A free oscillation fluid-structure coupling excitation device

Abstract

The utility model provides a kind of free oscillation fluid-solid coupling excitation device, it includes frame and cage;The upper end inside matching of the rack is provided with baffle, upper end one side matching is provided with first fixed release mechanism, the topmost matching is provided with second fixed release mechanism, bottom end is provided with shock-absorbing bottom plate;The cage matching is located in the upper inside of the rack, it is connected with the first fixed release mechanism by the steel wire rope of adjustable length;The first fixed release mechanism is used to fix or release the cage, so that it does pendulum motion and stops after moving to touch the baffle;The second fixed release mechanism is used to fix or release the cage, so that it does free fall motion, until it falls into the shock-absorbing bottom plate.The utility model structure design is simple, reasonable, easy to operate and use, can realize the process of studying tank body movement posture under microgravity state.

Description

Technical Field

[0001] This utility model relates to the field of mechanical manufacturing technology, specifically to a free oscillation fluid-structure coupling excitation device. Background Technology

[0002] Studying the motion and attitude of the propellant tank is of great significance in the study of microgravity fluid management. It not only helps optimize propellant management and improve spacecraft control precision, but also addresses new challenges in microgravity fluid management, promoting the development of space science and technology. However, previous tank experiments only involved free fall tests, rarely applying a directional excitation to the tank before its descent. Previous excitation methods typically used spring triggers, which have drawbacks such as difficulty in controlling the magnitude and direction of the spring force and high cost.

[0003] Currently, in the research of microgravity fluid management, the existing technical means for studying the motion attitude of tanks mainly include the following: (1) Numerical simulation: Predicting and analyzing the fluid behavior of tanks under microgravity through computer simulation. This method can provide detailed fluid dynamics information, but its accuracy depends on the precision of the model and the setting of boundary conditions. The model is complex and requires high computational resources, and a large number of verification experiments are needed to ensure the reliability of the simulation results. In addition, for complex fluid behavior, existing numerical models may not be able to fully capture all the details.

[0004] (2) Ground-based experiments: Short-term microgravity environments are created on the ground using methods such as parabolic flight, drop towers, or water tank simulations to observe the motion of the tank. Although these methods can provide real microgravity data, the experimental time and conditions are limited, making it difficult to fully reflect the situation under long-term microgravity conditions. The microgravity time provided is also short, usually only a few seconds to tens of seconds, making it difficult to simulate the phenomena under long-term microgravity conditions. In addition, the conditions of ground-based experiments differ from the actual space environment, which may lead to deviations in the experimental results.

[0005] (3) Space experiments: Experiments are conducted on the International Space Station or other spacecraft to directly observe and record the motion and attitude of the tank in a microgravity environment. This method is the most direct, but it is costly, has limited experimental opportunities, and is complex in terms of experimental design and implementation. In addition, data collection and analysis in space experiments are relatively difficult, requiring overcoming problems such as communication delays and data transmission. In summary, although existing technologies can help researchers understand fluid management issues in microgravity environments to some extent, many challenges remain, requiring further research and development of new technologies to address these problems. Summary of the Invention

[0006] To address the technical problems existing in the background art mentioned above, this utility model proposes a free oscillation fluid-structure coupling excitation device with a simple and reasonable structural design, convenient operation and use, which can realize the process of studying the motion posture of the tank under microgravity.

[0007] To solve the above-mentioned technical problems, this utility model provides a free-oscillating fluid-structure interaction excitation device, which includes a frame and a cage. A baffle is fitted inside the upper end of the frame, a first fixing and release mechanism is fitted on one side of the upper end, a second fixing and release mechanism is fitted at the top, and a shock-absorbing base plate is fitted at the bottom. The cage is located inside the upper part of the frame and is connected to the first fixing and release mechanism via an adjustable-length steel wire rope. The first fixing and release mechanism is used to fix or release the cage, causing it to perform a pendulum motion and stop after touching the baffle. The second fixing and release mechanism is used to fix or release the cage, causing it to perform free-fall motion until it falls into the shock-absorbing base plate.

[0008] The free oscillation fluid-structure coupling excitation device includes: both the first fixed release mechanism and the second fixed release mechanism are electromagnetic release devices; the first fixed release mechanism is magnetically connected to the cage; and the second fixed release mechanism is magnetically connected to the wire rope.

[0009] The free oscillation fluid-structure interaction excitation device includes: a storage tank for holding liquid is matched at the center of the cage; a motion camera for observing the movement state of the liquid is matched on one side; a light source for providing illumination is matched at the center below the top; and an attitude sensor for measuring the movement attitude of the storage tank is matched at the center of the bottom.

[0010] The free oscillation fluid-structure coupling excitation device includes a hook positioned at the center of the top of the cage; the hook connects to the wire rope and is connected to the first fixed release mechanism via the wire rope.

[0011] The free-oscillating fluid-structure interaction excitation device comprises: a frame that is generally rectangular in shape, including a bottom frame, an assembly frame, a top frame, and a baffle; the bottom frame is horizontally arranged on the ground, with the shock-absorbing base plate fixedly installed on its upper part, and vertical columns fixedly installed around its circumference or at its four corners; the assembly frame is horizontally installed on the upper middle section of the columns; the top frame is horizontally installed on the top of the columns; and the baffle is vertically installed on the upper side of one side of the assembly frame and below the top frame.

[0012] The free oscillation fluid-structure interaction excitation device, wherein: the first fixed release mechanism is matched and installed on the column above the assembly hole via a mounting bracket.

[0013] The free oscillation fluid-structure coupling excitation device, wherein: the second fixed release mechanism is matched and installed in the center of the upper part of the top frame.

[0014] The free oscillation fluid-structure interaction excitation device, wherein: the cage is fitted and installed in the space between the assembly frame and the top frame.

[0015] By adopting the above technical solution, this utility model has the following beneficial effects: This invention relates to a free-oscillating fluid-structure interaction excitation device. It features a simple and reasonable structural design, easy and convenient operation, and flexible adjustment. Used in microgravity drop tower facilities, it is a research device for studying microgravity fluid management and is a specialized research equipment used to generate excitation devices. This invention is the first of its kind in China. Primarily installed in a microgravity drop tower facility, this device releases the tested container under microgravity conditions, causing it to swing in a pendulum-like manner. The lowest point of this swing generates a horizontal collision excitation, thus disturbing the fluid inside the container. Upon release, the container falls freely, allowing for the study of its motion.

[0016] This invention belongs to the category of drop tower experiments within ground-based testing. Although the microgravity time is relatively short, it is sufficient for observation in certain experiments. It generates a lateral excitation before the tank falls, causing the liquid inside to slosh. This, combined with the free fall motion, creates a free sloshing effect on the tank wall, which can be used to study the influence of the liquid surface on the tank wall. The magnitude of the lateral excitation can be adjusted by the length of the steel cable, meaning the excitation magnitude can be adjusted according to the experimental conditions. This invention employs a pendulum structure, ensuring consistency in each motion and maintaining the excitation direction parallel to the liquid surface at the moment of impact at the bottom, facilitating subsequent numerical calculations. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the free oscillation fluid-structure coupling excitation device of this utility model; Figure 2 This is a schematic diagram of the cage structure of the free oscillation fluid-structure coupling excitation device of this utility model. Detailed Implementation

[0019] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] The present invention will be further explained below with reference to specific embodiments.

[0021] like Figure 1-2 As shown in the figure, the free oscillation fluid-structure coupling excitation device provided in this embodiment includes a frame 1 and a cage 2.

[0022] The frame 1 is a rectangular frame structure, including a bottom frame 11, an assembly frame 12, a top frame 13, a baffle 14, a first fixing release mechanism 15, and a second fixing release mechanism 16. The bottom frame 11 is horizontally positioned on the ground, with a shock-absorbing base plate fixedly installed on its upper part, and vertically fixed columns 111 at its circumference or four corners. The assembly frame 12 is horizontally installed on the upper middle section of the columns 111. The top frame 13 is horizontally installed on the top of the columns 111. The baffle 14 is vertically installed on one side of the assembly frame 12 and below the top frame 13. The first fixing release mechanism 15 is installed on the column 111 above the assembly hole 12 via a mounting bracket 151. The second fixing release mechanism 16 is installed at the upper center of the top frame 13. Both the first fixing release mechanism 15 and the second fixing release mechanism 16 are electromagnetic release devices.

[0023] The cage 2 is installed in the space between the assembly frame 12 and the top frame 13 of the frame 1. A liquid storage tank 22 is centrally located inside the cage. A motion camera 23 for observing the liquid's movement is located on one side. A light source 25 for illumination is located at the center of the bottom of the cage. A hook 26 is located at the center of the top, and an attitude sensor 24 for measuring the movement of the storage tank 22 is located at the center of the bottom. The hook 26 of the cage 2 is connected to a steel wire rope 21, which is magnetically connected to a first fixed release mechanism 16 on the frame 1. The cage 2 is magnetically connected to the first fixed release mechanism 15.

[0024] In actual use, the free oscillation fluid-structure coupling excitation device of this utility model is installed as a whole on the landing capsule.

[0025] The working principle of this utility model: The cage 2 is fixed by a fixed release mechanism 1, and the other end of the cage 2 is connected to a second fixed release mechanism 16 via a steel wire rope 21 and a hook 26. At the start of the experiment, the first fixed release mechanism 15 first releases the cage 2, which then moves in a pendulum motion and touches the baffle 14 before stopping. Simultaneously, the second fixed release mechanism 16 opens, and the cage 2 falls freely until it lands on the shock-absorbing base plate. The release of the cage 2 by the first fixed release mechanism 15 creates a pendulum motion that, upon colliding with the baffle 14, generates a horizontal excitation. The change in the liquid distribution inside the tank 22 is caused by this excitation, resulting in free movement and a reaction effect on the liquid, exhibiting a fluid-structure interaction effect. During the experiment, the motion of the fluid / interface inside the tank 22 is observed and recorded by a motion camera 23, the motion attitude of the cage 2 itself is inverted using an attitude sensor 24, and the motion state of the tank 22 is inverted by combining the positioning observation of the tank 22 itself.

[0026] This utility model has a simple and reasonable structural design, is easy to operate and use, and can realize the process of studying the motion posture of the tank under microgravity.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A free oscillating fluid-structure coupling excitation device, characterized by: The excitation device includes a frame (1) and a cage (2); The frame (1) is equipped with a baffle (14) inside the upper end, a first fixed release mechanism (15) is matched on one side of the upper end, a second fixed release mechanism (16) is matched at the top, and a shock-absorbing base plate is provided at the bottom. The cage (2) is located on the upper inner side of the frame (1) and is connected to the first fixed release mechanism (15) by a steel wire rope (21) of adjustable length. The first fixed release mechanism (15) is used to fix or release the cage (2) so that it makes a pendulum motion and stops after it touches the baffle (14); The second fixed release mechanism (16) is used to fix or release the cage (2) so that it can fall freely until it falls into the shock-absorbing base plate.

2. The free oscillation fluid-structure coupling excitation device of claim 1, wherein: Both the first fixed release mechanism (15) and the second fixed release mechanism (16) are electromagnetic release devices; the first fixed release mechanism (15) is magnetically connected to the cage (2); the second fixed release mechanism (16) is magnetically connected to the wire rope (21).

3. The free oscillation fluid-structure coupling excitation device of claim 1, wherein: The cage (2) has a storage tank (22) for holding liquid at its center, a motion camera (23) for observing the movement of liquid at one side, a light source (25) for providing illumination at the center below the top, and an attitude sensor (24) for measuring the movement posture of the storage tank (22) at the center of the bottom.

4. The free oscillation fluid-structure coupling excitation device of claim 3, wherein: A hook (26) is provided at the center of the top of the cage (2); the hook (26) is connected to the wire rope (21) and is connected to the second fixed release mechanism (16) through the wire rope (21).

5. The free oscillation fluid-structure coupling excitation device of claim 3, wherein: The frame (1) is a rectangular frame structure, which also includes a bottom frame (11), an assembly frame (12), a top frame (13) and a baffle (14). The bottom frame (11) is horizontally arranged on the ground, and the shock-absorbing base plate is fixedly installed on its upper part. Columns (111) are vertically fixedly installed around the perimeter or at the four corners. The assembly frame (12) is horizontally installed on the upper middle section of the column (111); The top frame (13) is horizontally installed on the top of the column (111); The baffle (14) is vertically positioned on the upper part of one side of the assembly frame (12) and below the top frame (13).

6. The free oscillation fluid-structure coupling excitation device of claim 5, wherein: The first fixed release mechanism (15) is matched and installed on the column (111) on one side above the assembly frame (12) via the mounting bracket (151).

7. The free oscillation fluid-structure coupling excitation device of claim 5, wherein: The second fixed release mechanism (16) is matched and installed in the upper center of the top frame (13).

8. The free oscillation fluid-structure coupling excitation device of claim 5, wherein: The cage (2) is fitted into the space between the assembly frame (12) and the top frame (13).

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