RU2033491C1 - Device for determination of permissible noneroding velocity of water flow for ground - Google Patents

Abstract

FIELD: hydraulic engineering. SUBSTANCE: device for determination of permissible noneroding velocity of water flow for ground is made in form of vertical cylindrical vessel 1 additionally furnished with vertical hollow cylinder 2 coaxially installed in vessel 1 and forming annular hollow together with vessel walls and circular horizontal plate 8 with water passing holes installed in annular hollow to separate it into upper working chamber 7 and lower filling chamber 6 and intake and discharge pipes 22 located on the bottom of vessel 1. Circular horizontal plate 8 has radial recess 10 in which holder 11 with ground 12 is installed. Installed in plate 8 flush with its upper surface are transducers 13 of tangential stresses which serve to measure bottom flow velocity. Installed on walls 3 and 4 of vessel 1 and cylinder 2 are radiator 16 and receiver of modulated light. After filling of water chamber 7 and initiating water flow, ground 12 is observed. When turbidity of flow rises and eroding zone is formed in ground 12, flow velocity is registered by transducers 13 of tangential stresses or laser velocity meters. EFFECT: higher efficiency. 3 cl, 2 dwg

Description

 The invention relates to hydraulic engineering, namely, to establish the values of the permissible non-washable speed of the flow of water for various soils.

 There are various devices for determining the values of permissible non-washable soil water flow rates, for example, a device in the form of a rectilinear tray, in the bottom of which a test soil sample is installed [1] The disadvantages of this device are cumbersome, complexity, the need for a sequential stepwise increase in flow rate, which leads to duration tests, as well as the need to equip the tray with external devices: pool, pump, pipelines.

The closest technical solution to the proposed device is a device for determining the permissible non-washable velocity of the water flow for the soil, including a vertical vessel with a water flow pathogen, at the bottom of the vessel there is a radial groove in which the soil sample is placed, and water velocity sensors located radially at the bottom vessel [2]
This device has insufficient measurement accuracy, since there may be a violation of the hydraulic structure of the flow in the central zone, speed sensors are removed from the bottom, there is no device for fixing the beginning of the soil erosion process. When filling the vessel with water, damage to an already established soil sample is possible.

 The aim of the invention is the creation of a compact device for determining the permissible non-washable speed of the water flow for the soil, which allows to increase the accuracy of measurements, modeling accuracy and expand the scope of the device due to the possibility of testing various soils.

 To do this, in the device for determining the permissible non-washing speed of the water flow for the soil, including a vertical cylindrical vessel with a pathogen of rotation of the water flow, a turbidity meter, a device for measuring flow velocity and a soil sample, the vertical cylindrical vessel is equipped with a vertical hollow cylinder coaxially mounted in the vessel and forming an annular cavity with the walls of the vessel, and an annular horizontal plate with culverts installed in the annular cavity and lasking it on the upper working and lower filling chambers, and the supply and drain tubes located in the bottom of the vessel; the turbidity meter is made in the form of a modulated light emitter and receiver placed opposite each other, one of which is installed in the cylinder on its wall, and the other on the vessel wall, and a recording device connected to them, the plate being made with a radial groove for installing a soil sample and equipped with interchangeable coatings with various roughness.

 The device for measuring the flow velocity can be made in the form of tangential stress sensors mounted on the plate flush with its upper surface and calibrated in the testimony of bottom velocities.

 To measure bottom flow rates, laser gauges of water flow rates can be installed on the walls of the annular vessel, which makes it possible to increase the accuracy of measurements and avoid disturbance of the hydraulic structure of the flow, since no additional interference is introduced into the flow.

 The coaxial installation of an additional vertical hollow cylinder, which forms an annular and central cavity together with the outer one, creates an annular channel, which reduces the likelihood of a central vertical vortex, funnel, and perturbation in the flow, which prevents the violation of the specified mode. The annular channel allows you to expose the soil sample at the same time to different speeds corresponding to different radii.

 The vertical hollow cylinder also serves for the installation of measuring instruments in it, which, compared with the prototype, significantly increases the accuracy of measurements and ease of maintenance of devices. The accuracy and reliability of the measurements is also increased due to the fact that it is possible to control each target of the annular channel, in the prototype there is no such possibility. The use of shear stress sensors mounted on the slab flush with its upper surface and calibrated in the indications of bottom velocities of the water flow helps prevent disturbance of the hydraulic structure of the flow in the bottom zone and determines the erosive effect of the flow on the bottom surface and, accordingly, on the soil sample installed in the groove.

 The presence of removable coatings with different roughness on an annular horizontal plate allows us to expand the scope of the device when working with various soils due to the correct modeling of the real bottom and hydraulic flow structure.

 On the walls of the vessels, outside the working chamber, at the level of its bottom and parallel to it, an emitter and a modulated light receiver with a recording device are installed, which makes it possible to determine the increase in the turbidity of the stream and to record with high accuracy the beginning of separation of soil particles (the beginning of the erosion process).

 The implementation of culverts on the annular horizontal plate and in the bottom of the filling chamber of the supply pipe allows for smooth filling of the working chamber through the filling chamber, which eliminates premature soil damage and thereby eliminates the noted disadvantage of the prototype, where filling takes place from above.

 Thus, the proposed device for determining the permissible non-washable speed of the water flow for the soil improves the accuracy of measurements, the accuracy of modeling, ease of use and expands the scope.

 In FIG. 1 shows the proposed device, a General view; in FIG. 2 same, plan view.

 The device for determining the permissible non-washing speed of the water flow for the soil consists of a vertical annular vessel 1 and a vertical hollow cylinder 2. An annular vessel (annular cavity) 1 is formed by the outer 3 and inner 4 cylindrical walls made of transparent material. The device contains a pathogen of rotation of the water stream 5.

 The annular vessel 1 is made of two-chamber, consisting of a filling chamber 6 and a working chamber 7, separated by a horizontal horizontal plate 8 with the culvert holes 9 contained in it, a groove 10 is made in the bottom of the plate 8, into which a cassette 11 with a soil sample 12 is inserted, the surface of which is made flush with the bottom of the plate 8. In the plate 8 radially installed a number of sensors of tangential stresses 13, calibrated in the readings of the speeds of the water flow. The sensors 13 are connected to the transducer 14 and the recording device 15. On the walls 3, 4 of the annular vessel 1, outside the working chamber 7, an emitter 16 is installed with a generator 17 and a modulated light receiver 18 connected to an amplifier 19 and a recorder 20. At the bottom of the filling chamber 6 a supply and drain pipe 22 is installed; laser meters (not shown) can be mounted on the walls of the cylindrical vessel on the walls 3, 4 of the annular vessel.

 The device operates as follows.

 In the groove 10 located in the plate 8, a cassette 11 with a sample of soil 12 is installed. Through the pipe 22 of the filling chamber 6 and the culvert holes 9 of the plate 8, water is supplied to the working chamber 7 of the annular vessel 1 and filled until contact with the pathogen of rotation of the water stream 5. Turbidity and water temperature are selected in accordance with the field conditions or with the experimental conditions.

 The causative agent of rotation of the water stream 5 causes water to rotate, gradually increase the speed and observe the soil 12 visually, and the turbidity of the stream using modulated light radiation emitted by the emitter 16, 17 and received by the transducer 14 with the recording device 15.

 With increasing turbidity of the flow and the formation of the zone of erosion of the soil 12, 12 ', the water flow rate is fixed by tangential stress sensors 13 and laser meters (not shown in the drawing).

 This speed is the boundary erosion speed, lower speeds are non-blurring for a given soil 12. If the surface of the soil 12 has a significant roughness, replaceable coatings with the appropriate roughness are installed on the plate 8.

 Thus, the proposed device is compact and allows to increase the accuracy of measurements, the accuracy of modeling, to expand the scope of the device compared to the prototype.

Claims (3)

 1. DEVICE FOR DETERMINING THE ACCEPTABLE NON-SILING WATER FLOW SPEED FOR SOIL, including a vertical cylindrical vessel with a pathogen of rotation of the water flow, a turbidity meter, a device for measuring flow velocity and a soil sample, characterized in that it is equipped with a vertical hollow cylinder, coaxially installed and forming an annular cavity with the walls of the vessel, an annular horizontal plate with culverts, installed in the annular cavity and dividing it into the upper the working and lower filling chambers, and the supply and drain pipes located in the bottom of the vessel, and the turbidity meter is made in the form of emitter and a modulated light receiver placed opposite each other, one of which is installed in the cylinder on its wall and the other on the vessel wall with its outer side, and a recording device connected to them, the plate being made with a radial groove for installing a soil sample and provided with a replaceable coating with roughness.  2. The device according to claim 1, characterized in that the device for measuring the flow velocity is made in the form of shear stress sensors mounted on the plate flush with its upper surface and calibrated in the bottom velocity readings.  3. The device according to claim 1, characterized in that the device for measuring the flow rate is made in the form of laser speed meters mounted on the walls of the cylinder and vessel.

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