CN101673484B - Self-circulating electrical-testing total hydrostatic pressure tester - Google Patents

Abstract

The invention discloses a self-circulating electrical-testing total hydrostatic pressure tester which is provided with a lower water tank and a water pump arranged in the lower water tank, wherein the lower water tank and an upper water tank are connected by a water supply pipe, a water drain valve is arranged at the bottom of the upper water tank, a support seat is arranged at the upper part of the upper water tank, a lever and the support seat are connected to a fulcrum, a sector body is fixed at the lower end of one side of the lever and extends into the upper water tank, a lever adjusting screw is arranged at the other side of the lever and connected with a ballasting body by a weight hanging rope, and the ballasting body is positioned on a force sensor; and an axial level bubble and a staff gauge are arranged on the sector body. The tester adopts an independent self-circulating constant-pressure water supply system, and is simple, convenient and intuitional in operation; the measurement of the total hydrostatic pressure by using the force sensor is creative initially and is accurate and intuitional; the lever fulcrum and the axial level bubble which are specially arranged eliminate dual influences from external force and force body deformation; the force arm length is accurate; and data is more accurate and reliable.

Description

Self-circulating electrical-testing total hydrostatic pressure tester

Technical field

The present invention relates to the experimental measurement instrument, relate in particular to a kind of self-circulating electrical-testing total hydrostatic pressure tester.

Background technology

Hydraulic structure usually all directly contacts with water body, so the hydrostatic force of calculating on a certain compression face is the practical problems that often runs into.Therefore, the experiment of hydrostatic general pressure is hydraulics and requisite experimental project of hydrodynamics teaching experiment link.

At present, the mode of similar experimental apparatus measurement hydrostatic general pressure both domestic and external adopts manual work to join the method for power more.Yet the total hydrostatic pressure tester of this quasi-tradition exists certain drawback: one of which, and segment disappearance level causes the segment rectangular surfaces vertically to be difficult to calibration to the adjustment reference point, causes experimental implementation loaded down with trivial details, time-consuming; Its two, inter-agency displacement causes experimental error to eliminate; Its three, only depend on manual work to join power, the subject is subjective, and to influence factor bigger, influences experimental precision.

Summary of the invention

The objective of the invention is to overcome the deficiency of prior art, a kind of self-circulating electrical-testing total hydrostatic pressure tester is provided.

Self-circulating electrical-testing total hydrostatic pressure tester has lower header, in lower header, is provided with water pump, and lower header is connected through feed pipe with upper water box, and the upper water box bottom is provided with water drain valve; Upper water box top is provided with bearing, and lever and bearing are connected in fulcrum, lever one side lower end fixed fan body; Segment probes in the upper water box; The lever opposite side is arranged the lever adjusting screw, and the lever adjusting screw is hung heavy line with the ballast body and function and is connected, and the ballast body places on the force cell.

Have axial air level, scale on the described segment, axially during the air level reveal competence, the segment rectangular surfaces is a vertical guide, and segment two arcwall faces are concentric circles, and the center of circle intersects at fulcrum.Described upper water box inner width must be than more than the big 2cm of segment thickness, and segment places the upper water box center.

The present invention compared with prior art, the beneficial effect that has:

1) adopted independent self-loopa constant pressure water supply system, easy and simple to handle directly perceived, be suitable for the modern teaching requirement;

2) the initiative force transducer is surveyed the hydrostatic general pressure, and is accurately directly perceived;

3) axial level reference of balance pivot and segment and instruction device are set specially, eliminate external force and beaer displacement double influence, arm of force length is accurate, and data are more accurately reliable.

Description of drawings:

Fig. 1 is a self-circulating electrical-testing experiment instrument hydrostatic general pressure structural representation;

Fig. 2 is the hydrostatic general pressure on the arbitrary plane;

Fig. 3 is the hydrostatic general pressure on the rectangle plane;

Fig. 4 is the hydrostatic general pressure on the vertical plane.

Among the figure: lever 1, axially air level 2, segment 3, bearing 4, fulcrum 5, lever adjusting screw 6, scale 7, upper water box 8, feed pipe 9, water drain valve 10, lower header 11, water pump 12, hang heavy line 13, ballast body 14, force cell 15

Embodiment

As shown in Figure 1, self-circulating electrical-testing total hydrostatic pressure tester has lower header 11, in lower header 11, is provided with water pump 12, and lower header 11 is connected through feed pipe 9 with upper water box 8; Upper water box 8 bottoms are provided with water drain valve 10; Upper water box 8 tops are provided with bearing 4, and lever 1 is connected in fulcrum 5, lever 1 one side lower end fixed fan bodies 3 with bearing 4; Segment 3 probes in the upper water box 8; Lever 1 opposite side is arranged lever adjusting screw 6, and lever adjusting screw 6 is hung heavy line 13 with ballast body 14 usefulness and is connected, and ballast body 14 places on the force cell 15.

Have axial air level 2, scale 7 on the described segment 3, axially during air level 2 reveal competences, segment 3 rectangular surfaces are vertical guide, and 3 liang of arcwall faces of segment are concentric circles, and the center of circle intersects at fulcrum 5.

Described upper water box 8 inner widths must be than more than the big 2cm of segment 3 thickness, and segment 3 places upper water box 8 centers.

The course of work of the present invention is: start water pump in the lower header; Lower header supplies water in upper water box, treats that water level reaches a certain position in the upper water box, switches off the pump; The partial volume that probes into the segment in the upper water box is immersed in the water; Its level is recorded by the force cell induction to the moment of hydrostatic force to the fulcrum generation, and experiment finishes, and opens water drain valve and can make the interior water body of upper water box get back to lower header.

Experimental provision of the present invention, its principle of work, its equation is:

1. inactive liquid acts on the general pressure on the arbitrary plane

The hydrostatic general pressure is found the solution, and comprises size, direction and application point.MN is the projection line that forms a tilting arbitrary plane at θ angle with surface level among Fig. 2.The effect of water is born on the right side, and the compression face area is A.C represents the centre of form on pressurized plane, and F represents hydrostatic general pressure on the plane, and D represents the application point of hydrostatic general pressure.

Act on arbitrary orientation, the size of the hydrostatic general pressure F on the arbitrary shape plane equals the product of compression face area and the suffered hydrostatic pressure of its centroid point C, promptly

F＝∫ _AdF＝p _c·A

The direction of general pressure is the inter normal direction along compression face.

2. the hydrostatic general pressure on the rectangle plane

If a rectangle plane tilts to place water, like Fig. 3.Dried up the height in rectangle plane top is h, and the end is dried up, and a height is H, and the rectangle width is b, highly is a.

(1) general pressure size F does

$F=\frac{1}{2}\mathrm{\ρg}(h+H)\mathrm{ab}$

Point of resultant force apart from the end apart from e does

$e=\frac{a}{3}\·\frac{2h+H}{h+H}$

(2) if pressure is triangle to distribute, h=0 then, the general pressure size does

$F=\frac{1}{2}\mathrm{\ρgHab}$

Point of resultant force apart from the distance at the end does

$e=\frac{a}{3}$

(3) if acting surface is a vertical to be placed,, can make like Fig. 4

$h=\left\{\begin{array}{cc}0& (H<a)\\ H-a& (H\&GreaterEqual;a)\end{array}\right.$

Be that pressure is that trapezoidal profile or triangle distribute, its general pressure size all can be expressed as

$F=\frac{1}{2}\mathrm{\&rho;g}(H^2-h^2)b$

Distance also all can be expressed as point of resultant force the end of apart from

$e=\frac{H-\mathrm{<figure-callout\; id="3"\; label="h"\; filenames="H2009101536477E00011.png"\; state="\{\{state\}\}">h</figure-callout>}}{3}\&CenterDot;\frac{2h+H}{h+H}$

Data processing and achievement requirement

1. record reaches experimental constant for information about

The experimental facilities title: Electrical measurement plane total hydrostatic pressure testerExperiment table number: 1

The experimenter: _ _ _ _ the experiment date: _ _ _ _

Lever arm distance L ₀= 22.5* 10 ^-2M segment vertical range (fan-shaped radius) L= 25* 10 ^-2m

The wide b=of segment 8* 10 ^-2The high a=of m rectangle end face 9.8* 10 ^-2m

ρ＝1.0×10 ³kg/m ³

2. EDR (ginseng table 1) and result of calculation (ginseng table 2)

Table 1 survey record form

Table 2 experimental result form

3. achievement requirement

Can be known that by table 2 result experiment value and theoretical value compare, maximum error is no more than 2%, has verified the correctness of the plane hydrostatic general pressure theory of computation.

Analysis and thinking

May well ask which darker place under liquid level, Center of Pressure of the Center of Pressure that acts on absolute pressure on the liquid level lower plane figure and pressure relatively? Why?

Answer: the Center of Pressure that acts on relative pressure on the liquid level lower plane figure is darker under liquid level than the Center of Pressure of absolute pressure.

Because absolute pressure increases an equally distributed atmospheric effect than relative pressure, the figure of pressure distributions on the plane more is in evenly, and pressure distributions is even more on the plane, the Center of Pressure is just the closer to the centre of form on plane.Centre of form place is the most shallow degree of depth of the limit that the Center of Pressure possibly reach.

Claims (3)

1. a self-circulating electrical-testing total hydrostatic pressure tester is characterized in that it has lower header (11), in lower header (11), is provided with water pump (12), and lower header (11) is connected through feed pipe (9) with upper water box (8); Upper water box (8) bottom is provided with water drain valve (10); Upper water box (8) top is provided with bearing (4), and lever (1) is connected in fulcrum (5), lever (1) one side lower end fixed fan body (3) with bearing (4); Segment (3) probes in the upper water box (8); Lever (1) opposite side is arranged lever adjusting screw (6), and lever adjusting screw (6) is connected with hanging heavy line (13) with ballast body (14), and ballast body (14) places on the force cell (15).

2. a kind of self-circulating electrical-testing total hydrostatic pressure tester according to claim 1; It is characterized in that; Have axial air level (2), scale (7) on the described segment (3), axially during air level (2) reveal competence, the rectangular surfaces that segment (3) probes in the water is a vertical guide; Segment (3) two arcwall faces are concentric circles, and the center of circle intersects at fulcrum (5).

3. a kind of self-circulating electrical-testing total hydrostatic pressure tester according to claim 1 is characterized in that, described upper water box (8) inner width must be than more than the big 2cm of segment (3) thickness, and segment (3) places upper water box (8) center.

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