acting on the hull during high-speed navigation. The longitudinal motion posture is more obviously affected by the pitch moment. Longitudinal motion stability becomes an important difficulty in the performance design of small waterplane area catamarans, and model tests are needed to study it.

[0004] In the conventional method, when conducting tests on small waterplane area catamaran models, an external power device is needed to propel the small waterplane area catamaran model to sail in the test pool. Different propulsion positions will bring different longitudinal inclination moments to the model, thereby changing the longitudinal motion posture of the model, and even causing severe longitudinal inclination at high speeds, which will have a great impact on the test results and cannot accurately predict the longitudinal motion performance of the actual ship.

[0005] In addition, since the size of the SWATH model is much smaller than the actual ship size, a more obvious roll will occur during the model test. However, conventional tests do not consider eliminating the influence of roll on pitch, which leads to inaccurate longitudinal motion data of the model obtained through the test and makes it impossible to accurately predict the longitudinal motion performance of the actual ship. Summary of the invention

[0006] The purpose of the embodiments of the present application is to provide a small waterplane area catamaran towing test device, which can achieve the geometric similarity between the model's towing force action point and the actual ship's thrust action point in vertical height, while ensuring the longitudinal movement freedom of the model's heave and pitch, thereby improving the accuracy of the small waterplane area catamaran towing test and providing technical support for its hydrodynamic performance research.

[0007] The second purpose of the embodiment of the present application is also to provide a method for conducting a small waterplane area catamaran towing test using the above-mentioned small waterplane area catamaran towing test device.

[0008] In the first aspect, a small waterplane area catamaran towing test device is provided, comprising a small waterplane area catamaran model, a towing device and a measuring assembly. The small waterplane area catamaran model comprises a fixed frame beam, a first sheet structure and a second sheet structure. The upper end of the first sheet structure is fixedly connected to the right side of the fixed frame beam, so that the first sheet structure is tilted at a predetermined angle. The upper end of the second sheet structure is fixedly connected to the left side of the fixed frame beam, so that the second sheet structure is tilted at a predetermined angle, and the second sheet structure and the first sheet structure are arranged symmetrically with respect to the longitudinal section of the middle position of the fixed frame beam. The towing device comprises a power device, a towing structure and an anti-lateral shift and heel structure. The power device is mounted above the test pool and is used to move at a predetermined speed along a predetermined trajectory parallel to the water surface. The towing structure is rotatably connected to the first sheet structure and the second sheet structure respectively. The connection point between the towing structure and the first sheet structure is the first towing point, and the connection point between the towing structure and the second sheet structure is the second towing point. The first towing point and the second towing point are the intersection points of the cross section where the center of gravity of the small waterplane area catamaran model is located and the two thrust axes respectively; the line connecting the first towing point and the second towing point is the axis of the longitudinal rotation of the small waterplane area catamaran model; the towing structure is slidably connected to the power device, and the sliding direction is always in the vertical direction. The anti-lateral heeling structure is used to make the longitudinal axis of the small waterplane area catamaran model always consistent with the forward direction of the power device, and to limit the heeling rotation of the small waterplane area catamaran model. The measuring component is used to measure the longitudinal heel angle and heave of the small waterplane area catamaran model and the towing force of the towing device.

[0009] In an implementable scheme, the first sheet structure includes a first support plate and a first submerged body fixedly connected to the lower end of the first support plate, and the upper end of the first sheet structure is fixedly connected to the right side of the fixed frame beam, so that the first support plate is tilted at a predetermined angle; the second sheet structure includes a second support plate and a second submerged body fixedly connected to the lower end of the second support plate, and the upper end of the second sheet structure is fixedly connected to the left side of the fixed frame beam, so that the second support plate is tilted at a predetermined angle, and the second sheet structure and the first sheet structure are symmetrically arranged with respect to the longitudinal section of the middle position of the fixed frame beam; the towing structure is rotatably connected to the first submerged body and the second submerged body, the connection between the towing structure and the first submerged body is the first towing point, and the connection between the towing structure and the second submerged body is the second towing point, the intersection of the axis of the first submerged body and the cross-section where the center of gravity of the small waterplane area catamaran model is located is the first towing point, and the intersection of the axis of the second submerged body and the cross-section where the center of gravity of the small waterplane area catamaran model is located is the second towing point.

[0010] In an implementable solution, a plurality of installation positions are provided on the fixed frame beam and are distributed laterally along the body thereof, and the installation positions of the first sheet structure and the second sheet structure on the fixed frame beam are adjusted to adjust the distance between the first sheet structure and the second sheet structure.

[0011] In an implementable scheme, a first cavity is set in the first support plate, and the interior of the first submerged body is a cavity, the first cavity extends from the upper end of the first support plate to the lower end and is connected to the cavity inside the first submerged body; a second cavity is set in the second support plate, and the interior of the second submerged body is a cavity, the second cavity extends from the upper end of the second support plate to the lower end and is connected to the cavity inside the second submerged body; the towing structure includes a first towing rod, a second towing rod, a fixed plate and a vertical rod, the two ends of the fixed plate are respectively connected to the upper ends of the first towing rod and the second towing rod, the vertical rod is installed on the fixed plate and is slidably connected to the power device in the vertical direction; the lower end of the first towing rod passes through the first cavity of the first support plate and extends into the position connected to the first towing point in the first submerged body, and the inclination angle of the first towing rod is consistent with the inclination angle of the first support plate; the lower end of the second towing rod passes through the second cavity of the second support plate and extends into the position connected to the second towing point in the second submerged body, and the inclination angle of the second towing rod is consistent with the inclination angle of the second support plate.

[0012] In an implementable scheme, the first sheet structure includes a reinforcement frame, the reinforcement frame includes a rib plate and a support frame, the support frame is arranged in the first submersible body and is fixedly connected to the first submersible body, the rib plate is arranged in the first support plate, and the lower end of the rib plate is fixedly connected to the support frame, and the upper end of the rib plate is fixedly connected to the fixed frame beam, the first towing point is located on the support frame, the lower end of the first towing rod is rotatably connected to the support frame, and the rotation axis is perpendicular to the axis of the first submersible body and parallel to the fixed frame beam; the second sheet structure has the same structure as the first sheet structure.

[0013] In an implementable scheme, in the first sheet structure, the support frame of the reinforced frame includes vertical plates at both ends, a connecting rod and a support platform arranged between the two vertical plates, the two vertical plates are connected to the inner wall of the first submersible cavity, the connecting rod is parallel to the axis of the first submersible, the support platform is slidably and fixably mounted on the connecting rod, the lower end of the first towing rod is rotatably connected to the support platform, and the rotation axis is perpendicular to the axis of the first submersible and parallel to the fixed frame beam; the second sheet structure has the same structure as the first sheet structure.

[0014] In an implementable solution, in the first sheet structure, a threaded hole is provided on the first submerged body. After the support platform is adjusted along the connecting rod, a screw is used to cooperate with the threaded hole and tighten the support platform. The second sheet structure has the same structure as the first sheet structure.

[0015] In an implementable scheme, the measuring assembly includes a drag force measuring device, which includes a support body, a vertical sleeve, a tension and pressure sensor, a spring piece, a pneumatic clamp, a slider and a slide rod; the top of the support body is fixedly connected to the power device; the pneumatic clamp and the slide rod are fixed on the support body, and the slide rod is consistent with the longitudinal direction of the small waterplane area catamaran model; the slider is slidably sleeved on the slide rod, and a spring piece is fixedly arranged at each end of the slide rod to prevent the slider from sliding out of the slide rod; one end of the tension and pressure sensor is connected to the slide rod, and the other end is connected to the slider, and the tension and compression direction of the tension and pressure sensor is consistent with the longitudinal direction of the small waterplane area catamaran model, which is used to measure the drag force of the towing device; the vertical sleeve is fixed to one end of the slider, and the vertical rod is inserted into the vertical sleeve to form a sliding fit; when the pneumatic clamp is opened, the slider can slide along the slide rod; when the pneumatic clamp is closed, the slider is clamped to prevent the slider from sliding along the slide rod.

[0016] In an implementable solution, the drag force measuring device further comprises a laser displacement sensor, which is mounted on the support body and directly faces the upper end surface of the vertical rod and is at a predetermined distance therefrom.

[0017] In an implementable solution, the measuring component includes an inclination sensor, which is arranged on a fixed frame beam and is used to measure the longitudinal inclination angle of the small waterplane area catamaran model.

[0018] In an implementable scheme, the anti-lateral shift and roll structure includes a rectangular frame and a guide rod; the rectangular frame is fixedly connected to the fixed frame beam, and a rectangular hole extending longitudinally is provided on the rectangular frame, and the longitudinal center line of the rectangular hole is in the longitudinal section of the middle position of the fixed frame beam, the upper end of the guide rod is fixedly connected to the power device, and the lower end of the guide rod is inserted into the rectangular hole of the rectangular frame.

[0019] According to the second aspect of the present application, a small waterplane area catamaran towing test method is also provided. Using the small waterplane area catamaran towing test device in the above scheme, the test method comprises the following steps:

[0020] According to the actual size of the small waterplane area catamaran, the size of each component of the small waterplane area catamaran model is determined according to a predetermined scale ratio, the first sheet structure and the second sheet structure are fixedly connected to the fixed frame beam according to the proportionally scaled spacing and the actual inclination angle, and the other components are assembled in sequence according to the connection relationship;

[0021] According to the actual draft and buoyancy of the small waterplane area catamaran, the draft and buoyancy of the small waterplane area catamaran model are determined and adjusted according to the predetermined scale ratio;

[0022] According to the formula Determine the towing speed V of the small waterplane area catamaran model m , where λ is the scale ratio, V s is the actual speed of the SWATH ship, and the speed V sSelect a number of speed points at a predetermined interval within a predetermined range, and obtain a number of corresponding drag speeds V m ;

[0023] For several drag speeds V m Conduct a test, start the power device to tow the small waterplane area catamaran model in the test pool according to a predetermined trajectory, and when the small waterplane area catamaran model is accelerated to a set towing speed, at least collect the towing force and the trim angle and heave of the small waterplane area catamaran model to complete a towing speed test, and repeat the above steps until the test of all towing speed points is completed;

[0024] After the test is completed, the collected data is analyzed.

[0025] Compared with the prior art, the beneficial effects of the present application are as follows: in the technical solution of the present application, a small waterplane area catamaran model is formed by using a fixed frame beam and a first sheet structure and a second sheet structure to obtain a scaled model of an actual small waterplane area catamaran. The towing structure is connected downwardly with the intersection of the cross section where the center of gravity of the small waterplane area catamaran model is located and the two thrust axes. On the one hand, the first towing point and the second towing point are formed, and the connecting line of the two towing points constitutes the rotation axis of the small waterplane area catamaran model, ensuring that the model has the degree of freedom of pitching. On the other hand, the towing force is transmitted to the intersection of the thrust axis and the cross section where the center of gravity of the small waterplane area catamaran model is located, realizing the most realistic simulation of the ship's thrust point, so that the trim of the small waterplane area catamaran model can simulate the trim of the real ship, effectively eliminating the serious trim of the model beyond the normal range caused by the unreasonable pushing position, so that the model can truly predict the longitudinal motion performance of the real ship.

[0026] Furthermore, the towing structure is connected to the power device by sliding upward, and the entire towing device can only move up and down along the position of the sliding connection, ensuring that the model has the freedom of heaving. On the one hand, the dragging force generated by the movement of the power device can be transmitted to the position of the towing point through the towing structure. On the other hand, since the small waterplane area catamaran model will produce vertical heave when sailing in the water, the sliding connection between the towing structure and the power device can well bear the vertical heave of the ship model.

[0027] In addition, the solution of this embodiment uses the anti-roll structure to limit the roll of the small waterplane area catamaran model, so that the model basically does not produce unnecessary roll, thereby eliminating the influence of the roll on the accuracy of the longitudinal motion data.

[0028] In summary, the small waterplane area catamaran towing test device of the present embodiment realizes the geometric similarity between the model towing force action point and the real ship thrust action point in vertical height, while ensuring the longitudinal movement freedom of the model's heave and pitch, thereby improving the accuracy of the small waterplane area catamaran towing test and providing technical support for its hydrodynamic performance research. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a schematic diagram of the overall structure of a small waterplane area catamaran towing test device according to an embodiment of the present application;

[0031] Figure 2 It is a structural schematic diagram of a small waterplane area catamaran model and a towing structure according to an embodiment of the present application;

[0032] Figure 3 It is a structural schematic diagram of a small waterplane area catamaran model along a longitudinal perspective according to an embodiment of the present application;

[0033] Figure 4 is a front view structural schematic diagram of a drag force measurement device according to an embodiment of the present application;

[0034] Figure 5 It is a schematic diagram of the three-dimensional structure of a drag force measurement device according to an embodiment of the present application.

[0035] In the figure: 10, small waterplane area catamaran model; 11, fixed frame beam; 111, installation position; 12, first sheet structure; 121, first support plate; 122, first submerged body; 123, first cavity; 13, second sheet structure; 131, second support plate; 132, second submerged body; 133, second cavity; 14, reinforcement frame; 141, rib plate; 142, support frame; 1421, vertical plate; 1422, connecting rod; 1423, support platform; 20, towing device; 21, Power device; 211, trailer bridge measurement; 22, towing structure; 221, first towing rod; 222, second towing rod; 223, fixing plate; 224, vertical rod; 23, anti-lateral shift and roll structure; 231, rectangular frame; 232, guide rod; 30, towing force measuring device; 31, support body; 32, vertical sleeve; 33, tension pressure sensor; 34, spring piece; 35, pneumatic clamp; 36, slider; 37, slide rod; 38, laser displacement sensor; 40, inclination sensor. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0038] First of all, it should be noted that Figure 1 , 2 and 3, the x-axis direction of the coordinate is the horizontal direction, the y-axis direction of the coordinate is the vertical direction, all the longitudinal sections appearing below are planes parallel to the plane where yoz is located, and the cross-sections appearing below are planes parallel to the plane where xoz is located.

[0039] According to the first aspect of the present application, Figure 1-3 As shown, firstly, a small waterplane area catamaran towing test device is provided, which includes a small waterplane area catamaran model, a towing device and a measuring component.

[0040] The small waterplane area catamaran model includes a fixed frame beam 11, a first sheet structure 12 and a second sheet structure 13. The upper end of the first sheet structure 12 is fixedly connected to the right side of the fixed frame beam 11, so that the first sheet structure 12 is tilted at a predetermined angle. The upper end of the second sheet structure 13 is fixedly connected to the left side of the fixed frame beam 11, so that the second sheet structure 13 is tilted at a predetermined angle, and the second sheet structure 13 and the first sheet structure 12 are arranged symmetrically with respect to the longitudinal section of the middle position of the fixed frame beam 11. The towing device includes a power device 21, a towing structure 22 and an anti-lateral shift and heel structure 23. The power device 21 is set above the test pool and is used to move at a predetermined speed along a predetermined trajectory parallel to the water surface. The towing structure 22 is rotatably connected to the first sheet structure 12 and the second sheet structure 13 respectively. The connection between the towing structure 22 and the first sheet structure 12 is the first towing point, and the connection between the towing structure 22 and the second sheet structure 13 is the second towing point. The first towing point and the second towing point are the intersection points of the cross section where the center of gravity of the small waterplane area catamaran model is located and the two thrust axes respectively; the line connecting the first towing point and the second towing point is the axis of the longitudinal rotation of the small waterplane area catamaran model; the towing structure 22 is slidably connected to the power device 21, and the sliding direction is always the vertical direction. The anti-transverse heel structure 23 is used to make the longitudinal axis of the small waterplane area catamaran model always consistent with the forward direction of the power device 21, and to limit the heel rotation of the small waterplane area catamaran model. The measuring component is used to measure the longitudinal heel angle and heave of the small waterplane area catamaran model and the towing force of the towing device.

[0041] In the technical solution of the above embodiment, a small waterplane area catamaran model is formed by using a fixed frame beam 11, a first sheet structure 12 and a second sheet structure 13 to obtain a scaled model of an actual small waterplane area catamaran. The towing structure 22 is connected downwardly to the intersection of the cross section where the center of gravity of the small waterplane area catamaran model is located and the two thrust axes. On the one hand, a first towing point and a second towing point are formed, and the connecting line of the two towing points constitutes the rotation axis of the small waterplane area catamaran model, ensuring that the model has the degree of freedom of pitching. On the other hand, the towing force is transmitted to the intersection of the thrust axis and the cross section where the center of gravity of the small waterplane area catamaran model is located, realizing the most realistic simulation of the ship's thrust point, so that the trim of the small waterplane area catamaran model can simulate the trim of the real ship, effectively eliminating the severe trim of the model beyond the normal range caused by the unreasonable pushing position, so that the model can truly predict the longitudinal motion performance of the real ship.

[0042] Furthermore, the towing structure 22 is connected to the power device 21 by sliding upward, and the entire towing structure 22 can only move up and down along the position of the sliding connection, which ensures that the model has the freedom of heaving. On the one hand, the dragging force generated by the movement of the power device 21 can be transmitted to the position of the towing point through the towing structure 22. On the other hand, since the small waterplane area catamaran model will produce vertical heave when sailing in the water, the sliding connection between the towing structure 22 and the power device 21 can well bear the vertical heave of the ship model.

[0043] In addition, the solution of this embodiment uses the anti-sliding and heeling structure 23 to limit the roll of the small waterplane area catamaran model, so that the model basically does not produce unnecessary heeling, thereby eliminating the influence of heeling on the accuracy of longitudinal motion data.

[0044] In summary, the small waterplane area catamaran towing test device of this embodiment realizes the geometric similarity between the model towing force action point and the actual ship thrust action point in vertical height, while ensuring the longitudinal motion freedom of the model heave and pitch, so that the small waterplane area catamaran model can pitch and heave within a certain range, while limiting the lateral displacement and tilt, and improving the accuracy of the small waterplane area catamaran towing test. Further, with the help of the measurement component, the data such as the longitudinal inclination angle, heave and sinking amount, and towing force of the small waterplane area catamaran model test are obtained to provide technical support for its hydrodynamic performance research.

[0045] It should be noted that if Figure 1 As shown, the power device 21 of the towing device may include a trailer measuring bridge 211, a track and a driving assembly. A track for the movement of the trailer measuring bridge 211 is set up on the test water pool, and then the trailer measuring bridge 211 is installed on the track. The trailer measuring bridge 211 is driven by the driving assembly to move along the track, thereby driving the towing structure 22 to move.

[0046] In one embodiment, Figure 1-3As shown, the first sheet structure 12 includes a first support plate 121 and a first submerged body 122 fixedly connected to the lower end of the first support plate 121, and the upper end of the first sheet structure 12 is fixedly connected to the right side of the fixed frame beam 11, so that the first support plate 121 is tilted at a predetermined angle. The second sheet structure 13 includes a second support plate 131 and a second submerged body 132 fixedly connected to the lower end of the second support plate 131, and the upper end of the second sheet structure 13 is fixedly connected to the left side of the fixed frame beam 11, so that the second support plate 131 is tilted at a predetermined angle, and the second sheet structure 13 and the first sheet structure 12 are symmetrically arranged with respect to the longitudinal section of the middle position of the fixed frame beam 11. The towing structure 22 is rotatably connected to the first submerged body 122 and the second submerged body 132. The connection between the towing structure 22 and the first submerged body 122 is the first towing point, and the connection between the towing structure 22 and the second submerged body 132 is the second towing point. The intersection of the axis of the first submerged body 122 and the cross-section where the center of gravity of the small waterplane area catamaran model is located is the first towing point, and the intersection of the axis of the second submerged body 132 and the cross-section where the center of gravity of the small waterplane area catamaran model is located is the second towing point.

[0047] For the inclined sheet structure of the small waterplane area catamaran, the first support plate 121 and the second support plate 131 can be installed to adjust the inclined angle to the same as the actual ship, so as to simulate the small waterplane area catamaran with different inclined angles. At the same time, by changing the installation position of the first support plate 121 and the second support plate 131 on the fixed frame beam 11, the spacing between the sheet structures can be adjusted to better simulate small waterplane area catamarans of different models.

[0048] In a specific embodiment, Figure 3 As shown, a plurality of mounting positions 111 are provided on the fixed frame beam 11 and are distributed laterally along the main body thereof. The mounting positions 111 of the first sheet structure 12 and the second sheet structure 13 on the fixed frame beam 11 are adjusted to adjust the spacing between the first sheet structure 12 and the second sheet structure 13, thereby adjusting the spacing between the sheet structures to better simulate small waterplane area catamarans of different types.

[0049] In one embodiment, Figure 1As shown, a first cavity 123 is provided in the first support plate 121, and the interior of the first submerged body 122 is a cavity. The first cavity 123 extends from the upper end of the first support plate 121 to the lower end and is connected to the cavity inside the first submerged body 122. A second cavity 133 is provided in the second support plate 131, and the interior of the second submerged body 132 is a cavity. The second cavity 133 extends from the upper end of the second support plate 131 to the lower end and is connected to the cavity inside the second submerged body 132. Further, the towing structure 22 includes a first towing rod 221, a second towing rod 222, a fixing plate 223 and a vertical rod 224. The two ends of the fixing plate 223 are respectively connected to the upper ends of the first towing rod 221 and the second towing rod 222. The vertical rod 224 is installed on the fixing plate 223 and is slidably connected to the power device 21 along the vertical direction. The lower end of the first towing rod 221 passes through the first cavity 123 of the first support plate 121 and extends into the position connected to the first towing point in the first submerged body 122, and the inclination angle of the first towing rod 221 is consistent with the inclination angle of the first support plate 121. The lower end of the second towing rod 222 passes through the second cavity 133 of the second support plate 131 and extends into the position connected to the second towing point in the second submerged body 132, and the inclination angle of the second towing rod 222 is consistent with the inclination angle of the second support plate 131.

[0050] In the above embodiment, the first towing rod 221 and the second towing rod 222 of the towing structure 22 are respectively hidden in the first cavity 123 and the second cavity 133, thereby isolating the towing structure 22 from contact with the water flow, reducing the water flow disturbance caused by the main body structure of the non-small waterplane area catamaran model, and reducing the influence of irrelevant variable factors on the test accuracy.

[0051] In one embodiment, Figure 2 As shown, the first sheet structure 12 includes a reinforcement frame 14, which includes a rib plate 141 and a support frame 142. The support frame 142 is arranged in the first submerged body 122 and is fixedly connected to the first submerged body 122. The rib plate 141 is arranged in the first support plate 121, and the lower end of the rib plate 141 is fixedly connected to the support frame 142. The upper end of the rib plate 141 is fixedly connected to the fixed frame beam 11. The first towing point is located on the support frame 142. The lower end of the first towing rod 221 is rotatably connected to the support frame 142, and the rotation axis is perpendicular to the axis of the first submerged body 122 and parallel to the fixed frame beam 11. The second sheet structure 13 has the same structure as the first sheet structure 12. The reinforcement frame 14 is conducive to strengthening the strength and stability of the sheet structure.

[0052] In one embodiment, Figure 2As shown, in the first sheet structure 12, the support frame 142 of the reinforcement frame 14 includes vertical plates 1421 at both ends, a connecting rod 1422 and a support platform 1423 arranged between the two vertical plates 1421, the two vertical plates 1421 are connected to the inner wall of the cavity of the first submerged body 122, the connecting rod 1422 is parallel to the axis of the first submerged body 122, the support platform 1423 is slidably and fixably installed on the connecting rod 1422, the lower end of the first drag rod 221 is rotatably connected to the support platform 1423, and the rotation axis is perpendicular to the axis of the first submerged body 122 and parallel to the fixed frame beam 11; the second sheet structure 13 has the same structure as the first sheet structure 12. When the towing point is not at the intersection of the cross section where the center of gravity of the small waterplane area catamaran model is located and the thrust axis, or there is an installation error, or the position changes after multiple tests, the position of the support platform 1423 on the connecting rod 1422 can be adjusted, which is equivalent to adjusting the position of the towing point along the thrust axis, so that the towing point is located as much as possible in the cross section where the center of gravity of the small waterplane area catamaran model is located.

[0053] In one embodiment, in the first sheet structure 12, a threaded hole (not shown in the figure) is provided on the first submerged body 122. After the support platform 1423 is adjusted along the connecting rod 1422, a screw (not shown in the figure) is used to cooperate with the threaded hole and tighten the support platform 1423. The second sheet structure 13 has the same structure as the first sheet structure 12. The above is a structure for adjusting the position of the support platform 1423 on the connecting rod 1422.

[0054] In one embodiment, Figure 4 and 5 As shown, the measuring assembly includes a drag force measuring device 30, which includes a support body 31, a vertical sleeve 32, a tension and pressure sensor 33, a spring 34, a pneumatic clamp 35, a slider 36 and a slide bar 37. The top of the support body 31 is fixedly connected to the power device 21. The pneumatic clamp 35 and the slide bar 37 are fixed on the support body 31, and the slide bar 37 is consistent with the longitudinal direction of the small waterplane area catamaran model. The slider 36 is slidably sleeved on the slide bar 37, and a spring 34 is fixedly arranged at both ends of the slide bar 37 to prevent the slider 36 from sliding out of the slide bar 37. One end of the tension and pressure sensor 33 is connected to the slide bar 37, and the other end is connected to the slider 36. The tension and compression direction of the tension and pressure sensor 33 is consistent with the longitudinal direction of the small waterplane area catamaran model, which is convenient for measuring the drag force of the towing device. The vertical sleeve 32 is fixed to one end of the slider 36, and the vertical rod 224 is inserted into the vertical sleeve 32 to form a sliding fit. When the pneumatic clamp 35 is opened, the slider 36 can slide along the slide bar 37 ; when the pneumatic clamp 35 is closed, the slider 36 is clamped so that the slider 36 cannot slide along the slide bar 37 .

[0055] In one embodiment, Figure 4 and 5As shown, the drag force measuring device 30 also includes a laser displacement sensor 38, which is mounted on the support body 31 and directly faces the upper end surface of the vertical rod 224 and is at a predetermined distance, and is used to measure the heave of the small waterplane area catamaran model. Other distance measuring structures or other distance measuring sensors can also be used to measure the heave.

[0056] In one embodiment, Figure 1 and 2 As shown, the measuring assembly includes an inclination sensor 40, which is arranged on the fixed frame beam 11 and is used to measure the longitudinal inclination angle of the small waterplane area catamaran model.

[0057] In an implementation of the anti-lateral shift and roll structure 23, the sliding matching structure of the dragging structure 22 and the power device 21 in the vertical direction can be used as the anti-lateral shift and roll structure 23, and the lateral shift and roll can be limited by sliding only in the vertical direction. Specifically, the vertical rod 224 can be set as a direction, and the vertical sleeve 32 can be a square hole. The cooperation of the two can not only limit the up and down sliding, but also prevent the rotation, so as to limit the occurrence of the model's lateral shift and roll.

[0058] In a preferred embodiment of the anti-sliding and heeling structure 23, as Figure 1 As shown, the anti-lateral shift and roll structure 23 includes a rectangular frame 231 and a guide rod 232. The rectangular frame 231 is fixedly connected to the fixed frame beam 11, and a rectangular hole extending in the longitudinal direction is provided on the rectangular frame 231, and the longitudinal center line of the rectangular hole is in the longitudinal section of the middle position of the fixed frame beam 11. The upper end of the guide rod 232 is fixedly connected to the power device 21, and the lower end of the guide rod 232 is inserted into the rectangular hole of the rectangular frame 231. The cooperation between the guide rod 232 and the rectangular frame 231, on the one hand, prevents the model from generating lateral movement and lateral tilt during the towing test, and on the other hand, does not limit the longitudinal tilt of the model.

[0059] According to the second aspect of the present application, a small waterplane area catamaran towing test method is also provided. Using the small waterplane area catamaran towing test device in the above scheme, the test method comprises the following steps:

[0060] S1. According to the actual size of the small waterplane area catamaran, the size of each component of the small waterplane area catamaran model is determined according to a predetermined scale ratio, the first sheet structure 12 and the second sheet structure 13 are fixedly connected to the fixed frame beam 11 according to the proportionally scaled spacing and the actual inclination angle, and the other components are assembled in sequence according to the connection relationship;

[0061] S2. According to the actual draft and buoyancy of the small waterplane area catamaran, determine and adjust the draft and buoyancy of the small waterplane area catamaran model according to a predetermined scale ratio;

[0062] S3, according to the formula Determine the towing speed V of the small waterplane area catamaran model m , where λ is the scale ratio, V s is the actual speed of the SWATH ship, and the speed V s Select a number of speed points at a predetermined interval within a predetermined range, and obtain a number of corresponding drag speeds V m ;

[0063] S4, successively for several dragging speeds V m Conduct a test, start the power device 21 to tow the small waterplane area catamaran model in the test pool according to a predetermined trajectory, and when the small waterplane area catamaran model is accelerated to a set towing speed, at least collect the towing force and the trim angle and heave of the small waterplane area catamaran model to complete a towing speed test, and repeat the above steps until all towing speed points are tested;

[0064] S5. After the test is completed, analyze the collected data.

[0065] In step S2, the draft and buoyancy of the small waterplane area catamaran model may be adjusted by adding or removing counterweights in the fixed frame beam 11 and / or the first submerged body 122 and the second submerged body 132.

[0066] In the above test, the water temperature of the pool, water density, model weight, center of gravity position, wet surface area, initial trim angle, test speed, towing resistance, etc. can also be collected, and then combined with the towing force, heave and trim angle to obtain the curve of the force, heave and trim angle of the test model changing with the speed, so as to analyze the longitudinal movement of the model.

[0067] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A small waterplane area catamaran towing test device, characterized in that: Includes SWATH model, towing device and measurement kit: The small waterplane area catamaran model comprises: Fixed frame beam (11); A first sheet structure (12), the upper end of which is fixedly connected to the right side of the fixed frame beam (11), so that the first sheet structure (12) is inclined at a predetermined angle; A second sheet structure (13), the upper end of which is fixedly connected to the left side of the fixed frame beam (11), so that the second sheet structure (13) is inclined at a predetermined angle, and the second sheet structure (13) and the first sheet structure (12) are symmetrically arranged with respect to a longitudinal section at a middle position of the fixed frame beam (11); The towing device comprises: A power device (21) is mounted above the test water pool and is used to move along a predetermined trajectory parallel to the water surface at a predetermined speed; A towing structure (22) is rotatably connected to the first sheet structure (12) and the second sheet structure (13), respectively; the connection point between the towing structure (22) and the first sheet structure (12) is a first towing point, and the connection point between the towing structure (22) and the second sheet structure (13) is a second towing point; the first towing point and the second towing point are respectively the intersection points of the cross section where the center of gravity of the small waterplane area catamaran model is located and the two thrust axes; the line connecting the first towing point and the second towing point is the longitudinal tilt rotation axis of the small waterplane area catamaran model; the towing structure (22) is slidably connected to the power device (21), and the sliding direction is always in the vertical direction; An anti-rolling structure (23) is used to ensure that the longitudinal axis of the small waterplane area catamaran model is always consistent with the forward direction of the power device (21) and to limit the heeling rotation of the small waterplane area catamaran model; The measuring assembly is used to measure the trim angle and heave of the small waterplane area catamaran model and the towing force of the towing device; The anti-lateral shift and roll structure (23) comprises a rectangular frame (231) and a guide rod (232); The rectangular frame (231) is fixedly connected to the fixed frame beam (11), and a rectangular hole extending in the longitudinal direction is provided on the rectangular frame (231), and the longitudinal center line of the rectangular hole is located in the longitudinal section of the middle position of the fixed frame beam (11), the upper end of the guide rod (232) is fixedly connected to the power device (21), and the lower end of the guide rod (232) is inserted into the rectangular hole of the rectangular frame (231).

2. The small waterplane area catamaran towing test device according to claim 1, characterized in that: The first sheet structure (12) comprises a first support plate (121) and a first submerged body (122) fixedly connected to the lower end of the first support plate (121); the upper end of the first sheet structure (12) is fixedly connected to the right side of the fixed frame beam (11), so that the first support plate (121) is inclined at a predetermined angle; The second sheet structure (13) comprises a second support plate (131) and a second submerged body (132) fixedly connected to the lower end of the second support plate (131); the upper end of the second sheet structure (13) is fixedly connected to the left side of the fixed frame beam (11), so that the second support plate (131) is inclined at a predetermined angle; the second sheet structure (13) and the first sheet structure (12) are symmetrically arranged with respect to a longitudinal section at a middle position of the fixed frame beam (11); The towing structure (22) is rotatably connected to the first submerged body (122) and the second submerged body (132); the connection point between the towing structure (22) and the first submerged body (122) is a first towing point; the connection point between the towing structure (22) and the second submerged body (132) is a second towing point; the intersection point of the axis of the first submerged body (122) and the cross section where the center of gravity of the small waterplane area catamaran model is located is the first towing point; the intersection point of the axis of the second submerged body (132) and the cross section where the center of gravity of the small waterplane area catamaran model is located is the second towing point.

3. The small waterplane area catamaran towing test device according to claim 1, characterized in that: A plurality of mounting positions (111) are arranged on the fixed frame beam (11) and are distributed laterally along the body thereof, and the mounting positions (111) of the first sheet structure (12) and the second sheet structure (13) on the fixed frame beam (11) are adjusted to adjust the spacing between the first sheet structure (12) and the second sheet structure (13).

4. The small waterplane area catamaran towing test device according to claim 2, characterized in that: A first cavity (123) is arranged inside the first support plate (121), the interior of the first submerged body (122) is a cavity, and the first cavity (123) extends from the upper end to the lower end of the first support plate (121) and is connected to the cavity inside the first submerged body (122); A second cavity (133) is arranged inside the second support plate (131), the interior of the second submerged body (132) is a cavity, and the second cavity (133) extends from the upper end to the lower end of the second support plate (131) and communicates with the cavity inside the second submerged body (132); The towing structure (22) comprises a first towing rod (221), a second towing rod (222), a fixing plate (223) and a vertical rod (224); two ends of the fixing plate (223) are respectively connected to the upper ends of the first towing rod (221) and the second towing rod (222); the vertical rod (224) is mounted on the fixing plate (223) and is slidably connected to the power device (21) along a vertical direction; The lower end of the first towing rod (221) passes through the first cavity (123) of the first support plate (121) and extends into the first submersible body (122) to connect to the first towing point, and the inclination angle of the first towing rod (221) is consistent with the inclination angle of the first support plate (121); The lower end of the second towing rod (222) passes through the second cavity (133) of the second support plate (131) and extends into the second submersible body (132) to connect to the second towing point. The inclination angle of the second towing rod (222) is consistent with the inclination angle of the second support plate (131).

5. The small waterplane area catamaran towing test device according to claim 4, characterized in that: The first sheet structure (12) comprises a reinforcement frame (14), the reinforcement frame (14) comprises a rib plate (141) and a support frame (142), the support frame (142) is arranged in the first submersible body (122) and is fixedly connected to the first submersible body (122), the rib plate (141) is arranged in the first support plate (121), and the lower end of the rib plate (141) is fixedly connected to the support frame (142), and the upper end of the rib plate (141) is fixedly connected to the fixed frame beam (11), the first towing point is located on the support frame (142), the lower end of the first towing rod (221) is rotatably connected to the support frame (142), and the rotation axis is perpendicular to the axis of the first submersible body (122) and parallel to the fixed frame beam (11); The second sheet structure (13) has the same structure as the first sheet structure (12).

6. The small waterplane area catamaran towing test device according to claim 5, characterized in that: In the first sheet structure (12), the support frame (142) of the reinforcement frame (14) includes vertical plates (1421) at two ends, a connecting rod (1422) and a support platform (1423) arranged between the two vertical plates (1421), the two vertical plates (1421) are connected to the inner wall of the cavity of the first submersible body (122), the connecting rod (1422) is parallel to the axis of the first submersible body (122), the support platform (1423) is slidably and fixably mounted on the connecting rod (1422), the lower end of the first dragging rod (221) is rotatably connected to the support platform (1423), and the rotation axis is perpendicular to the axis of the first submersible body (122) and parallel to the fixed frame beam (11); The second sheet structure (13) has the same structure as the first sheet structure (12).

7. The small waterplane area catamaran towing test device according to claim 6, characterized in that: In the first sheet structure (12), a threaded hole is provided on the first submerged body (122), and after the support platform (1423) is adjusted along the connecting rod (1422), a screw is used to cooperate with the threaded hole and tighten the support platform (1423); The second sheet structure (13) has the same structure as the first sheet structure (12).

8. The small waterplane area catamaran towing test device according to any one of claims 4 to 7, characterized in that: The measuring assembly comprises a drag force measuring device (30), wherein the drag force measuring device (30) comprises a support body (31), a vertical sleeve (32), a tension pressure sensor (33), a spring sheet (34), a pneumatic clamp (35), a slider (36) and a slide rod (37); The top of the support body (31) is fixedly connected to the power device (21); The pneumatic clamp (35) and the slide bar (37) are fixed on the support body (31), and the slide bar (37) is consistent with the longitudinal direction of the small waterplane area catamaran model; The slider (36) is slidably sleeved on the slide rod (37), and one spring sheet (34) is fixedly provided at each end of the slide rod (37) to prevent the slider (36) from sliding out of the slide rod (37); One end of the tension and pressure sensor (33) is connected to the slide bar (37), and the other end is connected to the slider (36). The tension and pressure direction of the tension and pressure sensor (33) is consistent with the longitudinal direction of the small waterplane area catamaran model, and is used to measure the towing force of the towing device; The vertical sleeve (32) is fixed to one end of the slider (36), and the vertical rod (224) is inserted into the vertical sleeve (32) to form a sliding fit; When the pneumatic clamp (35) is opened, the slider (36) can slide along the slide bar (37); when the pneumatic clamp (35) is closed, it clamps the slider (36) so that the slider (36) cannot slide along the slide bar (37).

9. The small waterplane area catamaran towing test device according to claim 8, characterized in that: The drag force measuring device (30) further comprises a laser displacement sensor (38), which is mounted on the support body (31) and faces the upper end surface of the vertical rod (224) at a predetermined distance.

10. The small waterplane area catamaran towing test device according to any one of claims 1 to 7, characterized in that: The measuring component comprises an inclination sensor (40), which is arranged on the fixed frame beam (11) and is used to measure the longitudinal inclination angle of the small waterplane area catamaran model.

11. A small waterplane area catamaran towing test method, characterized in that: Using the small waterplane area catamaran towing test device as described in any one of claims 1 to 10, the test method comprises the following steps: According to the actual size of the small waterplane area catamaran, the size of each component of the small waterplane area catamaran model is determined according to a predetermined scale ratio, the first sheet structure (12) and the second sheet structure (13) are fixedly connected to the fixed frame beam (11) according to the proportionally scaled spacing and the actual inclination angle, and the other components are assembled in sequence according to the connection relationship; According to the actual draft and buoyancy of the small waterplane area catamaran, the draft and buoyancy of the small waterplane area catamaran model are determined and adjusted according to the predetermined scale ratio; According to the formula Determine the towing speed V of the small waterplane area catamaran model m , where λ is the scale ratio, V s is the actual speed of the SWATH ship, and the speed V s Select a number of speed points at a predetermined interval within a predetermined range, and obtain a number of corresponding drag speeds V m ; For several drag speeds V m Conducting a test, starting the power device (21) to tow the small waterplane area catamaran model in a test pool along a predetermined trajectory, and when the small waterplane area catamaran model is accelerated to a set towing speed, at least collecting the towing force and the longitudinal inclination angle and heave of the small waterplane area catamaran model to complete a towing speed test, and repeating the above steps until all towing speed points are tested; After the test is completed, the collected data is analyzed.

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