Ship propeller wake flow electric field test system and test method

Abstract

The invention belongs to the technical field of underwater electric field testing, and discloses a ship propeller wake flow electric field testing system and method. The system comprises a front-end sensing unit, a signal amplification and acquisition unit, a data transmission control unit, an upper computer and a power supply unit, the front-end sensing unit comprises a sensing module, the sensing module comprises a plurality of electric field sensors, and the plurality of electric field sensors are utilized to form a three-dimensional grid type measuring net; the data transmission control unit comprises a clock synchronization module; the front-end sensing unit is used for acquiring electric field signals of ship propeller wake flow in a three-dimensional space, the signal amplification acquisition unit is used for carrying out amplification conditioning and analog-to-digital conversion on the received electric field signals, and the data transmission control unit is used for transmitting synchronously processed data to the upper computer. And analyzing, processing and displaying the received data by using the upper computer to obtain ship propeller wake flow electric field test information. According to the invention, the spatial distribution and propagation condition of the wake flow electric field of the ship propeller can be measured finely.

Description

Technical Field

[0001] The present invention belongs to the technical field of underwater electric field testing, and more specifically, relates to a ship propeller wake electric field testing system and a testing method. Background Art

[0002] The propeller wake of a ship refers to the fluid vortex generated by the rotation of the propeller. The electric field of the propeller wake of a ship refers to the electric field generated by the movement of the water body driven by the propeller of the ship. Due to the complex spatial distribution of the electric field of the propeller wake of a ship, the testing is difficult. There is currently no targeted testing system. The electric field strength at a certain point or a certain part can only be measured by a commonly used underwater electric field measurement device. It is impossible to effectively measure the electric field distribution in a large-scale space. In addition, the measurement profile of the existing scheme is single, and it can usually only measure the electric field distribution of one plane, which is not enough to quantitatively analyze the propagation of the electric field in a large-scale space. In addition, the measurement sensitivity of the existing scheme is poor, which is not enough to be used to measure the weak electric field signals caused by the propeller wake. In summary, it is difficult for the existing technology to make precise measurements of the spatial distribution and propagation of the electric field of the propeller wake of a ship. Summary of the invention

[0003] The present invention solves the problem that it is difficult to precisely measure the spatial distribution and propagation of the ship propeller wake electric field in the prior art by providing a ship propeller wake electric field testing system and a testing method.

[0004] The present invention provides a ship propeller wake electric field test system, comprising: a front-end sensing unit, a signal amplification and acquisition unit, a data transmission control unit, a host computer and a power supply unit; the front-end sensing unit comprises a sensing module, the sensing module comprises a plurality of electric field sensors, and a three-dimensional grid-type measurement network is formed by utilizing the plurality of electric field sensors; the front-end sensing unit is used to obtain the electric field signal of the ship propeller wake in a three-dimensional space, and transmit the electric field signal to the signal amplification and acquisition unit; the signal amplification and acquisition unit is used to amplify, condition and perform analog-to-digital conversion on the received electric field signal, and then transmit the signal to the data transmission control unit; the data transmission control unit comprises a clock synchronization module; the data transmission control unit is used to transmit the synchronized data to the host computer; the host computer is used to analyze, process and display the received data; the power supply unit is used to provide power to the signal amplification and acquisition unit and the data transmission control unit.

[0005] Preferably, the front-end sensing unit also includes an array bracket and a watertight cable; the array bracket includes a plurality of brackets, and the plurality of brackets are constructed to form an array structure, and a ship propeller wake channel is reserved; the electric field sensor and the watertight cable are both installed on the array bracket, the electric field sensor is connected to the watertight cable, and the watertight cable is connected to the signal amplification and acquisition unit.

[0006] Preferably, the array bracket also includes a plurality of adapter devices, which are installed on the bracket, each of which includes a plurality of tubular interfaces located within the same measuring point range and facing different measuring directions, and an electric field sensor is installed within each measuring point range, and the electric field sensor is placed in the tubular interface facing the required measuring direction.

[0007] Preferably, the array bracket is made of non-metallic material.

[0008] Preferably, a plurality of the brackets are constructed to form a two-layer array structure, with 12 to 48 electric field sensors arranged on each layer, the distance between two adjacent electric field sensors on the same layer is 1m to 3m, and the distance between two adjacent electric field sensors on different layers is 2m to 4m.

[0009] Preferably, the front-end sensing unit further comprises a suction cup, and the suction cup is used to adsorb the array bracket to the pool wall and / or pool bottom of the test water pool.

[0010] Preferably, the electric field sensor uses a dual carbon substrate Ag-rGO-CF composite electrode as a probe, the electrode sensitivity is <1nV / m@1Hz, and the self-noise is <1nV / Hz 0.5 @1Hz, potential difference drift <40μV / 24h.

[0011] Preferably, the clock synchronization module uses a nanosecond atomic clock as a synchronization clock.

[0012] Preferably, the signal amplification and acquisition unit includes a weak signal amplification module, a signal conditioning module, an AD acquisition module and an FPGA control module; the data transmission control unit also includes a multi-channel data processing module and a multi-channel data communication module; the host computer includes a data analysis and processing module, a data communication module and a display control module.

[0013] On the other hand, the present invention provides a ship propeller wake electric field testing method, which is implemented by using the above-mentioned ship propeller wake electric field testing system, and the ship propeller wake electric field testing method comprises the following steps:

[0014] The electric field signal of the propeller wake of the ship in three-dimensional space is obtained by using the front-end sensing unit and transmitted to the signal amplification and acquisition unit;

[0015] The signal amplification and acquisition unit is used to amplify and condition the received electric field signal and perform analog-to-digital conversion, and then transmit the signal to the data transmission control unit;

[0016] Utilize the data transmission control unit to transmit the synchronized data to the host computer;

[0017] The host computer is used to analyze, process and display the received data to obtain ship propeller wake electric field test information.

[0018] One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

[0019] (1) The ship propeller wake electric field test system provided by the present invention includes a front-end sensing unit, a signal amplification and acquisition unit, a data transmission control unit, a host computer and a power supply unit, wherein the front-end sensing unit includes a sensing module, and the sensing module includes a plurality of electric field sensors. The present invention uses a plurality of electric field sensors to form a three-dimensional grid-type measurement network, and the front-end sensing unit can be used to obtain the electric field signal of the ship propeller wake in the three-dimensional space. That is, the present invention uses a plurality of electric field sensors to construct a three-dimensional grid-type measurement system, which includes a plurality of measurement points, and the measurement section is no longer limited to a certain plane, so that the electric field distribution in a large-scale space can be effectively measured, and multi-scale wake electric field data (potential difference data) can be collected and obtained, which is conducive to analyzing the electric field signals in different spaces at the same time. And the data transmission control unit in the present invention includes a clock synchronization module, and the data transmission control unit can be used to transmit the synchronized data to the host computer, thereby obtaining a high-precision measurement result. That is, the present invention uses a high-precision clock synchronization acquisition method to ensure that the time accuracy of the collected data is extremely high, so that the electric field data of each orientation of the synchronous measurement is more accurate, and the spatial distribution of the wake electric field can be tested to change with time. In summary, the present invention can accurately measure the spatial distribution and propagation of the electric field of the ship propeller wake.

[0020] (2) The layout of the measurement network of the present invention has the characteristics of multi-layer (for example, two-layer) three-dimensional spatial distribution, which can ensure the effective measurement of the three-dimensional spatial electric field information of the wake. Since the test target of the present invention is a moving target, specifically a ship propeller wake, in order to avoid the dynamic interference of the moving target to the test system as much as possible (for example, causing the electric field sensor to shake), the present invention uses a plurality of brackets to build an array structure while reserving a ship propeller wake channel in view of the characteristics of the ship propeller wake, ensuring that the frame structure is not located in the wake main channel, and can measure the electric field generated by the wake without destroying the generation and propagation of the wake. In addition, the main structure (array bracket) of the measurement system provided by the present invention is made of non-metallic materials, and the use of non-metallic materials can avoid the introduction of electromagnetic interference. In addition, the present invention also adopts the design of a switching device to place the electric field sensor in a tubular interface facing the required measurement direction. The fixing or installation method of the above electric field sensor can better avoid the shaking of the electric field sensor caused by the water flow, and further improve the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A schematic diagram of a ship propeller wake electric field testing system provided in Example 1 of the present invention;

[0022] Figure 2 A schematic diagram of the connection of a ship propeller wake electric field testing system provided in Example 1 of the present invention;

[0023] Figure 3 A side view of an electric field sensor array in a ship propeller wake electric field testing system provided in Example 1 of the present invention;

[0024] Figure 4 A top view of an electric field sensor array in a ship propeller wake electric field testing system provided in Example 1 of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of an array bracket in a ship propeller wake electric field testing system provided in Example 1 of the present invention.

[0026] Among them, 10-Ship propeller wake electric field test system;

[0027] 100-front-end sensing unit, 200-signal amplification and acquisition unit, 300-data transmission control unit, 400-host computer, 500-power supply unit;

[0028] 110-sensing module, 120-array bracket, 130-watertight cable, 140-suction cup;

[0029] 111-electric field sensor, 121-bracket, 122-adapter;

[0030] 210-weak signal amplification module, 220-signal conditioning module, 230-AD acquisition module, 240-FPGA control module;

[0031] 310-clock synchronization module, 320-multi-channel data processing module, 330-multi-channel data communication module;

[0032] 410 - data analysis and processing module, 420 - data communication module, 430 - display control module. DETAILED DESCRIPTION

[0033] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0034] Embodiment 1:

[0035] See also Figures 1 to 5Embodiment 1 provides a ship propeller wake electric field testing system 10, including: a front-end sensing unit 100, a signal amplification and acquisition unit 200, a data transmission control unit 300, a host computer 400 and a power supply unit 500.

[0036] Each unit is described below.

[0037] (1) Front-end sensing unit 100.

[0038] The front-end sensing unit 100 includes a sensing module 110 , and the sensing module 110 includes a plurality of electric field sensors 111 . The plurality of electric field sensors 111 are used to form a three-dimensional grid-type measurement network.

[0039] In general, the front-end sensing unit 100 is used to obtain the electric field signal of the ship propeller wake in three-dimensional space and transmit it to the signal amplification and collection unit 200 .

[0040] Among them, the front-end sensing unit 100 also includes an array bracket 120 and a watertight cable 130; the array bracket 120 includes a plurality of brackets 121, and a plurality of the brackets 121 are built to form an array structure, and a ship propeller wake channel is reserved; the electric field sensor 111 and the watertight cable 130 are both installed on the array bracket 120, the electric field sensor 111 is connected to the watertight cable 130, and the watertight cable 130 is connected to the signal amplification and acquisition unit 200.

[0041] Specifically, the watertight cable 130 may be buried inside the array bracket 120 .

[0042] In a preferred solution, the array support 120 may also include a plurality of adapters 122, which are mounted on the support 121. Each adapter 122 includes a plurality of tubular interfaces located within the same measurement point range and facing different measurement directions. An electric field sensor 111 is installed within the range of each measurement point, and the electric field sensor is placed in the tubular interface facing the desired measurement direction. For example, each adapter 122 is provided with four tubular interfaces, and the installation direction of the electric field sensor 111 can be adjusted according to different measurement directions. By adjusting the installation direction, the electric field signal at the point can be measured more stably, and the vector direction of the wake electric field can be measured.

[0043] The array bracket 120 is made of non-metallic material, and the non-metallic material may be PC polyethylene.

[0044] In addition, the front-end sensing unit 100 may further include a suction cup 140, which is used to adsorb the array bracket 120 to the wall and / or bottom of the test pool, so that the array bracket 120 can be flexibly adjusted according to the test conditions. The test pool can be an indoor salt water pool. According to application requirements, other auxiliary fixing devices can be used instead of the suction cup 140.

[0045] In application, all electric field signal transmission cables can be finally connected to a cabinet near the pool, and the signal amplification and acquisition unit 200, the data transmission control unit 300, the host computer 400 and the power supply unit 500 are installed in the cabinet.

[0046] In order not to destroy the wake channel, it is preferred to build a plurality of the brackets 121 to form a two-layer array structure, with 12 to 48 electric field sensors 111 arranged on each layer, the distance between two adjacent electric field sensors 111 on the same layer is 1m to 3m, and the distance between two adjacent electric field sensors 111 on different layers is 2m to 4m.

[0047] The electric field sensor 111 can use a dual carbon substrate Ag-rGO-CF composite electrode as a probe, with an electrode sensitivity of <1nV / m@1Hz and a self-noise of <1nV / Hz. 0.5 @1Hz, potential difference drift <40μV / 24h. Specifically, Ag is silver, rGO is reduced graphene oxide, CF is carbon fiber, and the dual-carbon substrate Ag-rGO-CF composite electrode has a honeycomb rGO conductive skeleton and Ag nanoparticles dispersed by a simple sealed oxidation process and a hydrothermal method. The above composite electrode can achieve high-precision measurement.

[0048] (2) Signal amplification and acquisition unit 200.

[0049] The signal amplification and acquisition unit 200 includes a weak signal amplification module 210 , a signal conditioning module 220 , an AD acquisition module 230 and an FPGA control module 240 .

[0050] In general, the signal amplification and acquisition unit 200 is used to amplify, condition and convert the received electric field signal into analog-to-digital signals and transmit the signals to the data transmission control unit 300. Specifically, the weak signal amplification module 210 is used to amplify the weak electric signal, the signal conditioning module 220 is used to condition the signal, such as filtering, the AD acquisition module 230 is used to perform analog-to-digital conversion, and the FPGA control module 240 is used for control.

[0051] (3) Data transmission control unit 300.

[0052] The data transmission control unit 300 includes a clock synchronization module 310. For example, the clock synchronization module 310 uses a nanosecond atomic clock as a synchronization clock. In addition, the data transmission control unit 300 also includes a multi-channel data processing module 320 and a multi-channel data communication module 330. The multi-channel data processing module 320 is used to process the multi-channel data from the signal amplification and acquisition unit 200, and the multi-channel data communication module 330 is used to realize data communication with the signal amplification and acquisition unit 200 and the host computer 400.

[0053] In general, the data transmission control unit 300 is used to transmit the synchronized data to the host computer 400 .

[0054] (4) Host computer 400.

[0055] The host computer 400 includes a data analysis and processing module 410 , a data communication module 420 and a display control module 430 .

[0056] In general, the host computer 400 is used to analyze, process and display the received data. Data processing includes filtering, Fourier transform and the like.

[0057] (5) Power supply unit 500.

[0058] The power supply unit 500 is mainly used to provide a low-noise stable power supply for the signal amplification and acquisition unit 200 and the data transmission control unit 300 .

[0059] The overall working principle of the ship propeller wake electric field testing system 10 provided in Example 1 is described below. Figure 2Taking the test system including 48 electric field sensors 111 as an example, the electric field sensors 111 are used to sense the potential of each position in the pool space; among them, a certain electric field sensor 111 is selected as the common negative electrode, which is equivalent to zero potential, and all other electric field sensors 111 are used as positive electrodes, and the measured value of the positive electrode is subtracted from the measured value of the common negative electrode to achieve measurement. The watertight cable 130 is used to transmit the electric signal sensed by the electric field sensor 111 to the signal amplification and acquisition unit 200; the signal amplification and acquisition unit 200 includes a total of 47 signal amplification and acquisition modules, which mainly include two functions: one is to amplify and condition the weak electric signal input by the electric field signal transmission cable (i.e., the watertight cable 130), and the other is to convert the amplified and conditioned analog signal into a digital signal through an AD acquisition circuit; the data transmission control unit 300 is used to transmit the data of the 47 signal amplification and acquisition modules to the host computer 400, and memory control and data communication control are performed during the transmission process; the host computer 400 is used to receive and process the electric field signal data transmitted by the data transmission control unit 300, store the data in real time, perform analysis and processing such as filtering and Fourier transform on the test data, and display the processing results in real time.

[0060] The ship propeller wake electric field test system provided in Example 1 is a three-dimensional grid test system for measuring the electric field of the ship propeller wake. The system adopts a multi-scale synchronous acquisition method to solve the difficulty of testing the wake electric field. It senses and collects the electric field signal of the ship propeller wake in three-dimensional space through multiple high-precision electric field sensors, thereby forming a three-dimensional electric field spatial distribution test grid, which is conducive to analyzing the distribution and propagation of the ship propeller wake electric field in three-dimensional space. Compared with the existing underwater electric field test system, it has the advantages of multi-scale three-dimensional space synchronous testing, multi-section electric field data synchronous acquisition, and high system measurement sensitivity.

[0061] Example 1 can accurately measure the spatial distribution of the propeller wake electric field in an indoor salt water pool, which can solve the problem of insufficient measurement profile and measurement accuracy of the spatial distribution of the propeller wake electric field, and fill the gap in the domestic measurement of the spatial distribution of the propeller wake electric field. Since the ship propeller wake electric field signal is an important physical field signal that can be detected remotely, the accurate measurement of the signal is conducive to verifying and correcting the mathematical model of the propeller wake electric field, and is conducive to in-depth basic research on the spatial distribution and propagation law of the propeller wake electric field. Example 1 uses multiple electric field sensors to form an array measurement system in a three-dimensional space, which can synchronously collect potential difference data of multiple scales, and can accurately measure the propeller wake electric field signal in a three-dimensional space. It can be used to verify the mathematical model of the propeller wake electric field and analyze the rotational speed, blade frequency and other related information of the propeller.

[0062] Embodiment 2:

[0063] Embodiment 2 provides a ship propeller wake electric field testing method, which is implemented by the ship propeller wake electric field testing system as described in Embodiment 1. The ship propeller wake electric field testing method mainly includes the following steps:

[0064] The electric field signal of the propeller wake of the ship in three-dimensional space is obtained by using the front-end sensing unit and transmitted to the signal amplification and acquisition unit;

[0065] The signal amplification and acquisition unit is used to amplify and condition the received electric field signal and perform analog-to-digital conversion, and then transmit the signal to the data transmission control unit;

[0066] Utilize the data transmission control unit to transmit the synchronized data to the host computer;

[0067] The host computer is used to analyze, process and display the received data to obtain ship propeller wake electric field test information.

[0068] Since the steps in the ship propeller wake electric field testing method provided in Example 2 correspond to the functions of each unit or device in the ship propeller wake electric field testing system provided in Example 1, Example 2 can be understood by referring to the description of Example 1, which will not be repeated here.

[0069] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A ship propeller wake electric field testing system, characterized in that: include: Front-end sensing unit, signal amplification and acquisition unit, data transmission control unit, host computer and power supply unit; The front-end sensing unit includes a sensing module, and the sensing module includes multiple electric field sensors, and a three-dimensional grid-type measurement network is formed by using multiple electric field sensors; the front-end sensing unit is used to obtain the electric field signal of the ship propeller wake in three-dimensional space, and transmit it to the signal amplification and acquisition unit; the signal amplification and acquisition unit is used to amplify, condition and convert the received electric field signal into analog-to-digital form, and then transmit it to the data transmission control unit; the data transmission control unit includes a clock synchronization module; the data transmission control unit is used to transmit the synchronized data to the host computer; the host computer is used to analyze, process and display the received data; the power supply unit is used to provide power to the signal amplification and acquisition unit and the data transmission control unit.

2. The ship propeller wake electric field testing system according to claim 1, characterized in that: The front-end sensing unit also includes an array bracket and a watertight cable; the array bracket includes a plurality of brackets, and a plurality of the brackets are constructed to form an array structure, and a ship propeller wake channel is reserved; the electric field sensor and the watertight cable are both installed on the array bracket, the electric field sensor is connected to the watertight cable, and the watertight cable is connected to the signal amplification and acquisition unit.

3. The ship propeller wake electric field testing system according to claim 2, characterized in that: The array bracket also includes a plurality of adapter devices, which are installed on the bracket. Each of the adapter devices includes a plurality of tubular interfaces located within the same measurement point range and facing different measurement directions. An electric field sensor is installed within the range of each measurement point, and the electric field sensor is placed in the tubular interface facing the required measurement direction.

4. The ship propeller wake electric field testing system according to claim 2, characterized in that: The array bracket is made of non-metallic material.

5. The ship propeller wake electric field testing system according to claim 2, characterized in that: A plurality of the brackets are constructed to form a two-layer array structure, with 12 to 48 electric field sensors arranged on each layer, the distance between two adjacent electric field sensors on the same layer is 1m to 3m, and the distance between two adjacent electric field sensors on different layers is 2m to 4m.

6. The ship propeller wake electric field testing system according to claim 2, characterized in that: The front-end sensing unit also includes a suction cup, which is used to adsorb the array bracket to the pool wall and / or pool bottom of the test water pool.

7. The ship propeller wake electric field testing system according to claim 1, characterized in that: The electric field sensor uses a dual-carbon substrate Ag-rGO-CF composite electrode as a probe, with an electrode sensitivity of <1nV / m@1Hz and a self-noise of <1nV / Hz 0.5 @1Hz, potential difference drift <40μV / 24h.

8. The ship propeller wake electric field testing system according to claim 1, characterized in that: The clock synchronization module uses a nanosecond atomic clock as a synchronization clock.

9. The ship propeller wake electric field testing system according to claim 1, characterized in that: The signal amplification and acquisition unit includes a weak signal amplification module, a signal conditioning module, an AD acquisition module and an FPGA control module; the data transmission control unit also includes a multi-channel data processing module and a multi-channel data communication module; the host computer includes a data analysis and processing module, a data communication module and a display control module.

10. A method for testing the electric field of a ship propeller wake, characterized in that: The ship propeller wake electric field testing system is implemented according to any one of claims 1 to 9, and the ship propeller wake electric field testing method comprises the following steps: The electric field signal of the propeller wake of the ship in three-dimensional space is obtained by using the front-end sensing unit and transmitted to the signal amplification and acquisition unit; The signal amplification and acquisition unit is used to amplify and condition the received electric field signal and perform analog-to-digital conversion, and then transmit the signal to the data transmission control unit; Utilize the data transmission control unit to transmit the synchronized data to the host computer; The host computer is used to analyze, process and display the received data to obtain ship propeller wake electric field test information.

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