CN209765842U - Accurate reynolds experimental instrument - Google Patents

Abstract

The utility model discloses an accurate reynolds experimental apparatus, through install the thin pointer of gliding reading from top to bottom in the middle of the elevation reading chi, as long as during concrete reading the thin pointer of reading slides and just can accurate reading to corresponding liquid level height department, in addition at the experiment pipe rear end installation fine setting rivers valve, rotate fine setting rotatory pointer valve alright 45 in the front and accomplish the coarse adjustment of rotatory 5 at every turn under the state that rivers valve is wide open, 45 at the back accomplish the fine setting of rotatory 1 at every turn, thereby can observe turbulent flow and laminar flow different states and take notes corresponding abundant data, through linking to each other water catch basin and drainage system, the low level water tank links to each other with water supply system, the mixed water reflux who has avoided containing the color water reuses the problem that influences the observation result, the reynolds experimental apparatus has overcome the big experimental error that generally exists in the reynolds experimental apparatus in the past, The precision is low, and the operation is greatly facilitated while the accurate experiment is realized.

Description

An Accurate Reynolds Experimental Apparatus

technical field

The utility model relates to an experimental instrument, in particular to an accurate Renault experimental instrument.

Background technique

The Reynolds experiment is one of the most important experiments in hydraulic experiments and teaching, but the Reynolds experimental instruments in the laboratory generally have problems such as large measurement errors and low precision. These problems mainly come from the following aspects: First, the measurement of pressure difference When calculating the height, most of them use the visual method or the horizontal ruler to read, which is time-consuming and laborious and causes a large reading error; the second is that the ordinary water flow valve at the back end of the experimental tube is difficult to control, and a small force often results in a large turning angle. As a result, the measured data in the experiment is less, and sometimes the laminar flow phenomenon cannot be observed, which greatly reduces the effect and accuracy of the experiment; the third is that when measuring the flow, the volume of the water is often measured manually with a measuring cylinder and the time is measured with a stopwatch, and the two are very different. It is difficult to carry out synchronously, coupled with the error of measurement and timing, it will lead to a large error in the whole experiment; the fourth is that the water in the sump in the experiment must return to the low-level water tank, and then pressurized by the water pump in the low-level water tank To the constant pressure water tank, but because the mixed water containing colored water is reused, this will affect the observation of subsequent experiments and easily cause inaccurate experimental results. Aiming at these problems, there is an urgent need for an accurate Reynolds experimental instrument.

Utility model content

The purpose of the utility model is to overcome the deficiencies in the prior art and provide an accurate Reynolds experimental instrument, which effectively solves the problem of the large error in the elevation reading of the differential pressure gauge, the difficulty in controlling the ordinary water flow valve at the back end of the experimental pipeline, and the complicated and difficult process of measuring the flow rate. A series of problems that affect the accuracy of Reynolds experiments, such as large errors and the reflow of mixed water containing colored water, which affect the observation results.

In order to solve the above technical problems, the utility model is realized through the following technical solutions:

A precise Reynolds experimental instrument, including: a test bench, a low-level water tank installed on the lower left of the test bench, a constant-pressure water tank installed on the upper left of the test bench, an upper water pipe and a lower water pipe are installed between the low-level water tank and the constant-pressure water tank, The upper water pipe is connected with the water pump to pump the water in the lower water tank into the constant pressure water tank. The pumped water flows into the experimental tube through the porous partition, and the overflowing water flows to the left side of the constant pressure water tank through the large partition. It flows back to the low-level water tank from the downpipe. A color water tank containing experimental color water is installed in the constant-pressure water tank. A thin tube is connected under the color water tank. The differential pressure gauge of the reading scale is connected to the orifice flowmeter. A fine-tuning water flow valve is installed at the rear end of the test tube. The end of the test tube is bent downward by 90° and extends a part to form a drain. Laboratory drainage system discharges mixed water with colored water.

The left side of the low-level water tank is connected to the water inlet pipe, and the water inlet pipe is connected to the laboratory water supply system. There is an on-off valve to control the closure, and a float valve to control the water supply on the right end. The right side of the low-level water tank is slightly higher than the water inlet pipe. It is connected to the overflow pipe, and the bottom of the right side of the low-level water tank is connected to the drain pipe. On the drain pipe, a switch valve for controlling closure is installed. Both the overflow pipe and the drain pipe are connected to the laboratory drainage system.

A thin tube with a switch valve is connected under the color water tank. The lower end of the thin tube is bent at 90° and extends to the outlet of the constant pressure water tank. The top of the thin tube is provided with a slender needle, and the slender needle extends into the left side of the test tube. There is a pulse injector at the end of the thin tube at the side trumpet-shaped interface.

The differential pressure gauge is equipped with a corresponding elevation reading scale. The elevation reading scale is perpendicular to the test bench and has a data scale. A thin pointer for reading that can slide up and down is installed in the middle. The differential pressure gauge is connected to the experimental tube through a thin hose.

The orifice flowmeter is equipped with a corresponding elevation reading ruler. The elevation reading ruler is perpendicular to the test bench and is provided with a data scale. A thin pointer for reading that can slide up and down is installed in the middle. There is an orifice plate with a central round hole in the tube, the orifice expands from front to back, and the side is at an angle of 45° to the axis of the tube.

The fine-tuning rotary pointer valve is installed on the fine-tuning water flow valve, which can realize the rotation of 90°. The front 45° of the fine-tuning water flow valve panel is a 5° coarse-tuning area, and the rear 45° is a 1° fine-tuning area.

The experimental tube is made of glass and used to observe laminar turbulent flow phenomena.

Compared with the prior art, the beneficial effect of the utility model is: the experimental model is equipped with a reading fine pointer that can slide up and down in the middle of the elevation reading scale, and the specific reading only needs to slide the reading fine pointer to the corresponding liquid level height The fine-tuning water flow valve installed at the back end of the test tube can complete the rough adjustment of each rotation of 5° in the first 45° by turning the fine-tuning rotary pointer valve when the water flow valve is fully open, and the rear 45° °Complete the fine-tuning of each rotation of 1°, so that different states of turbulent flow and laminar flow can be observed and corresponding enough data can be recorded to improve the effect and accuracy of the experiment. In order to avoid various errors caused by manual operation when measuring flow, The experimental instrument is equipped with an orifice flowmeter, which can accurately obtain the flow rate in the experimental tube. By connecting the sump with the drainage system and the low-level water tank with the water supply system, it is avoided that the mixed water containing colored water is re-used to affect the observation results. The Renault experimental instrument overcomes the common problems of large experimental errors and low precision in previous Renault experimental instruments, and greatly facilitates the operation while achieving accurate experiments.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the utility model.

Fig. 2 is the schematic diagram of differential pressure gauge and elevation reading scale of the present utility model.

Fig. 3 is a schematic diagram of the orifice flowmeter and the elevation reading scale of the present invention.

Fig. 4 is a schematic diagram of the fine-tuning water flow valve of the present invention.

Meanings of icons: 1-test bench; 2-constant pressure water tank; 3-big partition; 4-porous partition; 5-color water tank; 6-switch valve three; 7-thin tube; 8-pulse injector ;9-experiment tube; 10-differential pressure gauge; 11-elevation reading ruler one; 12-orifice plate flowmeter; 13-elevation reading ruler two; 14-fine-tuning water flow valve; -Upper water pipe; 18-Down water pipe; 19-Suction pump; 20-Inlet pipe; 21-Switch valve one; 22-Float valve; 23-Overflow pipe; Fine pointer 1; 1201-orifice plate; 1301-reading fine pointer 2; 1401-5° coarse adjustment area; 1402-1° fine adjustment area; 1403-fine adjustment rotary pointer valve.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail.

As shown in Figure 1, a kind of precise Reynolds experimental apparatus comprises: test bed 1, the low water tank 16 that is installed in the lower left side of test bed 1, the constant pressure water tank 2 that is installed in the upper left side of test bed 1, low water tank 16 and constant An upper water pipe 17 and a lower water pipe 18 are installed between the pressurized water tanks 2, and the upper water pipe 17 is connected to the water pump 19 so as to pump the water in the lower water tank 16 into the constant pressure water tank 2, and the drawn water flows into the experimental chamber through the porous partition 4. pipe 9, and the overflowing water then flows to the left side of the constant pressure water tank 2 through the large partition 3 so as to flow back to the low water tank 16 by the downpipe 18, and a color water tank of the color used for experiments is installed in the said constant pressure water tank 2. The water tank 5 and the color water tank 5 are connected with a thin tube 7, and the water outlet of the constant pressure water tank 2 is connected with the test tube 9, and the test tube 9 is connected with the differential pressure gauge 10 and the orifice flowmeter 12 with the elevation reading ruler 11 successively, A fine-tuning water flow valve 14 is installed at the rear end of the test tube 9. The end of the test tube 9 is bent downward by 90° and extends a part to form a drain. A sump 15 is placed under the drain. The sump 15 discharges colored water through the laboratory drainage system. of mixed water.

The left side of the low-level water tank 16 is connected to the water inlet pipe 20, and the water inlet pipe 20 is connected to the laboratory water supply system. There is a ball float valve 22. When the water volume in the low-level water tank 16 reaches a certain level, the ball-float valve 22 floats up to stop the water intake. The right side of the low-level water tank 16 is connected to the overflow pipe 23. The installation height of the overflow pipe is slightly higher than the water inlet pipe 20 to prevent the low-level water tank from The water level in 16 is too high and overflows on the laboratory floor, and the bottom of the right side of the low-level water tank 16 is connected to the drain pipe 24, and the on-off valve 25 for controlling closure is installed on the drain pipe, and the overflow pipe 23 and the drain pipe 24 are all connected to the laboratory drain. The system is connected, and when the experiment is finished, close the water inlet pipe switch valve 21, open the drain pipe switch valve 25, and discharge the remaining water.

The color water tank 5 is connected with a thin tube 7 with an on-off valve 6. When the liquid level in the constant pressure water tank 2 is stable, the on-off valve 6 on the thin tube 7 is opened, and the lower end of the thin tube 7 bends 90° and extends a part to the constant pressure water tank. 2. At the exit, the top of the thin tube 7 is provided with a slender needle, which extends into the trumpet-shaped interface on the left side of the test tube 9. There is a pulse injector 8 at the end of the thin tube 7, which is used to generate continuous and stable injection into the test tube 9. set doses of color water.

The differential pressure gauge 10 is equipped with a corresponding elevation reading ruler-11, which is perpendicular to the test bench 1, and is provided with a data scale, and a reading fine pointer-1101 that can slide up and down is installed in the middle. There will be a difference in liquid level inside, which is the head loss h _f along the way. You only need to slide the thin reading pointer 1101 to the corresponding liquid level to get an accurate reading, which is practical and convenient. The differential pressure gauge 10 is connected by a thin hose and The experimental tube 9 is connected.

Orifice flowmeter 12 is equipped with corresponding elevation reading ruler 2 13, and elevation reading ruler 2 13 is perpendicular to test bench 1, is provided with data scale, and the reading fine pointer 2 1301 that can slide up and down is installed in the middle, orifice flowmeter 12 and Experimental pipe 9 is connected, and this section experimental pipe 9 is provided with the orifice plate 1201 of central opening circular hole, and experiment pipe 9 internal diameters are D, and the diameter of central circular hole of orifice plate 1201 is d, and local gravitational acceleration is g, and after experiment begins, hole There will be a liquid level difference in the two tubes in the middle of the plate flowmeter 12. You only need to slide the reading pointer 2 1301 to the corresponding liquid level to accurately read the liquid level difference Δh, and then according to the principle of the orifice plate flowmeter 12, the flow rate Where μ is the flow coefficient, the cross-sectional area of the experimental tube 9 is A=0.25×Π×D ² , and the corresponding cross-sectional average flow velocity v=Q÷A.

The fine-tuning rotary pointer valve 1403 is installed on the fine-tuning water flow valve 14, which can realize the rotation of 90°. The front 45° on the fine-tuning water flow valve 14 panel is a 5° coarse-tuning area 1401, and the rear 45° is a 1° fine-tuning area 1402. First rotate the fine-tuning pointer valve 1403 to make the fine-tuning water flow valve 14 fully open, and be in the 5° coarse adjustment zone 1401 within the first 45° range. The fine-tuning pointer valve 1403 rotates 5° each time, and be in the 1° fine-tuning zone 1402 within the rear 45° range. The fine-tuning pointer valve 1403 rotates 1° at a time until the fine-tuning valve 14 is closed, and observes the phenomenon in the experimental tube 9 and records the relevant experimental data for each rotation.

The experimental tube 9 is made of glass. Observe the state of the colored water after the experiment starts. When the colored water presents a stable and obvious straight line in the experimental tube 9, it is in a laminar flow pattern. When the colored water vibrates, bends, and has a wave profile, And gradually spread, when the water flow is so disordered that the colored streamline cannot be seen clearly, it is a turbulent flow pattern.

The operation steps of the utility model device are: firstly open the water inlet pipe 20 switch valve 21, start the water pump 19, make the constant pressure water tank 2 full of water and keep the overflow state and measure the corresponding water temperature with a thermometer, then open the fine-tuning water flow valve 14 valve To the maximum, open the color water switch valve 6 after the water flow is stable, observe the phenomenon in the test tube 9, record the readings of the differential pressure gauge 10 and the orifice flowmeter 12, and then turn the fine-tuning rotary pointer valve 1403, the first 45° rotates 5 degrees each time °, the last 45° rotates 1° each time, and after each rotation, after the water flow is stable, it is necessary to observe the phenomenon in the experimental tube 9 and record the readings of the differential pressure meter 10 and the orifice flowmeter 12 until the fine-tuning water flow valve 14 is completely closed. At the end, close the color water switch valve 6, the water pump 19 and the water inlet pipe 20 switch valve 21, open the drain pipe 24 switch valve 25 to discharge the remaining water in the low water tank 16, and finally calculate the section average flow velocity v, head loss h _f and each group The Reynolds number of the data, and finally judge the critical Reynolds number and draw the relationship curve between lgh _f and lgv.

In this new experimental model, there are reading fine pointer 1 1101 and reading fine pointer 2 1301 that can slide up and down between the elevation reading ruler 11 and the elevation reading ruler 2 13. For specific reading, only the reading fine pointer 1 1101 and the reading fine pointer 2 1301 slides to the corresponding liquid level to be able to read accurately, and the fine-tuning water flow valve 14 installed at the rear end of the test tube 9 can be adjusted at the front 45° by turning the fine-tuning rotary pointer valve 1403 when the water flow valve is fully open. Complete the rough adjustment of 5° for each rotation, and complete the fine adjustment of 1° for each rotation in the last 45°, so that different states of turbulent flow and laminar flow can be observed and corresponding enough data can be recorded to improve the effect and accuracy of the experiment. To avoid various errors caused by manual operation when measuring flow, this experimental instrument is equipped with an orifice flowmeter 12, which can accurately obtain the flow in the experimental pipe 9, and by connecting the sump 15 with the drainage system, the low water tank 16 is connected with the water supply system. Connected, avoiding the problem that the mixed water containing colored water can be reused to affect the observation results. This Renault experimental instrument overcomes the problems of large experimental errors and low precision commonly found in previous Renault experimental instruments, and achieves accurate experiments. Greatly facilitate the operation.

The basic principles, main features, working methods and advantages of the present utility model have been shown and described above. Those skilled in the industry should understand that the above-mentioned embodiments do not limit the utility model in any form, and all technical solutions obtained by means of equivalent replacement or equivalent transformation all fall within the protection scope of the utility model. The unexplained parts involved in the utility model are the same as the prior art or are realized by adopting the prior art.

Claims (7)

1. An accurate Reynolds experimental instrument, characterized by: comprising: a test bench (1), a low-level water tank (16) is arranged under the test bench (1), and a constant pressure water tank (2) is arranged at one end above the test bench (1) , the upper water pipe (17) and the lower water pipe (18) are installed between the lower water tank (16) and the constant pressure water tank (2), and the upper water pipe (17) is connected with the sump pump (19) so that the water in the lower water tank (16) Water is pumped into the constant pressure water tank (2), and the water drawn into the constant pressure water tank (2) flows into the experimental tube (9) through the porous partition (4) in the constant pressure water tank (2), while the overflowing water Flow through the large clapboard (3) to the constant pressure water tank (2) on one side of the large clapboard, flow to the downpipe (18) and flow back to the low water tank (16); Use the color water tank (5) of color water, connect a thin tube (7) under the color water tank (5), the water outlet of the constant pressure water tank (2) is connected with the test tube (9), and the test tube (9) is connected with the differential pressure gauge in turn (10) is connected with the orifice flowmeter (12), and the test tube (9) is equipped with a fine-tuning flow valve (14) near the drain, and the end of the test tube (9) is bent downward by 90° and extends a part to form the drain. A sump (15) is placed below the outlet, and the sump (15) discharges mixed water with colored water through the laboratory drainage system. 2. A kind of precise Reynolds experimental instrument according to claim 1, characterized in that: one side of the low water tank (16) is connected to the water inlet pipe (20), and the water inlet pipe (20) is connected to the laboratory water supply system, The water inlet pipe is connected with a switch valve one (21) for controlling closure, and the end of the water inlet pipe is connected with a float valve (22), and the other side of the low-level water tank (16) is connected with an overflow pipe (23), and the overflow pipe is connected to the low-level water tank (16). ) is higher than the water inlet pipe (20), the discharge pipe (24) is equipped with a control closed switch valve two (25), and the overflow pipe (23) and the discharge pipe (24) are all connected to the laboratory drainage system . 3. a kind of accurate Reynolds experimental instrument according to claim 1 is characterized in that: described color water tank (5) is connected with the capillary (7) that has switching valve three (6), capillary ( 7) The lower end is bent by 90° and extends partly to the water outlet of the constant pressure water tank (2). The extended end is connected with a slender needle, and the slender needle extends into the trumpet-shaped interface of the experimental tube (9). The lower end of the thin tube is also A pulse injector (8) is attached. 4. a kind of accurate Reynolds experiment instrument according to claim 1 is characterized in that: described differential pressure gauge (10) is equipped with corresponding elevation reading ruler one (11), and elevation reading ruler one (11) and The test bench (1) is vertical, provided with a data scale, and a thin reading pointer (1101) that can slide up and down is installed in the middle, and the differential pressure gauge (10) is connected with the test tube (9) through a thin hose. 5. a kind of accurate Reynolds experimental instrument according to claim 1 is characterized in that: described orifice plate flow meter (12) is equipped with corresponding elevation reading ruler two (13), and elevation reading ruler two (13) and The test bench (1) is vertical, equipped with a data scale, and a thin reading pointer 2 (1301) that can slide up and down is installed in the middle. The orifice flowmeter (12) is connected with the test tube (9). There is an orifice plate (1201) with a central round hole, the orifice expands from front to back, and the sides form an angle of 45° with the pipe axis. 6. A kind of precise Reynolds experimental instrument according to claim 1, characterized in that: the fine-tuning rotary pointer valve (1403) is installed on the fine-tuning water flow valve (14), which can rotate 90°. 7. A kind of accurate Reynolds experimental apparatus according to claim 1, is characterized in that: described experimental tube (9) is glass material.