CN104697742A - Simulation test model device for studying hyporheic exchange under drive of flood pulse and using method thereof - Google Patents

Abstract

The invention discloses a simulated test model device for studying subsurface flow exchange driven by flood pulses and a use method thereof, comprising a water tank body, an upstream surface water supply system, a groundwater control box and a flood pulse drive device. The water tank body is provided with a partition that can divide the water tank body into a water level control room and a drainage room, and a river flood beach model is arranged in the water level control room. Subsurface exchange is possible between the groundwater control box and the floodplain model. The flood pulse driving device includes a lifting piston that can move up and down in the partition and a periodic waveform driving device. The lifting piston can be lifted and lowered periodically under the drive of the periodic waveform drive device, so that the flood peak process line in the water level control chamber changes periodically. After adopting the above-mentioned structure and method, the surface water level in the upstream is driven by periodic flood pulses to periodically change in proportion to a specific flood peak process line, while the groundwater level in the downstream remains constant, which is close to the exchange of subsurface flow in natural floodplains.

Description

A simulation test model device and its application method for studying subsurface flow exchange driven by flood pulse

technical field

The invention relates to a test device and its use method, in particular to a simulation test model device and its use method for studying the exchange of subsurface flow driven by flood pulses.

Background technique

Subsurface exchange is a dynamic process in which surface water and groundwater exchange and mix in rivers and their coastal zones, and plays a very important role in regulating river ecology and landscape heterogeneity.

Generally speaking, the seasonal flood process will change the hydrological pattern of the river area, and then affect the subsurface exchange process between the main channel of the river and its floodplain system. This problem is further complicated by the complex flow structure in the subsurface exchange zone and the two different time scales involved in the movement of surface water and groundwater.

At present, it is a common method used by scholars at home and abroad to study the related issues of subsurface exchange by using the indoor tank test method. The literature survey shows that in the past, most researchers simulated river channels by establishing physical models of indoor water tanks, filled the water tanks with sand and pebbles of different particle sizes, and constructed structures of the required shape to form riverbed structures, and provided the water tanks with the water needed for experiments through water circulation equipment. Circulating water, through the water tank and flow valve to control the surface water and groundwater flow conditions required for the test, and arrange relevant acquisition instruments and various sensors to measure the required data such as various water flow parameters, temperature, and river bed interface pressure intensity.

However, the above-mentioned indoor flume models usually focus on the subsurface flow exchange process under the influence of bed topography, river plane form, or obstacles (such as sand waves, steps, deep pools, shoals, gravel, wood, bends, etc.), Its most intuitive characteristic of water flow is that the river bed is completely covered by water flow. The main driving force of subsurface flow exchange comes from the unbalanced pressure near the bed surface. The focus of attention is the influence of bed surface structure on vertical subsurface flow exchange. The limitation is that it cannot It is used to study the influence of the side-beach dry-wet alternation process caused by the rapid change of water level on the lateral subsurface flow exchange in the main channel-beach system of the river.

Contents of the invention

The technical problem to be solved in the present invention is to aim at the deficiencies of the above-mentioned prior art, and provide a kind of simulation test model device and its use method for studying the subsurface flow exchange driven by flood pulse. The simulation test model and its use method can break the The traditional integrated model of circulating water in the upstream and downstream tanks makes the upstream surface water level change periodically in proportion to a specific flood peak process line driven by periodic flood pulses, while the downstream groundwater level remains constant.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A simulation test model device for studying subsurface flow exchange driven by flood pulses, including a tank body, an upstream surface water recharge system and a downstream groundwater control system, and a flood pulse drive device, wherein:

A dividing plate is arranged in the water tank body, and the dividing plate divides the water tank body into a water level control room and a drainage room, and a river flood beach model is arranged in the water level control room.

A vertical vertical chute is provided in the partition, and the vertical chute includes a first vertical slot at the bottom and a second vertical slot at the top; the partitions at both sides of the second vertical slot Each plate is provided with a through groove, and the two through grooves can communicate the second vertical groove with the water level control chamber and the drain chamber.

The upstream surface water replenishment system includes a replenishment water tank, wherein the water inlet of the replenishment water tank is connected to the bottom of the water level control chamber, and the water outlet of the replenishment water tank is connected to the discharge chamber.

The downstream groundwater control system includes a groundwater control box arranged on one side of the tank body, the water level in the groundwater control box can be kept constant, and subsurface exchange can be performed between the groundwater control box and the floodplain model.

The flood pulse driving device includes a lifting piston arranged in a vertical chute and a periodic waveform driving device.

The outer surface of the lifting piston can seal fit with the inner surface of the vertical chute, the height of the lifting piston is equal to the height of the first vertical groove, and the top of the lifting piston extends from the water level control chamber to the water discharge guide of the water discharge chamber. groove.

The top of the lifting piston is connected with the periodic waveform driving device, and the lifting piston can be periodically raised and lowered under the driving of the periodic waveform driving device, so that the flood peak process line in the water level control chamber changes periodically.

The periodic waveform driving device is a sinusoidal waveform driving device, and the lifting piston can be periodically raised and lowered under the driving of the sinusoidal waveform driving device, so that the flood peak process line in the water level control chamber is a sinusoidal waveform.

The sine wave driving device includes a bull gear and a pinion that are fixedly arranged above the water tank body and mesh with each other, the pinion is connected with the motor, and a short connecting rod arranged in the radial direction of the bull gear is fixedly connected to the center point of the bull gear. The other end of the short connecting rod is hinged with a long connecting rod, and the other end of the long connecting rod is provided with a connecting piece connected with the top of the lifting piston.

A manual piston is arranged in the groundwater control box, and the constant water level in the groundwater control box can be adjusted by controlling the height of the manual piston.

The top of the flooded flat model is arranged obliquely, and the height of the flooded flat model facing the side of the dividing plate is the lowest.

A method for using a simulated test model device for studying flood pulse-driven subsurface flow exchange, comprising the following steps:

The first step is groundwater level control: by adjusting the supply water source of the groundwater control box, the groundwater level in the groundwater control box is kept constant;

The second step, surface water supply in the water level control chamber: supply surface water to the water level control chamber through the water inlet of the supply water tank in the upstream surface water supply system; at this time, the lifting piston is located at the bottom of the first vertical groove, and the height of the lifting piston is is the initial water level in the water level control chamber;

The third step, the lifting piston rises: driven by the sine wave drive device, the lifting piston rises, and the flood peak in the water level control room is discharged into the water discharge room through the drainage guide groove on the top of the lifting piston, so that the flood peak process line in the water level control room Change from the lowest water head to the highest water head in a sine wave curve;

In the fourth step, the flood peak process line in the water level control room reaches the highest water head: the lifting piston continues to rise, and when the sine wave drive device drives the lifting piston to rise to the highest point, the flood peak process line in the water level control room reaches the highest water head; the lifting piston rises to the maximum The height is less than the height of the lifting piston;

In the fifth step, the lifting piston descends. Driven by the sinusoidal waveform driving device, the lifting piston descends, and the flood peak process line in the water level control chamber changes from the highest water head to the lowest water head in a sinusoidal waveform curve;

In the sixth step, the flood peak process line in the water level control room returns to the initial water level: the lifting piston continues to descend, and when the sine wave drive device drives the lifting piston down to the lowest point, the flood peak process line in the water level control room returns to the initial water level;

The seventh step, repeat the third step to the sixth step: the lifting piston is lifted and lowered periodically, so that the flood peak process line in the water level control room presents a sinusoidal waveform curve;

The eighth step is to calculate the subsurface exchange between surface water and groundwater.

In the second step, the flow rate of the water source at the water inlet of the replenishment water tank in the upstream surface water replenishment system is:

$\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; ></span>\frac{\mathrm{<span\; class="notranslate">\; H\&pi;LS</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}$

In the formula, Q is the water source flow rate of the water inlet of the supply tank, T is the period of the flood peak process line in the water level control room, H is the highest water head of the flood peak process line in the water level control room, L is the length of the tank body, and S is the width of the tank body.

In the fourth step, the calculation method of the highest water head of the flood peak process line in the water level control room is as follows:

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\sqrt{{\mathrm{<span\; class="notranslate">\; b</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; )</span>$

In the formula, H is the highest water head of the flood peak process line in the water level control chamber, _h1 is the height of the lifting piston, a is the length of the short connecting rod, and b is the length of the long connecting rod.

The calculation formula of the motor speed in the sine wave drive device is:

$\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; R</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Tr</span>}}$

In the formula, n is the motor speed, R is the radius of the large gear, r is the radius of the pinion, and T is the period of the flood peak process line in the water level control room.

In the eighth step, the subsurface exchange volume between the surface water and the groundwater, that is, the subsurface exchange volume between the groundwater control box and the flood beach model, is: Q _submerged =Q _out -Q _in

In the formula, Q _potential is the subsurface flow exchange between surface water and groundwater, Q _out represents the outflow of groundwater outlet in the groundwater control box, and Q _in represents the inflow of recharge water source in the ground water control box, when Q _potential is a positive value It indicates that the surface water excretes to the groundwater, and the negative value of Q _potential indicates that the groundwater recharges the surface water.

After the present invention adopts the above-mentioned structure and using method, it has the following beneficial effects:

1. Changed the production mode of the traditional integrated simulation test model of the upstream and downstream water cycle, so that the upstream surface water and the downstream low water have independent control systems.

2. The setting of the above-mentioned flood pulse driving device enables the water level in the tank body to be adjusted proportionally according to the specific flood peak process line, so as to realize the flood pulse driving effect in the water level control room.

3. The periodic change of the surface water level in the upper reaches will carry out the non-submerged-partially submerged-full submerged-partially submerged-non-submerged cyclic subsurface flow exchange process for the floodplain model, which is very close to the subsurface flow exchange in the natural floodplain.

4. The periodic waveform driving device can also be a triangular wave driving device, so that the effects of different water flow waveforms on subsurface exchange can be compared on the basis of sinusoidal waveforms.

5. The above-mentioned groundwater control box can maintain a constant water level, and at the same time, it can adjust the constant underground water level through a manual piston to simulate two situations of surface water discharge and groundwater replenishment.

6. Generally, the subsurface exchange test cannot directly calculate the subsurface exchange volume, but can only obtain the relative intensity of the subsurface exchange. However, this device can calculate the subsurface exchange volume corresponding to each moment according to the relevant monitoring data, and form a periodic change curve of the subsurface exchange volume. , which provides an important basis for the study of flood pulse subsurface flow exchange mechanism.

Description of drawings

Fig. 1 has shown a kind of structural representation of the simulated test model device of the present invention being used to study the simulation test model device of subsurface flow exchange driven by flood pulse;

Fig. 2 has shown the position figure of lifting piston and sinusoidal wave driving device in the initial moment among the present invention;

Fig. 3 has shown the position diagram of lifting piston and sine wave driving device in the middle of a certain moment in the present invention;

Fig. 4 has shown the position figure of lifting piston and sinusoidal wave driving device in the highest water head in the present invention;

Fig. 5 has shown the position figure of lifting piston and sinusoidal wave driving device in the last moment among the present invention;

Figure 6 shows an enlarged schematic view of the separator in Figure 1 .

Among them are: 10. Tank body; 11. Water level control room; 111. River flood beach model; 112. Nylon geotextile; 113. Initial water level; 211. The first vertical tank; 212. The second vertical tank; 22. The through tank; 30. The upstream surface water supply system; 31. The supply water tank; 32. The supply water tank inlet; 33. The supply water tank outlet; 34. Flow meter; 35. Circulating water pump; 40. Downstream groundwater control system; 41. Groundwater control box; 42. Supply water source; 43. Groundwater outlet; 50. Sine wave drive device; 51. Lifting piston; 511. Drainage guide groove ; 512. Iron wire; 52. Small gear; 521. Iron stand; 53. Big gear; 531. Center point; 532. Short connecting rod;

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

As shown in FIG. 1 , a simulated test model device for studying subsurface flow exchange driven by flood pulses includes a tank body 10 , an upstream surface water replenishment system 30 , a downstream groundwater control system 40 and a flood pulse drive device.

The length, width and height of the tank body 10 are 2m, 0.15m and 1m respectively. Here, the width of the water tank body 10 is designed to be narrow for the following two reasons: one is to better simulate the two-dimensional subsurface flow exchange, and the other is to facilitate the effective adjustment of the upstream surface water level.

A partition 20 is arranged in the tank body 10, and the partition board 20 divides the tank body 10 into a water level control chamber 11 and a drain chamber 12.

The water level control room 11 is provided with a river flooding flat model 111, and the top of the river flooding flat model 111 is inclined, and the slope is preferably 0.143. As shown in Fig. 1, the height of the flooded flat model 111 (that is, the left side of the river flooded model 111) towards the side of the dividing plate 20 is the lowest, preferably 0.6m, then the height of the right side of the flooded flat model 111 is preferably 0.8m, the upstream and downstream lengths are preferably 1.4m. The left side of the floodplain model 111 is preferably provided with a nylon geotextile 112 to prevent the loss of filler in the floodplain model 111 . The filler of the floodplain model 111 is preferably mixed with clay with a small permeability coefficient and quartz sand. After mixing, the porosity is 0.25 and the dry density is 1.6.

As shown in FIG. 6 , a vertical sliding slot 21 is disposed inside the partition plate 20 , and the vertical sliding slot 21 includes a first vertical slot 211 at the lower part and a second vertical slot 212 at the upper part. The partitions 20 on both sides of the second vertical groove 212 are respectively provided with a through groove 22 , and the two through grooves 22 can communicate the second vertical groove 212 with the water level control chamber 11 and the drain chamber 12 .

The upstream surface water replenishment system 30 includes a replenishment water tank 31 , wherein a water inlet 32 of the replenishment water tank is connected to the bottom of the water level control chamber 11 , and a water outlet 33 of the replenishment water tank is connected to the drain chamber 12 . A flow meter 34 and a circulating water pump 35 are also arranged on the pipeline where the water outlet 33 of the makeup water tank is located. The upstream surface water replenishment system 30 forms an upstream surface water circulation system as a whole, continuously supplies water to the water level control chamber 11, and the replenishment flow rate must be large enough during the rise of the water level, which must be greater than the volume of the water tank body increased by 10 units of time. When the water level drops, the upstream surface water replenishment system 30 need not work.

The downstream groundwater control system 40 includes a groundwater control box 41 arranged on one side of the tank body 10, and the groundwater control box 41 is preferably made of plexiglass. The water level in the groundwater control box 41 can be kept constant, and the subsurface flow can be exchanged between the groundwater control box 41 and the floodplain model 111 .

The optimal mode for subsurface flow exchange between the groundwater control box 41 and the flooded beach model 111 is as follows: the left side of the groundwater control box 41 is connected with the flooded beach model 111, separated by a nylon geotextile 112 in the middle, and only water is allowed to pass through. The right side of the groundwater control box 41 is provided with a supply water source 42 and a groundwater outlet 43 .

A manual piston is preferably provided at the ground water outlet 43, and by adjusting the manual piston 11, the initial constant ground water level in the ground water control box 41 is adjusted to meet different test conditions. In addition, a measuring cylinder is also provided at the groundwater outlet 43, which can be used to receive the amount of water flowing out.

The method for keeping the water level in the groundwater control box 41 constant is: when the groundwater is replenished by the groundwater, excess water flows out from the groundwater outlet 43, and the groundwater remains constant; , it is necessary to continuously supply the required water source to the underground water tank from the replenishment water source 42, so as to keep the groundwater constant.

The flood pulse driving device includes a lifting piston 51 arranged in the vertical chute 21 and a periodic waveform driving device.

The outer surface of the lifting piston 51 can seal fit with the inner surface of the vertical chute 21 , for example, sealing materials such as water stop strips are filled between the lifting piston 51 and the vertical chute 21 .

The height of the lift piston 51 is equal to the height of the first vertical groove 211 , and the top of the lift piston 51 extends from the water level control chamber 11 to the drain guide groove 511 of the drain chamber 12 . In this way, the height of the lifting piston 51 is also the initial water level 113 in the water level control chamber 11 . When the lifting piston 51 rises, the lifting piston 51 can partially block the through grooves 22 on both sides of the second vertical groove 212, and guide the flood peak at the top of the water level control chamber 11 to quickly flow out of the water discharge guide groove 511, so that the water level control chamber The flood peak process line in 11 changes periodically.

The top of the lifting piston 51 is connected with the periodic waveform driving device, and the lifting piston 51 can be periodically raised and lowered under the driving of the periodic waveform driving device, so that the flood peak process line in the water level control chamber 11 presents periodic changes.

The above-mentioned periodic waveform driving device is preferably a sinusoidal waveform driving device 50, but may also be a triangular waveform. The lifting piston 51 can be lifted and lowered periodically under the drive of the sinusoidal waveform driving device 50, so that the flood peak process line in the water level control chamber 11 is a sinusoidal waveform.

The sine wave driving device 50 includes a large gear 53 and a pinion 52 fixedly arranged above the water tank body 10 and meshing with each other. The pinion 52 is connected with a motor, preferably a stepping motor, as a driving wheel. The bull gear 53, the pinion 52 and the motor are all preferably fixed on the iron frame platform 521.

The central point 531 of the bull gear 53 is fixedly connected with a short connecting rod 532 arranged radially along the bull gear 53, the other end of the short connecting rod 532 is hinged with a long connecting rod 533, and the other end of the long connecting rod 533 is provided with a Roots are connected with the top of the lifting piston 51. The connecting member is preferably an iron wire 512, but may also be other connecting parts with better hardness such as steel wire and copper wire.

The model device of the present application can calculate the corresponding subsurface flow exchange volume at each moment according to the relevant monitoring data, and form a periodic change curve of the subsurface flow exchange volume, which provides an important basis for the research on the mechanism of flood pulse subsurface flow exchange.

A method for using a simulated test model device for studying flood pulse-driven subsurface flow exchange, comprising the following steps:

The first step is groundwater level control: by adjusting the supply water source of the groundwater control box, the groundwater level in the groundwater control box is kept constant.

The second step, surface water replenishment in the water level control chamber: supply surface water to the water level control chamber through the water inlet of the replenishment water tank in the upstream surface water replenishment system; as shown in Figure 2, at this time, the lifting piston is located At the bottom, the height of the lifting piston is the initial water level in the water level control chamber.

The third step, the lifting piston rises: as shown in Figure 3, driven by the sine wave drive device, the lifting piston rises, and the flood peak in the water level control room is discharged into the water discharge chamber through the drainage guide groove on the top of the lifting piston, so that the water level The flood peak process line in the control room changes from the lowest water head to the highest water head in a sinusoidal waveform curve.

The fourth step, the flood peak process line in the water level control room reaches the highest water head: the lifting piston continues to rise, when the sine wave drive device drives the lifting piston to rise to the highest point, as shown in Figure 4, the flood peak process line in the water level control room reaches the highest water head ; The maximum height that the lifting piston rises is less than the height of the lifting piston.

In the fifth step, the lifting piston descends. Driven by the sinusoidal waveform driving device, the lifting piston descends, and the flood peak process line in the water level control chamber changes from the highest water head to the lowest water head in a sinusoidal waveform curve.

In the sixth step, the flood peak process line in the water level control room returns to the initial water level: as shown in Figure 5, the lifting piston continues to descend, and when the sine wave drive device drives the lifting piston down to the lowest point, the flood peak process line in the water level control room returns to initial water level.

The seventh step is to repeat the third step to the sixth step: the lifting piston is lifted and lowered periodically, so that the flood peak process line in the water level control chamber presents a sinusoidal waveform curve.

The eighth step is to calculate the subsurface exchange between surface water and groundwater.

In the steps above, the full cycle of the test run is shown. Among them, in the first half cycle of the test operation, the water level continued to rise according to a sinusoidal curve, gradually submerging the floodplain, and the intensity and range of subsurface exchange increased accordingly; During the whole test period, the water level changes proportionally according to the specific flood process line, and the intensity and range of subsurface exchange change accordingly. The main driving force is the fluctuation of water level, that is, the flood pulse.

The trend of the flood peak process line in the water level control chamber 11 is close to a sinusoidal curve, therefore, the surface water level is adjusted according to the sinusoidal curve in the following formula.

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; h</span>}\mathrm{<span\; class="notranslate">\; sin</span>}\frac{\mathrm{<span\; class="notranslate">\; \&pi;t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}$

In the formula, h is the water head that the surface water level rises and falls with time t; H is the highest water head of the flood peak process line in the water level control room.

Deriving the above sinusoidal curve, the surface water level rise and fall rate curve is:

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; H\&pi;</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}\frac{\mathrm{<span\; class="notranslate">\; \&pi;t</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}$

In the half cycle of water level rise, the initial time t=0 is the fastest time of water level rise rate, and the corresponding rate is:

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; H\&pi;</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}$

Then the fastest volume increase per unit time of the water level control room 11 is approximately:

$\frac{\mathrm{<span\; class="notranslate">\; H\&pi;LS</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}$

In order to make the water level in the water level control chamber 11 change synchronously with the lifting piston 51, the flow rate of the water source at the water inlet of the replenishment water tank in the upstream surface water replenishment system is:

$\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; ></span>\frac{\mathrm{<span\; class="notranslate">\; H\&pi;LS</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}$

In the formula, Q is the water source flow rate of the water inlet of the supply tank, T is the period of the flood peak process line in the water level control room, H is the highest water head of the flood peak process line in the water level control room, L is the length of the tank body, and S is the width of the tank body.

The analysis shows that the smaller the tank body size and flood peak head, the larger the flood cycle and recharge flow, and the easier to coordinate the water level rise and fall of the entire system.

In addition, by designing the heights of the short connecting rod 532, the long connecting rod 533 and the lifting piston 51, the highest water head of the flood peak process line in the water level control chamber can be adjusted. It can be seen from this device that the maximum water head of the flood peak process line is less than

As shown in FIG. 2 , at the initial moment, the bottom of the lifting piston 51 is flush with the bottom of the tank body 10 , and the height _h1 of the lifting piston 51 is also the initial water level. At this time, the distance between the center point of the large gear and the lower end point of the long connecting rod is assumed to be S ₁ , then When the lifting piston rises to the highest point, as shown in Figure 4, the long connecting rod and the short connecting rod are in a straight line, and the lower end of the long connecting rod moves upward for a distance of _S2 , the maximum distance that the lifting piston rises is Therefore, the maximum water head of the flood peak process line in the water level control chamber is the sum of the initial water level and the maximum distance of the lifting piston, that is, the calculation method is as follows:

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>\sqrt{{\mathrm{<span\; class="notranslate">\; b</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}<span\; class="notranslate">\; )</span>$

In the formula, H is the highest water head of the flood peak process line in the water level control chamber, _h1 is the height of the lifting piston, a is the length of the short connecting rod, and b is the length of the long connecting rod. In addition, the maximum distance that the lifting piston rises is smaller than the height of the lifting piston, that is, the bottom of the lifting piston is always in the first vertical groove 211 .

As shown in Fig. 2, Fig. 3, Fig. 4 and Fig. 5, the rotation of the bull gear 53 for half a circle is a flood cycle, which corresponds to the lift piston 51 lifting back and forth. According to a specific flood cycle, the formula for calculating the motor speed can be calculated as:

$\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; R</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Tr</span>}}$

In the formula, n is the motor speed, R is the radius of the large gear, r is the radius of the pinion, and T is the period of the flood peak process line in the water level control room.

The subsurface exchange volume between surface water and groundwater, that is, the subsurface exchange volume between the groundwater control box 41 and the floodplain model 111, in order to facilitate the calculation of the subsurface exchange volume, the water inlet will always be supplied with a constant flow of water. The calculation formula for:

Q _potential = Q _out - Q _into

In the formula, Q _potential is the subsurface flow exchange between surface water and groundwater, Q _out represents the outflow of groundwater outlet in the groundwater control box, and Q _in represents the inflow of recharge water source in the ground water control box, when Q _potential is a positive value It indicates that the surface water excretes to the groundwater, and the negative value of Q _potential indicates that the groundwater recharges the surface water.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (10)

1., for studying the simulation test model equipment that flood pulsed drive subsurface flow exchanges, comprising water trough body, upstream surface water supply system and downstream descending water control system, it is characterized in that: also comprising flood pulse driving device, wherein:

---be provided with one piece of dividing plate in described water trough body, water trough body is partitioned into water lev el control room and sluicing room by this dividing plate, and water lev el control indoor are provided with leaching beach, river model;

---be provided with a vertical vertical chute in described dividing plate, this vertical chute comprises the first vertical slot and superposed second vertical slot that are positioned at bottom; The dividing plate being positioned at the second vertical slot both sides is respectively provided with a through slot, and the second vertical slot can be connected with sluicing room with water lev el control room by two through slots;

---described upstream surface water supply system comprises an extra feed tank, and wherein, extra feed tank water inlet is connected with bottom water lev el control room, and extra feed tank water delivering orifice is connected with sluicing room;

---described downstream descend water control system to comprise Groundwater Control case that one is arranged at water trough body side, the water level in this Groundwater Control case can keep constant, and can carry out undercurrent exchange between Groundwater Control case and leaching beach, river model;

---described flood pulse driving device comprises and is arranged on lifting piston in vertical chute and periodic waveform drive unit;

---the outside surface of described lifting piston can be sealed and matched with the inside surface of vertical chute, and the height of lifting piston is equal with the height of the first vertical slot, and the top of lifting piston is provided with the sluicing gathering sill stretching to sluicing room from water lev el control room;

---the top of lifting piston is connected with periodic waveform drive unit, and lifting piston periodically can be elevated under the driving of periodic waveform drive unit, the flood peak graph of water lev el control indoor is presented and periodically changes.

2. according to claim 1 for studying the simulation test model equipment that flood pulsed drive subsurface flow exchanges, it is characterized in that: described periodic waveform drive unit is sinusoidal waveform drive unit, lifting piston periodically can be elevated under the driving of sinusoidal waveform drive unit, makes the flood peak graph of water lev el control indoor be sinusoidal waveform.

3. according to claim 2 for studying the simulation test model equipment that flood pulsed drive subsurface flow exchanges, it is characterized in that: described sinusoidal waveform drive unit comprises and to be all fixedly installed on above water trough body and intermeshing gear wheel and pinion wheel, pinion wheel is connected with motor, the central point of gear wheel is fixedly connected with a short connecting rod arranged along gear wheel radial direction, the other end of this short connecting rod is hinged with a long connecting rod, and the other end of long connecting rod is provided with a web member be connected with lifting piston top.

4. according to claim 1 for studying the simulation test model equipment that flood pulsed drive subsurface flow exchanges, it is characterized in that: in described Groundwater Control case, be provided with hand piston, by controlling the height of hand piston, the constant water level in Groundwater Control case can be adjusted.

5. according to claim 1 for studying the simulation test model equipment that flood pulsed drive subsurface flow exchanges, it is characterized in that: the top droop of leaching beach, described river model is arranged, and the height towards leaching beach, the river model of dividing plate side is minimum.

6., for studying a using method for the simulation test model equipment that flood pulsed drive subsurface flow exchanges, it is characterized in that: comprise the following steps:

The first step, groundwater level controls: by the nourishment source of adjustment Groundwater Control case, makes the groundwater level in Groundwater Control case keep constant;

Second step, the indoor surface water supply of water lev el control: by the extra feed tank water inlet in upstream surface water supply system, to the indoor supply surface water of water lev el control; Now, lifting piston is positioned at the bottom of the first vertical slot, and the height of lifting piston is the initial water level of water lev el control indoor;

3rd step, lifting piston rises: under the driving of sinusoidal waveform drive unit, lifting piston rises, the flood peak of water lev el control indoor, thus makes the flood peak graph of water lev el control indoor present in sinusoidal waveform profile to change from the lowest water head to most high water head to the indoor discharge of sluicing by the sluicing gathering sill at lifting piston top;

4th step, the flood peak graph of water lev el control indoor reaches most high water head: lifting piston continues to rise, and when sinusoidal waveform drive unit drives lifting piston to rise to peak, the flood peak graph of water lev el control indoor reaches most high water head; The maximum height that lifting piston rises is less than the height of lifting piston;

5th step, lifting piston declines, and under the driving of sinusoidal waveform drive unit, lifting piston declines, and the flood peak graph of water lev el control indoor presents in sinusoidal waveform profile and changes to the lowest water head from most high water head;

6th step, the flood peak graph of water lev el control indoor returns to initial water level: lifting piston continuous decrease, and when sinusoidal waveform drive unit drives lifting piston to drop to minimum point, the flood peak graph of water lev el control indoor returns to initial water level;

7th step, repeats the 3rd step to the 6th step: lifting piston is periodically elevated, and makes the flood peak graph of water lev el control indoor be rendered as sinusoidal waveform profile;

8th step, calculates the undercurrent exchange capacity of surface and ground water.

7. the using method for studying the simulation test model equipment that flood pulsed drive subsurface flow exchanges according to claim 6, it is characterized in that: in described second step, in upstream surface water supply system, the water source flow of extra feed tank water inlet is:

$Q>\frac{\mathrm{H\&pi;LS}}{T}$

In formula, Q is the water source flow of extra feed tank water inlet, and T is the cycle of the indoor flood peak graph of water lev el control, and H is the most high water head of the indoor flood peak graph of water lev el control, and L is the length of water trough body, and S is the width of water trough body.

8. according to claim 7ly it is characterized in that: in described 4th step for studying the using method of simulation test model equipment that flood pulsed drive subsurface flow exchanges, the most high water head computing method of the indoor flood peak graph of water lev el control are as follows:

$H=h_1+\sqrt{b^2-a^2}-(b-a)$

In formula, H is the most high water head of the indoor flood peak graph of water lev el control, h ₁for the height of lifting piston, a is the length of short connecting rod, and b is the length of long connecting rod.

9. the using method for studying the simulation test model equipment that flood pulsed drive subsurface flow exchanges according to claim 6, is characterized in that: in described sinusoidal waveform drive unit, the computing formula of motor speed is:

$n=\frac{R}{2\mathrm{Tr}}$

In formula, n is motor speed, and R is gear wheel radius, and r is pinion wheel radius, and T is the cycle of the indoor flood peak graph of water lev el control.

10. the using method for studying the simulation test model equipment that flood pulsed drive subsurface flow exchanges according to claim 6, it is characterized in that: in described 8th step, undercurrent exchange capacity between surface and ground water, also the undercurrent exchange capacity namely between Groundwater Control case and leaching beach, river model, for: Q _dive=Q _{go out}-Q _enter

In formula, Q _divefor the undercurrent exchange capacity between surface and ground water, Q _{go out}represent the discharge of underground water water delivering orifice in Groundwater Control case, Q _enterrepresent the influx of nourishment source in Groundwater Control case, work as Q _divefor on the occasion of showing that surface water is to ground water discharge, Q _divefor negative value shows recharge of ground water surface water.