Device for measuring fluid acting force borne by solid spherical particles

Abstract

The invention provides a device for measuring fluid acting force borne by solid spherical particles. The device comprises a water tank, a water pump is arranged in the water tank, the output end of the water pump is connected with one end of a water supply pipe, the other end of the water supply pipe is connected with one end of a water tank, a supporting plate is arranged at the top of the water tank, and a tension meter is arranged at the top of the supporting plate. One end of a fine line is mounted on the tension meter, a smooth cross rod is fixedly mounted on the water tank, the fine line is in contact with the smooth cross rod, and a small experimental ball is fixedly mounted at one end, far away from the tension meter, of the fine line. The device for measuring the fluid acting force borne by the solid spherical particles has the advantages of being simple in equipment, convenient to install, small in influence on fluid around the particles, higher in measurement precision and capable of achieving measurement of the fluid acting force borne by the solid particles under various experiment conditions.

Description

Technical Field

[0001] The invention relates to the technical field of measuring fluid forces exerted on solid particles, and in particular to a device for measuring fluid forces exerted on solid spherical particles. Background Art

[0002] When sediment accumulates in the river, it raises the riverbed, reduces the flow capacity of the river, and increases the risk of flooding. There is a certain amount of sediment on the surface of urban roads. A large amount of nitrogen, phosphorus and other substances are adsorbed on the surface of the sediment, which will enter the urban drainage pipes with rainwater. These sediments are deposited in the pipes and are an important factor affecting the flow capacity of the pipes and the water quality of the river. How to effectively predict the force of water flow on sediment and determine the critical motion state of this sediment in order to provide the best parameters for engineering design has become the research focus of scientific research and engineering personnel. In addition, in the study of fluid-solid coupling, the force of fluid on solid is the key to solving the coupling equation and predicting the motion trajectory and motion law of solid particles.

[0003] Current measurement technology:

[0004] Technique 1: Observe the movement of particles of different sizes in the sedimentation tube. By solving the mechanical equilibrium equation of the particles in a uniform motion state, the fluid resistance of the particles under the sedimentation conditions is obtained. Based on further analysis, the resistance law of the particles is obtained.

[0005] Technology 2: By connecting the particles to the sensor, placing the test device at the bottom of the water tank, and measuring the force on the ball under different experimental conditions, the resistance law of the particles is obtained.

[0006] Due to the complexity of fluid motion, the relative speed between solid particles and fluid is not always equal to the particle's sinking speed. In previous studies, the fluid force law obtained based on particle sinking speed tests is not applicable to the force analysis of particles under non-sinking speed conditions, and it is impossible to determine the relationship between the two components of fluid force, namely the drag force and the lifting force. In addition, by connecting the sensor to the particle, the size of the sensor is generally larger than the size of the particle, which causes greater interference to the fluid around the particle.

[0007] Therefore, it is necessary to provide a new device for measuring the fluid force acting on solid spherical particles to solve the above technical problems. Summary of the invention

[0008] The technical problem solved by the present invention is to provide a fluid force measuring device for solid spherical particles, which has simple equipment, easy installation, little influence on the fluid around the particles, higher measurement accuracy, and can measure the fluid force exerted on the solid particles under various experimental conditions.

[0009] In order to solve the above technical problems, the fluid force measuring device for solid spherical particles provided by the present invention comprises: a water tank, a water pump is arranged in the water tank, the output end of the water pump is connected to one end of a water supply pipe, the other end of the water supply pipe is connected to one end of a water tank, a support plate is arranged on the top of the water tank, a tensile gauge is arranged on the top of the support plate, one end of a thin wire is installed on the tensile gauge, a smooth cross bar is fixedly installed on the water tank, the thin wire is in contact with the smooth cross bar, and an experimental ball is fixedly installed on the end of the thin wire away from the tensile gauge.

[0010] Preferably, a flow meter and a first valve are provided on the water supply pipe.

[0011] Preferably, a plurality of energy dissipation plates are provided in the water tank.

[0012] Preferably, the water tank is provided with a water inlet pipe, and the water inlet pipe is provided with a second valve.

[0013] Preferably, a rotating shaft is provided at the bottom of the water tank, and the rotating shaft is in contact with the bottom of the water tank.

[0014] Preferably, a jack is provided at the bottom of the water tank, and a supporting platform is provided at the bottom of the jack.

[0015] Preferably, the other end of the water tank is located above the water tank, and a water tank tailgate is installed at the other end of the water tank.

[0016] Preferably, it also includes a camera, which is facing the experimental ball.

[0017] Compared with the related art, the device for measuring the fluid force acting on solid spherical particles provided by the present invention has the following beneficial effects:

[0018] The invention provides a device for measuring the fluid force exerted on solid spherical particles, which has little influence on the fluid environment around the particles, has high measurement accuracy, and can realize the measurement of the fluid force exerted on the solid particles under various experimental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a preferred embodiment of a device for measuring the fluid force acting on solid spherical particles provided by the present invention;

[0020] Figure 2 for Figure 1 The schematic diagram of the top view structure shown;

[0021] Figure 3 Schematic diagram of the forces acting on particles in a fluid.

[0022] Numbers in the figure: 1. water tank, 2. water pump, 3. water supply pipe, 4. flow meter, 5. water tank, 6. support plate, 7. dynamometer, 8. smooth cross bar, 9. thin wire, 10. experimental ball, 11. support platform, 12. jack, 13. rotating shaft, 14. first valve, 15. energy dissipation plate, 16. water inlet pipe, 17. second valve, 18. tailgate of water tank, 19. camera. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0024] Please refer to Figure 1 , Figure 2 and Figure 3 ,in, Figure 1 A schematic structural diagram of a preferred embodiment of a device for measuring the fluid force acting on solid spherical particles provided by the present invention; Figure 2 for Figure 1 The schematic diagram of the top view structure shown; Figure 3 The schematic diagram of the force acting on particles in the fluid is shown in FIG. The device for measuring the fluid force acting on solid spherical particles comprises: a water tank 1, a water pump 2 is arranged in the water tank 1, the output end of the water pump 2 is connected to one end of a water supply pipe 3, the other end of the water supply pipe 3 is connected to one end of a water tank 5, a support plate 6 is arranged on the top of the water tank 5, a tensiometer 7 is arranged on the top of the support plate 6, one end of a thin wire 9 is installed on the tensiometer 7, a smooth crossbar 8 is fixedly installed on the water tank 1, the thin wire 9 is in contact with the smooth crossbar 8, and an experimental ball 10 is fixedly installed on the end of the thin wire 9 away from the tensiometer 7.

[0025] The water supply pipe 3 is provided with a flow meter 4 and a first valve 14 .

[0026] A plurality of energy dissipation plates 15 are disposed in the water tank 5 .

[0027] The water tank 1 is provided with a water inlet pipe 16 , and the water inlet pipe 16 is provided with a second valve 17 .

[0028] A rotating shaft 13 is provided at the bottom of the water tank 5 , and the rotating shaft 13 is in contact with the bottom of the water tank 5 .

[0029] A jack 12 is provided at the bottom of the water tank 5 , and a supporting platform 11 is provided at the bottom of the jack 12 .

[0030] The other end of the water tank 5 is located above the water tank 1 , and a water tank tailgate 18 is installed at the other end of the water tank 5 .

[0031] The device further comprises a camera 19 , which faces the experimental ball 10 .

[0032] In this embodiment, it mainly includes a water pump 2, a flow control and monitoring system, a water tank 5, a water tank 1, a smooth cross bar 8, a high-precision digital dynamometer 7, etc. The water tank 5 is a variable slope circulation water tank, and organic glass plates are installed on the wall and the bottom. The slope is adjustable. The water tank 5 is connected by upstream and downstream transition sections and a middle observation section. The flow rate is adjusted by the first valve 14 on the water supply pipe 3; a two-stage honeycomb rectifier plate (energy dissipation plate 15) is installed at the upstream water inlet of the water tank for energy dissipation; an adjustable water tank tail gate 18 is installed at the tail of the water tank 5. The specific structural settings are as follows: Figure 1 and Figure 2 :

[0033] The measuring principle of the present invention is: according to the relationship between the direction of force and the direction of water flow, the fluid force is divided into drag force and lifting force. When the movement of particles lags behind the movement of fluid, the fluid force promotes the movement of particles, which is called drag force. When the movement of fluid lags behind the movement of particles, the fluid force hinders the movement of particles, which is called resistance. In fact, there is no difference in the formation mechanism between drag force and resistance, and the direction is opposite to the related movement direction between particles and water flow. When particles rotate in the fluid or are sheared by the fluid, the particles will also be affected by the lifting force, and the direction of the force is perpendicular to the direction of the drag force (resistance). The forces acting on particles in the fluid mainly include underwater gravity (G), drag force (F d ) and lifting force (F s ) In order to calculate the fluid force on the particles, an external pulling force (F s ), which makes the ball achieve mechanical balance. The schematic diagram of the force acting on the ball in the fluid in the experiment is as follows Figure 3 shown.

[0034] The mechanical analysis of the test ball yields two equilibrium equations:

[0035] x-direction F d =F s cosθ

[0036] y to F l =GF s sinθ

[0037] The measurement process of the present invention is as follows:

[0038] 1. Adjust the flow rate according to the experimental design;

[0039] 2. When the water flow is stable, connect the test ball 10 with the thin wire 9 to the dynamometer 7;

[0040] 3. Adjust the position of the support plate 6 where the dynamometer 7 is located to ensure that the test ball 10 is in the center of the water tank 5;

[0041] 4. Use the camera 19 to take a picture of the relative position of the experimental ball 10 and the thin wire 9 from the side of the water tank 5 to obtain an experimental picture;

[0042] 5. Process the experimental pictures and extract the angle θ between the thin line and the direction of gravity;

[0043] 6. Perform force analysis on the test ball 10 to obtain the F d 、F l .

[0044] Compared with the related art, the device for measuring the fluid force acting on solid spherical particles provided by the present invention has the following beneficial effects:

[0045] The invention provides a device for measuring the fluid force exerted on solid spherical particles, which has little influence on the fluid environment around the particles, has high measurement accuracy, and can realize the measurement of the fluid force exerted on the solid particles under various experimental conditions.

[0046] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A device for measuring the fluid force acting on solid spherical particles, characterized in that: include: A water tank, wherein a water pump is arranged in the water tank, an output end of the water pump is connected to one end of a water supply pipe, the other end of the water supply pipe is connected to one end of a water tank, a support plate is arranged on the top of the water tank, a dynamometer is arranged on the top of the support plate, one end of a thin wire is installed on the dynamometer, a smooth cross bar is fixedly installed on the water tank, the thin wire is in contact with the smooth cross bar, and an experimental ball is fixedly installed on the end of the thin wire away from the dynamometer.

2. The device for measuring the fluid force acting on solid spherical particles according to claim 1, characterized in that: The water supply pipe is provided with a flow meter and a first valve.

3. The device for measuring the fluid force acting on solid spherical particles according to claim 1, characterized in that: A plurality of energy dissipation plates are arranged in the water tank.

4. The device for measuring the fluid force acting on solid spherical particles according to claim 1, characterized in that: The water tank is provided with a water inlet pipe, and the water inlet pipe is provided with a second valve.

5. The device for measuring the fluid force acting on solid spherical particles according to claim 1, characterized in that: A rotating shaft is provided at the bottom of the water tank, and the rotating shaft is in contact with the bottom of the water tank.

6. The device for measuring the fluid force acting on solid spherical particles according to claim 1, characterized in that: A jack is arranged at the bottom of the water tank, and a supporting platform is arranged at the bottom of the jack.

7. The device for measuring the fluid force acting on solid spherical particles according to claim 1, characterized in that: The other end of the water tank is located above the water tank, and a water tank tailgate is installed at the other end of the water tank.

8. The device for measuring the fluid force acting on solid spherical particles according to claim 1, characterized in that: Also included is a camera, which is facing the experimental ball.

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