In-situ low-deflection hydrographic measurement device

Abstract

The invention discloses an in-situ low-deflection hydrological survey device, and belongs to the technical field of hydrological survey. The device comprises a low-deflection measuring body, an empennage system, a still water chamber and a measurement control system. The head of the measuring body is of a streamline structure to greatly reduce flow field disturbance. The cross-shaped empennage system provides hydrodynamic force damping, pitching, rolling and yawing movement of the device underwater is effectively restrained, and it is guaranteed that the measuring posture is stable. And the still water chamber is communicated with the outside through a plurality of permeable channels. During measurement, the on-off of the valve is controlled, and the water density is inversed according to the measured value change of the pressure sensor in the still water chamber so as to calculate the sand content; meanwhile, the flow velocity is calculated through the difference between the total water flow pressure and the static pressure sensed by the measuring device body and the real-time density. The device can realize synchronous, in-situ and high-frequency online measurement of the flow velocity and the sand content of the same microscopic water body unit, and has the advantages of high precision, good stability and strong environmental adaptability.

Description

Technical Field

[0001] This invention relates to the technical field of hydrological measurement, and more particularly to an in-situ low-disturbance hydrological measurement device. Background Technology

[0002] Hydrological surveys are fundamental to water resources management, water conservancy project construction, flood and drought forecasting, and water science research. Among these, water flow velocity and sediment content are two of the most critical hydrological elements, and accurately obtaining their data is of great significance for studying riverbed evolution, assessing reservoir siltation, and simulating pollutant diffusion.

[0003] Currently, the measurement of current velocity and sediment concentration at fixed underwater points typically employs a combination of discrete sensors. Current velocity measurements are mostly based on the acoustic Doppler principle (such as ADCP and ADV) or the mechanical rotor principle (such as propeller-type current meters); while sediment concentration measurements primarily utilize optical turbidity methods. However, these traditional technical solutions have several inherent drawbacks:

[0004] Measurement interference and errors: Whether acoustic or optical sensors, their probes themselves can interfere with the flow field to varying degrees, disrupting the original structure of the flow field and introducing measurement errors. For example, the presence of support rods and sensor probes can generate wake vortices and flow separation, making the measured values ​​not the true original flow field values.

[0005] Synchronization and location discrepancies: Flow velocity sensors and sediment concentration sensors are typically two independent units. Even when integrated into a single frame, their sampling volumes and locations differ physically. This "different points, simultaneous measurement" approach makes it difficult to truly reflect the correspondence between instantaneous flow velocity and sediment concentration within the same microscopic water body, introducing uncertainty into subsequent data correlation and analysis.

[0006] Poor adaptability to high sediment content environments: Optical sensors are prone to window fouling and signal saturation in high sediment content water bodies, resulting in a sharp drop in measurement accuracy; Acoustic sensors will also fail in water bodies containing a large number of air bubbles or fine sediment particles due to abnormal signal attenuation.

[0007] Mechanical structure reliability issues: The rotor of the propeller-type current meter is easily entangled and jammed by aquatic plants and floating objects, resulting in high maintenance costs and unresponsive start-up at low flow rates.

[0008] In addition, existing online measurement devices are prone to high-frequency pitch ("nodding") and yaw ("shaking") oscillations in complex flow fields, especially turbulent flow, which leads to sensor attitude instability and further increases the fluctuation and unreliability of measurement data.

[0009] Therefore, there is an urgent need for a new type of device that can achieve low flow field disturbance, high attitude stability, and synchronous in-situ measurement of flow velocity and sediment concentration at fixed underwater locations, in order to overcome the limitations of existing technologies and improve the accuracy and reliability of hydrological measurement data. Summary of the Invention

[0010] The purpose of this invention is to provide an in-situ low-disturbance hydrological measurement device to overcome the shortcomings of the prior art.

[0011] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0012] An in-situ low-deflection hydrological measurement device includes a low-deflection measuring body, a tail fin system, a still water chamber, and a measurement and control system.

[0013] The front part of the low-deflection measuring body has a streamlined structure with continuous curvature;

[0014] The tail fin system is fixedly mounted at the rear of the low-deflection test object;

[0015] The still water chamber is located inside the cavity of the low-disturbance measuring body; the still water chamber is connected to the outer surface of the low-disturbance measuring body through several water-permeable channels.

[0016] The measurement and control system includes a controller, a control valve installed on the permeable channel, a pressure sensor and a pressure sensor installed in the still water chamber. The control valve is used to control the opening and closing of the permeable channel, the pressure sensor is used to measure the pressure in the still water chamber, and the pressure sensor is used to measure the water flow pressure. The controller is connected to the control valve, the pressure sensor and the pressure sensor respectively, and can control the opening and closing of the control valve, and receive and store the pressure and pressure signals transmitted from the pressure sensor and the pressure sensor.

[0017] Further improvements to optimize the technical solution include:

[0018] The aforementioned tail fin system is a cruciform tail fin composed of a horizontal tail fin and a vertical tail fin, both of which are fixedly installed at the rear of the low-disturbance measuring body.

[0019] The horizontal tail fin has a span greater than its chord length to suppress the pitch and roll motion of the measuring device; the vertical tail fin has a height greater than its width to resist the lateral impact of the water flow and prevent the measuring device from yawing.

[0020] There are three permeable channels: a front permeable channel, an upper permeable channel, and a lower permeable channel. The two ends of the front permeable channel are connected to the front end of the still water chamber and the front end of the low-deflection measuring body, respectively. The upper permeable channel is connected to the upper end of the still water chamber and the upper end of the low-deflection measuring body, respectively. The lower permeable channel is connected to the lower end of the still water chamber and the lower end of the low-deflection measuring body, respectively. Correspondingly, a first valve is installed on the front permeable channel, a second valve is installed on the upper permeable channel, and a third valve is installed on the lower permeable channel.

[0021] The aforementioned pressure sensor includes a first pressure sensor and a second pressure sensor. The pressure-bearing surface of the first pressure sensor is perpendicular to the water flow direction and is used to measure the water flow pressure; the pressure-bearing surface of the second pressure sensor is parallel to the water flow direction and is used to measure the water flow static pressure.

[0022] The aforementioned still water chamber is connected to a drain channel at its rear end. The drain channel opens at the rear of the low-deflection measuring body. A fourth valve is installed on the drain channel. The fourth valve is connected to a controller, which can control the opening and closing of the fourth valve.

[0023] The first valve, second valve, third valve and fourth valve mentioned above are all solenoid valves.

[0024] The aforementioned measurement and control system also includes batteries, which are connected to and power each valve and controller.

[0025] The controller described above is connected to a wireless transceiver, through which the controller sends or receives signals to or from the outside.

[0026] The aforementioned low-disturbance measuring body is made of corrosion-resistant metal materials or engineering plastics, and its outer surface is coated with a smooth waterproof coating.

[0027] The technical advantages of this invention are as follows:

[0028] 1. The device of this invention features a streamlined shape with continuous curvature at the front, which guides water flow extremely smoothly, significantly reducing the high-pressure zone and flow field distortion in front of the measuring body, thereby minimizing damage to the original flow field. This low-disturbance characteristic provides a near-realistic fluid environment for flow velocity and sediment concentration measurements, fundamentally ensuring the accuracy of the basic data.

[0029] 2. The unique cruciform tail system of this invention provides the device with excellent hydrodynamic damping characteristics. The horizontal tail effectively suppresses pitch and roll motions, while the vertical tail resists lateral impacts and yaw tendencies. This allows the device to maintain an extremely stable attitude even in complex turbulent environments, effectively avoiding data fluctuations and measurement errors caused by high-frequency oscillations of the device (such as "nodding" or "shaking"), and ensuring the consistency and reliability of long-term measurements.

[0030] 3. This invention enables the inversion of sediment concentration by measuring pressure changes within the same still water chamber, while simultaneously calculating flow velocity using the dynamic and static pressure difference sensed by the device itself. The two measurements are completely synchronized in time and originate from the same microscopic water body unit in space, thoroughly solving the inherent defects of traditional discrete sensors where measurement locations differ and data matching is difficult. This provides unprecedented high-quality, highly correlated data for the precise study of the interaction mechanism between water flow and sediment movement.

[0031] 4. This invention exhibits excellent environmental adaptability and operational reliability. Its core measurement is based on mechanical principles, making it insensitive to factors such as water transmittance and bubble content. Its anti-interference capability far surpasses that of optical methods, which are easily contaminated, and acoustic methods, which are easily affected by sediment. It is particularly adept at long-term stable operation under extreme hydrological conditions such as high sediment content. Furthermore, the device has no easily damaged moving parts, fundamentally avoiding entanglement, jamming, and other malfunctions. Its robust structure requires minimal maintenance, significantly improving reliability.

[0032] 5. The entire measurement process of this invention, including valve opening and closing, sensor data acquisition, calculation and storage, can be automatically completed by the built-in controller, and data can be transmitted wirelessly remotely. This achieves unattended, high-frequency, online continuous measurement, greatly freeing up manpower and improving the efficiency and modernization level of hydrological monitoring. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the external structure of the first embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the internal structure of the first embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the external structure of the second embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the internal structure of the second embodiment of the present invention;

[0037] The attached figures are labeled as follows: Low-disturbance measuring body 1, Tail fin system 2, Horizontal tail fin 21, Vertical tail fin 22, Still water chamber 3, Measurement and control system 4, Controller 41, Control valve 42, First valve 42a, Second valve 42b, Third valve 42c, Fourth valve 42d, Pressure sensor 43, Pressure sensor 44, First pressure sensor 44a, Second pressure sensor 44b, Battery 45, Water permeable channel 5, Front water permeable channel 51, Upper water permeable channel 52, Lower water permeable channel 53, Drainage channel 6. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0039] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0040] First embodiment:

[0041] like Figures 1 to 2 As shown, the in-situ low-disturbance hydrological measurement device provided by the present invention mainly consists of a low-disturbance measuring body 1, a tail fin system 2, a still water chamber 3, and a measurement and control system 4.

[0042] The low-disturbance measuring body 1 has an overall streamlined structure in the shape of a teardrop or torpedo. Its front part is a smooth curved surface with continuous curvature, which is used to smoothly divert and guide the water flow when traveling in water, minimizing the high-pressure area and flow separation phenomenon in front, and reducing the disturbance to the original flow field. The low-disturbance measuring body 1 can be integrally molded from corrosion-resistant 316 stainless steel or high-strength engineering plastic through a mold, and its outer surface is sprayed with a polyurethane waterproof smooth coating to further reduce flow resistance.

[0043] The tail fin system 2 is fixed to the rear of the low-disturbance measuring body 1 via flange connection or embedded welding. The tail fin system 2 is a cross-shaped structure formed by the orthogonal horizontal tail fin 21 and vertical tail fin 22. The horizontal tail fin 21 and vertical tail fin 22 are directly fixed to the rear of the low-disturbance measuring body 1, but the horizontal tail fin 21 and vertical tail fin 22 are not directly connected.

[0044] The horizontal tail fin 21 has a span greater than its chord length to provide sufficient area to suppress the pitch and roll motion of the device underwater; the vertical tail fin 22 has a height greater than its width to effectively resist the impact of lateral water flow and prevent the device from yawing, thereby maintaining a stable attitude throughout the measurement process.

[0045] The still water chamber 3 is a sealed cavity located inside the low-disturbance measuring body 1. The still water chamber 3 is connected to the external aquatic environment through three permeable channels 5. Specifically, the front permeable channel 51 connects the front end of the still water chamber 3 to the center of the head of the low-disturbance measuring body 1; the upper permeable channel 52 connects the upper end of the still water chamber 3 to the upper surface of the low-disturbance measuring body 1; and the lower permeable channel 53 connects the lower end of the still water chamber 3 to the lower surface of the low-disturbance measuring body 1. The inlet directions of these three channels are all designed with fluid dynamics in mind, ensuring that their opening axes are parallel to the local streamlines on the outer surface of the low-disturbance measuring body 1 to avoid generating additional flow disturbances. Furthermore, a drain channel 6 is connected to the rear end of the still water chamber 3.

[0046] The measurement and control system 4, integrated within the low-disturbance measuring body 1, is the core of the device. It includes:

[0047] Controller 41: A low-power microprocessor (such as the STM32L series) is used as the control center.

[0048] Control valves 42: There are four in total, all of which are waterproof solenoid valves. Among them, the first valve 42a, the second valve 42b, and the third valve 42c are respectively installed on the front permeable channel 51, the upper permeable channel 52, and the lower permeable channel 53; the fourth valve 42d is installed on the drain channel 6. All valves are electrically connected to the controller 41 and receive its commands to open and close.

[0049] Pressure sensor 43: Its pressure sensing diaphragm is directly exposed inside the still water chamber 3, and is used to measure the pressure changes of the fluid in the still water chamber 3 at high frequency and with high precision.

[0050] Pressure sensor 44: Includes two independent sensors. The first pressure sensor 44a is a total pressure sensor, with its sensing orifice located at the front of the still water chamber 3 and its pressure sensing diaphragm facing the incoming flow direction, used to measure the total pressure of the water flow. The second pressure sensor 44b is a static pressure sensor, with its sensing orifice located at the rear of the still water chamber 3 and its pressure sensing diaphragm parallel to the incoming flow direction, used to accurately measure the static pressure of the water flow.

[0051] Battery 45: Employs a high-capacity lithium thionyl chloride battery pack to provide long-term, stable power for the entire measurement and control system 4.

[0052] Wireless transceiver: Integrated on the circuit board of controller 41, it supports 4G / NB-IoT or LoRa wireless communication protocols and is used for data interaction and command reception with the remote monitoring center.

[0053] Second embodiment:

[0054] like Figure 3-4As shown, the horizontal tail fin 21 and the vertical tail fin 22 are interconnected and located at the rear end of the low-disturbance measuring body 1. An exhaust channel 6 is also connected to the rear end of the still water chamber 3, with its outlet opening at the tail of the low-disturbance measuring body 1.

[0055] The working principle and process of this invention are as follows:

[0056] Initial preparation state: Before the device is submerged, the fourth valve 42d is closed, and the first, second, and third valves are open. The still water chamber 3 and the permeable channel 5 are filled with pure water (density...). =1000kg / m³). Then all valves are closed, and the still water chamber 3 becomes a sealed "reference chamber". Controller 41 controls pressure sensor 43 to measure and record the initial internal pressure value N0 at this time.

[0057] Measurement Status: After the device is deployed to the predetermined underwater measurement point, the controller 41 issues a command to open the first, second, and third valves, while keeping the fourth valve 42d closed. External water slowly flows into the still water chamber 3 through the three permeable channels 5. Due to the pressure balancing effect of the multiple channels, the still water chamber 3 quickly reaches fluid equilibrium. At this time, the controller 41 simultaneously collects data from the three sensors:

[0058] Read the new pressure value N1 from pressure sensor 43.

[0059] The sediment content (CS) of the water body at this time can be obtained:

[0060]

[0061] Simultaneously, the reading from the first pressure sensor 44a, i.e., the water flow pressure, is also recorded. The second pressure sensor 44b measures the water flow pressure. The formula for calculating the flow velocity V at that point is:

[0062]

[0063] In the formula, C represents the instrument coefficient obtained in advance through the calibration of the water tank using a flow meter.

[0064] Drainage and Reset: After a measurement is completed, controller 41 closes the first, second, and third valves and opens the fourth valve 42d to drain the turbid water in the still water chamber 3 through the drainage channel 6. The fourth valve 42d can then be closed again to prepare for the next measurement.

[0065] Data transmission: The data obtained from the measurement calculation can be temporarily stored in the flash memory of the controller 41, or transmitted in real time to the shore station or cloud platform via a wireless transceiver.

[0066] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. An in-situ low-deflection hydrological measurement device, characterized in that, It includes a low-disturbance measuring body (1), a tail fin system (2), a still water chamber (3), and a measurement and control system (4); The front part of the low-deflection measuring body (1) is a streamlined structure with continuous curvature; The tail fin system (2) is fixedly installed at the rear of the low-deflection measuring body (1); The still water chamber (3) is located in the internal cavity of the low-disturbance measuring body (1); the still water chamber (3) is connected to the outer surface of the low-disturbance measuring body (1) through several water-permeable channels (5). The measurement and control system (4) includes a controller (41), a control valve (42) installed on the permeable channel (5), a pressure sensor (43) and a pressure sensor (44) installed in the still water chamber (3). The control valve (42) is used to control the opening and closing of the permeable channel (5), the pressure sensor (43) is used to measure the pressure in the still water chamber (3), and the pressure sensor (44) is used to measure the water flow pressure. The controller (41) is connected to the control valve (42), the pressure sensor (43) and the pressure sensor (44) respectively, and can control the opening and closing of the control valve (42), and receive and store the pressure and pressure signals transmitted from the pressure sensor (43) and the pressure sensor (44).

2. The in-situ low-disturbance hydrological measurement device according to claim 1, characterized in that, The tail fin system (2) is a cross-shaped tail fin composed of a horizontal tail fin (21) and a vertical tail fin (22). The horizontal tail fin (21) and the vertical tail fin (22) are both fixedly installed at the rear of the low-disturbance measuring body (1).

3. The in-situ low-deflection hydrological measurement device according to claim 2, characterized in that, The horizontal tail fin (21) has a span greater than its chord length to suppress the pitch and roll motion of the measuring device; the vertical tail fin (22) has a height greater than its width to resist the lateral impact of the water flow and prevent the measuring device from yawing.

4. The in-situ low-deflection hydrological measurement device according to claim 1, characterized in that, There are three permeable channels (5): a front permeable channel (51), an upper permeable channel (52), and a lower permeable channel (53). The two ends of the front permeable channel (51) are connected to the front end of the still water chamber (3) and the front end of the low-disturbance measuring body (1), respectively. The upper permeable channel (52) is connected to the upper end of the still water chamber (3) and the upper end of the low-disturbance measuring body (1), respectively. The lower permeable channel (53) is connected to the lower end of the still water chamber (3) and the lower end of the low-disturbance measuring body (1), respectively. Correspondingly, a first valve (42a) is installed on the front permeable channel (51), a second valve (42b) is installed on the upper permeable channel (52), and a third valve (42c) is installed on the lower permeable channel (53).

5. The in-situ low-disturbance hydrological measurement device according to claim 1, characterized in that, The pressure sensor (44) includes a first pressure sensor (44a) and a second pressure sensor (44b). The first pressure sensor (44a) is used to measure the water flow pressure, and the second pressure sensor (44b) is used to measure the water flow static pressure.

6. The in-situ low-disturbance hydrological measurement device according to claim 4, characterized in that, The rear end of the still water chamber (3) is connected to a drain channel (6), which opens at the rear of the low-disturbance measuring body (1). A fourth valve (42d) is installed on the drain channel (6), which is connected to a controller (41). The controller (41) can control the opening and closing of the fourth valve (42d).

7. The in-situ low-disturbance hydrological measurement device according to claim 6, characterized in that, The first valve (42a), the second valve (42b), the third valve (42c), and the fourth valve (42d) are all solenoid valves.

8. The in-situ low-disturbance hydrological measurement device according to claim 7, characterized in that, The measurement and control system (4) further includes a battery (45), which is connected to and powers each valve and controller (41).

9. The in-situ low-disturbance hydrological measurement device according to claim 8, characterized in that, The controller (41) is connected to a wireless transceiver, and the controller (41) sends or receives signals to the outside through the wireless transceiver.

10. The in-situ low-disturbance hydrological measurement device according to claim 1, characterized in that, The low-disturbance measuring body (1) is made of corrosion-resistant metal material or engineering plastic, and its outer surface is coated with a smooth waterproof coating.

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