CN102758416A - Device for researching flood discharge atomization spray source distributing regularity - Google Patents

Abstract

The invention relates to the field of high dam flood discharge atomization protection, in particular to a device for studying the distribution law of flood discharge atomization fog sources. Fog source volume observation device, flood discharge atomization fog source form observation device. Aiming at the deficiencies in the research devices of the distribution law of flood discharge atomization fog sources in the prior art, the research device proposed by the present invention can observe the physical phenomena of the collision of the deflector tongue into the water, the rebound of the water body, and the generation of splashing, and accurately measure the flood discharge atomization fog. source volume, capturing the fog source form within a certain period of time.

Description

A device for studying the distribution law of flood discharge atomization fog source

technical field

The invention relates to the field of high dam flood discharge atomization protection, in particular to a device for studying the distribution law of flood discharge atomization fog sources.

Background technique

During the flood discharge of water conservancy projects, especially high dam projects, large-scale rainfall and fog flow often appear in the downstream local area, which is called flood discharge atomization in the engineering field. Because the rainfall intensity (rain intensity) caused by it is generally as high as hundreds or even thousands of mm/h, far exceeding the rain intensity value (11.67mm/h) of the torrential rain in natural rainfall, it has great impact on the stability of the downstream bank slope of the water conservancy project. The normal operation of the hub buildings, traffic safety and the surrounding environment will cause great harm. The engineering hazards caused by flood discharge atomization remind us that we must fully recognize the hazards of flood discharge atomization in the engineering planning and design stages, and avoid or reduce its negative impact through effective protection measures. For this reason, many projects have begun to carry out special protection design for flood discharge atomization, and the main design basis is the prediction result of flood discharge atomization rainfall intensity and distribution. Therefore, the accuracy of the prediction results of flood discharge fog and rain has become the key factor to determine the success or failure of flood discharge fog protection design. Due to the complexity of the problem, the current prediction results cannot fully meet the needs of protection design, which has a great impact on the safe operation of the project. Improving the accuracy of the prediction results of flood discharge fog and rain has become the most important research direction in the research of flood discharge atomization.

Contents of the invention

A device for studying the distribution law of flood discharge atomization fog sources, including: a flood discharge simulation building, a collision, rebound and splash motion process observation device, a flood discharge atomization fog source quantity observation device, and a flood discharge atomization fog source shape observation device;

The simulated flood discharge structures include: high water tanks, generalized buildings, and downstream terrain buildings, and the high water tanks are used to provide water sources; the high water tanks can pass through the adjusted water level so that the water flow velocity is greater than 6m/s to eliminate surface tension To ensure that the aeration of the model water flow is basically similar to that of the prototype; at the same time, through the adjustment of the water level, the discharge flow rate is guaranteed to be 600L/s-800L/s, and the flow pattern is as similar as possible to the prototype.

The generalized building simulates the most widely used water-deflecting buildings at present; the generalized building is supported by a steel frame, and the end is provided with a nose sill, and the shape of the nose sill is designed as a continuous sill with different starting points Picking angle, which is used to simulate the flood discharge situation of different picking angles.

The downstream terrain building is provided with a trapezoidal river channel, and the side walls and bottom of the building are all made of light-transmitting plexiglass, and the bottom is partially elevated;

The observation device for the collision, rebound and splash movement process includes a high-speed camera arranged on one side, the bottom, and directly above the water tongue of the downstream terrain building, and the high-speed camera is used to observe the collision, rebound and splash movement process. When the water tongue enters the water and collides with it, the shape of the water tongue and the shape of the downstream water surface within the collision range; then study the underwater trajectory and operating range of the water tongue after entering the water; observe the movement elements such as the occurrence time of water body rebound and splash behavior.

Said flood discharge atomization mist source quantity observation device comprises the ground collecting device and the aerial collecting device arranged on the terrain building downstream; said ground collecting device includes being arranged on the water collecting box around the water splashing in the center and being arranged on the periphery of the water collecting box The drop spectrum test paper, in which the raindrops in the water collection box are weighed to calculate the amount of fog source, and the peripheral locations with small rainfall are measured by the drop spectrum method to improve the observation accuracy. The aerial collection device is a water collection box arranged along the splashing direction of water droplets above the splashing area, and is used to collect splashed raindrops (failed to enter the ground collection device) with a short flow process, and the results are combined with the raindrops collected on the ground for calculation . Among them, the weighing method weighs the collected water body through a precision electronic scale. The drop spectrum method is to use special dyed paper to collect raindrop samples, and calculate the true diameter of the collected raindrops according to the calibration curve between the diameter of the raindrop spot before sampling and the diameter of the raindrop in the air.

The device for observing the form of the flood discharge atomized fog source includes setting the background wall on both sides of the trapezoidal channel of the downstream terrain building at the water tongue entry position, setting the highlight lighting equipment and the smoke generator above the trapezoidal channel of the downstream terrain building, And set high-speed cameras on one side of the downstream terrain building, directly above the water tongue and in front of it. Capture the fog source form within a certain period of time through high-speed photography, analyze the time series of fog source form changes, and then combine them to form a fog source form spectrum in a complete sequence cycle. Through the self-developed flood discharge atomization particle size analysis software, image preprocessing (reduce the error caused by image quality), binarization processing (separate the target object from the background of the digital image, and separate the particles), and then image Carry out analysis, automatically detect important indicators such as the number of image particles, the area of image particles, and particle size, and obtain the actual parameter indicators of each particle, and then perform statistical analysis on the calibration parameters obtained through the pre-calibration test The number and diameter of water droplets. The exit angle of splashed water droplets can also be obtained through image analysis.

Previous research on water splashing was limited by research methods and testing techniques, and there were few studies on the physical mechanism of the impact, rebound, and splashing of the water splash tongue, especially the number, diameter distribution, and reflection angle of splashing water droplets. Research that has influenced the development of flood discharge fogging prediction methods. The device for studying the distribution law of flood discharge atomization fog source in the present invention includes a flood discharge building simulation system, a collision, rebound and splash motion process observation system, a flood discharge atomization fog source quantity observation system, and a flood discharge atomization fog source morphology observation system The system can observe the physical phenomena of the collision of the water tongue into the water, the rebound of the water body and the splashing; accurately measure the amount of fog source of flood discharge atomization; capture the shape of the fog source within a certain period of time.

Description of drawings

Figure 1 Simulated flood discharge buildings

Figure 2 Observation device for collision, rebound and splash motion

Figure 3 Flood discharge atomization fog source volume observation device

Figure 4 Flood discharge atomization fog source shape observation device

Reference signs: high water tank 1, generalized building 2, downstream terrain building 3, nose sill 4, steel frame 5, high-speed camera 6, ground collection device 7, aerial collection device 8, water collection box 9, drop spectrum test paper 10. Background wall 11, lighting equipment 12, smoke generator 13.

Detailed ways:

A device for studying the distribution law of flood discharge atomization and fog sources, including: a flood discharge building simulation system, an observation system for collision, rebound and splash motion process, a flood discharge atomization fog source quantity observation system, and a flood discharge atomization fog source shape observation system.

As shown in Figure 1, the simulated flood discharge structure includes: a high water tank 1, a generalized building 2, and a downstream terrain building 3, and the high water tank 1 is used to provide a water source; the high water tank 1 can make the water flow through the adjusted water level The flow velocity is greater than 6m/s to eliminate the influence of surface tension and ensure that the aeration of the model water flow is basically similar to the prototype; at the same time, through the adjustment of the water level, the discharge flow is 600L/s-800L/s to ensure that the flow pattern is similar to the prototype as much as possible.

The generalized building 2 simulates the most widely used water deflector building at present; the generalized building 2 is supported by a steel frame 5, and the end is provided with a nose sill 4, and the shape of the nose sill is designed as a continuous sill, and With different lifting angles, it is used to simulate the flood discharge situation of different lifting angles.

The downstream terrain building 3 is provided with a trapezoidal river channel, and the side walls and bottom of the building are all made of light-transmitting plexiglass, and the bottom is partly elevated.

As shown in Figure 2, the observation device for the collision, rebound and splash motion process includes a high-speed camera 6 arranged on one side of the downstream terrain building 3, the bottom and the top of the water tongue, and the high-speed camera 6 is used to observe the collision , Rebound and splash motion process.

As shown in Figure 3, the observation device for the amount of fog source of flood discharge atomization includes a ground collection device 7 and an aerial collection device 8 arranged on the downstream terrain building 3; The water collection box 9 around the water position and the drop spectrum test paper 10 arranged on the periphery of the water collection box 9, wherein the raindrops in the water collection box 9 are calculated by weighing the amount of fog source, and the peripheral rainfall is measured by the drop spectrum method. Raindrops are measured to improve observation accuracy. The air collecting device 8 is a water collection box 9 arranged along the splashing direction of water droplets above the splashing area, and is suspended above the splashing area by steel wires to collect splashed raindrops with a short flow (failed to enter the collecting device) , and combine the result with the raindrops collected on the ground.

As shown in Figure 4, the described flood discharge atomization mist source form observation device includes the background wall 11 arranged on both sides of the trapezoidal channel of the downstream terrain building 3 at the water tongue entry position, and the setting above the trapezoidal channel of the downstream terrain building 3 High-brightness lighting equipment 12 and smoke generator 13, and the high-speed camera 6 that is arranged on one side of the downstream terrain building, directly above the water tongue and in front.

Through the above-mentioned device, under the conditions of different discharge flow rates, nose sill water heads, and water entry angles, the research on the collision, rebound and splashing movement process of the water tongue entering the water, the research on the influencing factors of the amount of atomized fog source in flood discharge, and the distribution of atomized fog source in flood discharge Law study. The specific research methods are as follows:

(1) Research on the collision, rebound and splash motion process of the water tongue

Observe the physical phenomenon of water tongue collision, water body rebound and splashing, measure the shape of the water tongue and the shape change of the downstream water surface within the collision range when the water tongue enters the water; study the underwater trajectory and range of the water tongue after entering the water; observe Movement elements such as the occurrence time of water body rebound and splash behavior. The motion process is analyzed according to time series, and the motion process is described in combination with previous related research and relevant physical laws, and the calculation model of its motion process is preliminarily established.

(2) Research on factors affecting the amount of fog source in flood discharge

Since the splashing water droplets generated by the water tongue after entering the water show the characteristics of omni-directional distribution in space, that is to say, splashing water droplets will be generated around the water entering the water. For the convenience of description and subsequent analysis, the total amount of splashed water droplets generated is divided into longitudinal component and transverse component. The study intends to measure and analyze the longitudinal and transverse components of the splashing water droplets generated after the water tongue collides with the downstream water body within a certain period of time, and then calculate the total amount of splashing water droplets. And by changing the test conditions, the longitudinal and lateral components of splashed water droplets and the total amount of splashed water droplets under different water entry speeds, water entry angles and flow conditions are studied, and the amount of vertical and horizontal fog sources and the total amount of fog sources of flood discharge atomization are revealed. Quantitative response relationship with the main influencing factors.

(3) Study on the distribution law of flood discharge atomization fog source

After the water tongue enters the water and collides, the outer edge of the water tongue will produce a large number of splashing water droplets with different diameters, and they will be thrown around at different initial angles. The study intends to use high-speed photography equipment to capture the distribution of splashing water droplets around the outer edge of the water tongue, measure and analyze the number of splashing water droplets, the diameter of water droplets, and their respective exit angles, and study the distribution of flood discharge atomization fog sources. And by changing the test conditions, comparing the distribution patterns of flood discharge atomization fog sources under different water entry speeds, water entry angles and flow conditions of jetting water flow, combined with the research results of fog source volume to analyze the influence of different discharge conditions on the distribution of flood discharge atomization fog sources mechanism.

Claims (3)

1. a device of studying flood-discharge atomizing mist source distribution rule comprises: simulate flood releasing structure, collide, rebound and swash and spatters the motion process observation device, flood-discharge atomizing mist source discharge observation device, flood-discharge atomizing mist source form observation device; It is characterized in that:

Said simulation flood releasing structure comprises: high level cistern (1), generally change building (2), downstream landform buildings (3), said high level cistern (1) is used to provide the water source, and said generalization building (2) simulation is chosen and flowed water buildings;

Said downstream landform buildings (3) are provided with trapezoidal river course, and the organic glass of printing opacity is all adopted in the sidewall of building and bottom, and local built on stilts bottom;

Said collision, bounce-back and the sharp motion process observation device that spatters; Comprise being separately positioned on bottom downstream landform building (3) one sides, the downstream landform buildings (3) and the high-speed camera (6) directly over the overflow that said high-speed camera (6) is used for observation collision, bounce-back and the sharp motion process that spatters;

Said flood-discharge atomizing mist source discharge observation device comprises the surface collection apparatus (7) and the airborne acquisition device (8) that are provided with on the landform building of downstream;

Said flood-discharge atomizing mist source form observation device is included in that overflow entry position is arranged on lighting apparatus (12) that the top, trapezoidal river course of wall (11), the downstream landform buildings (3) of the both sides, trapezoidal river course of downstream landform buildings (3) is provided with and aerosol producer (13) and respectively directly over downstream landform building one side, overflow and the high-speed camera (6) of overflow the place ahead setting.

2. the device of research flood-discharge atomizing mist source distribution rule as claimed in claim 1; It is characterized in that said generalization building (2) supports through steelframe (5), the end is provided with bucket lip (4); Said bucket lip (4) build is designed to continuous bank, and has different rising and choose angle.

3. the device of research flood-discharge atomizing mist source distribution rule as claimed in claim 1; It is characterized in that; Said surface collection apparatus (7) comprises and dabbles around the position collecting box (9) when being arranged on the overflow entry and be arranged on the peripheral drop-size distribution test paper (10) of collecting box (9); Wherein the raindrop of the collection in the collecting box (9) calculate mist source amount through weighing, and the less position of peripheral amount of precipitation is measured raindrop through the drop-size distribution method; Said airborne acquisition device (8) is for swashing the collecting box (9) that spatters the direction setting along water droplet above the zone that dabbles.

Images