360 results about "Cavitation" patented technology

The invention relates to the technical field of monitoring and early warning, and discloses an automatic monitoring and early warning method and system for a pump room. The method comprises the following steps: collecting hydraulic pulsation, cavitation acoustic emission and bearing temperature rise data through multiple sensors; a pump efficiency attenuation vector is obtained based on an environment adaptive algorithm optimization feature; predicting the health state of the equipment by using a hydraulic model; carrying out deep learning classification by adopting a fault propagation network; and four-stage grading early warning is realized by combining water inflow-pump efficiency coupling judgment. According to the method and the device, the technical problem that the gradual change fault and the multi-parameter coupling fault mode of the pump room equipment under the underground complex working condition cannot be accurately identified in the prior art is solved, and the accuracy of fault prediction and the timeliness of early warning of the underground drainage pump room are improved.

The invention provides a numerical calculation method for double-explosion-source underwater explosion impact cavitation loads, and belongs to the technical field of computer data processing-based explosion impact wave calculation, and the method comprises the following steps: solving a propagation process of far-field underwater double-explosion-source explosion impact waves in a two-dimensional acoustic flow field by using a local discontinuous Galerkin (LDG) method; and the cavitation characteristics of the flow field under the action of the double-explosion-source underwater explosion shock waves are researched. A flow field dynamic pressure result calculated by the method is compared with a result calculated by an acoustic finite element method. The result shows that the flow field dynamic pressure result calculated by the method is well matched with the calculation result data of the acoustic finite element method, and the effectiveness and the accuracy of the method are verified.

The invention discloses an underwater thruster permanent magnet propeller capable of reducing cavitation noise, and relates to the technical field of propellers, the underwater thruster permanent magnet propeller comprises a mounting plate, a propeller body and a fairing; mounting holes are formed in the mounting plate, the mounting plate is fixedly mounted on the underwater propeller through matching of bolts and the mounting holes, a main shaft is rotationally connected to the middle of one end face of the mounting plate, the fairing is fixedly connected to one end face of the mounting plate, and the propeller body is fixedly mounted at the end, away from the mounting plate, of the main shaft. The vibration reeds are installed on the inner wall of the flow guide cover, the vibration reeds can vibrate at a high speed through vortexes generated by the cavitation bubbles, and therefore the cavitation bubbles large in size are scattered into a larger number of small cavitation bubbles, the noise decibel generated by the larger number of small cavitation bubbles is lower than the noise decibel generated by the large cavitation bubbles when the larger number of small cavitation bubbles are broken, and the frequency is higher than the noise decibel generated by the large cavitation bubbles when the larger number of small cavitation bubbles are broken. Due to the fact that the wavelength of the high-frequency noise is short, the high-frequency noise is easy to absorb and scatter, one part of the high-frequency noise is directly absorbed by the flow guide cover, and the underwater environment can restrain propagation of the high-frequency noise.

The invention provides a calculation method for propagation of underwater explosion shock waves in a non-uniform acoustic flow field, and the method comprises the steps: simulating the propagation of the underwater explosion shock waves in a non-uniform fluid through an axial symmetry calculation model of an underwater explosion load in the non-uniform fluid based on a local discontinuous Galerkin method and a continuity condition; according to the method, a calculation model special for heterogeneous fluid is constructed, and continuous conditions are combined, so that the propagation process of underwater explosion shock waves in a heterogeneous flow field containing a sound velocity discontinuous interface and a sound velocity gradient is effectively simulated. According to the method, the influence of the sound velocity spring layer interface on the underwater explosion shock wave propagation path and the load peak value can be accurately analyzed, and more reliable underwater explosion load data are provided for the action of the submarine near the sound velocity spring layer. According to the invention, the influence of the flow field sound velocity gradient on the underwater explosion load and cavitation characteristics can be effectively studied, and the design and construction scheme of the protection ship and maritime work structure is optimized according to more accurate underwater explosion load input data.

The invention relates to the technical field of ball valves, provides an intelligent sensing modular ball valve and a control method, and designs a valve body module and a control module. The valve body module is integrated with a multi-mode sensor, comprises a spirally-distributed acoustic sensor array, a physical quantity sensor group and a valve element state detection sensor, and monitors fluid acoustic characteristics, pressure, temperature, flow, liquid level and valve element displacement and torque in real time. The control module analyzes sensor data through a data fusion algorithm, and early identification of cavitation faults and detection of micro-crack faults are achieved. The system adopts an 8-bit dynamic coding mechanism to accurately position the fault type, and adjusts the opening or torque of the actuator in a linkage manner. The method has multi-parameter cooperative sensing, early fault early warning and self-adaptive control capabilities, and the reliability and safety of the ball valve under complex working conditions are remarkably improved.

The invention discloses a slurry circulating pump state monitoring method and related equipment, and aims to overcome the defects of high false alarm rate and late early warning caused by multi-fault coupling effect and strong background noise interference in the prior art. The method comprises the following steps: synchronously acquiring vibration, acoustic emission, pressure pulsation and temperature signals of a pump volute, an outlet pipeline and a bearing seat; performing wavelet packet decomposition on the acoustic emission signals, extracting features and generating cavitation sensitive factors; a digital twinborn model adapted to fluid-structure coupling simulation and transfer learning is utilized to calculate a deviation value between the monitoring feature and a normal baseline; and when the deviation value exceeds a threshold value, fault identification and life prediction are carried out. Through multi-signal fusion and a dynamic threshold mechanism, a multi-fault coupling effect and strong background noise interference are effectively overcome, and the reliability of a monitoring system is improved.

The invention discloses an experiment table and an experiment method capable of identifying cavitation of a vane pump, and belongs to the technical field of vane pump cavitation characteristic identification experiments. The experiment table comprises a test pump to be tested, a flowmeter, a loudspeaker, a flow adjusting valve and six pressure sensors; the flow meter is arranged on a water outlet pipeline of a to-be-tested test pump and is used for measuring the flow of the water outlet pipeline of the pump; the loudspeaker is arranged on a water inlet pipeline of a test pump to be tested, and when the loudspeaker serves as an external sound source, the loudspeaker can radiate sound pressure waves with different acoustic loads into the water inlet pipeline by adjusting the frequency and strength of the acoustic loads of the loudspeaker. The flow regulating valve is arranged on a water outlet pipeline of the test pump to be tested and is used for regulating the flow of the pump system; the six pressure sensors are data acquisition elements for monitoring cavitation noise of the to-be-tested test pump, and three pressure sensors are respectively arranged on a water inlet pipeline and a water outlet pipeline of the to-be-tested test pump and are used for monitoring sound pressure signals.

The invention discloses a composite multi-frequency marine ultrasonic anti-fouling system and method, relates to the technical field of marine anti-fouling, and aims to change a single-frequency or simple-pulse ultrasonic transmitting mode, transmit composite multi-frequency ultrasonic waves in a wide frequency band, and superpose the ultrasonic waves of multiple frequencies in a transmission medium to generate a cavitation effect so as to achieve the anti-fouling effect. The method is used for avoiding the tolerance of marine organisms, improving the anti-adhesion efficiency and enhancing the effect of a specific area; the wave generating frequency and the working frequency are dynamically adjusted according to the running state and the environment condition of the ship, the energy consumption and the biological adhesion rate of the ship are reduced, and the relation among the biological adhesion rate, low energy consumption and the environment protection requirement is balanced.

The utility model provides an outdoor Bluetooth sound equipment with good waterproof effect, which relates to the technical field of Bluetooth sound equipment and comprises a shell and a sound box mechanism, a partition plate is fixedly connected inside the shell, and the sound box mechanism is arranged on the inner side of the shell. Through the arrangement of the sound box mechanism, a battery can be charged without using a charging interface through the wireless charging coil, the integrity of the shell is protected, and through the arrangement of the loudspeaker assembly, the waterproof sound transmission film prevents water from permeating into the loudspeaker and does not affect the quality of sound played by the loudspeaker at the same time. The protection cover can protect the waterproof sound transmission film from being damaged by sharp objects, the sealing performance of the waterproof sound transmission film is protected, through the arrangement of the waterproof assembly, the cavitation column can float upwards when the equipment is completely immersed in liquid, one side of the loudspeaker assembly is made to float on the water surface, and water leakage caused by the fact that the sealing performance of the equipment is damaged by water pressure in the deep position of the liquid is prevented. The sealing ring can further prevent liquid from permeating into the equipment, and the waterproof performance is further improved.

The invention discloses a simulation method for a corresponding relation between a baffle tongue position and a flow field of a semi-spiral suction chamber, and relates to the technical field of double suction pump design and numerical simulation. According to the method, a three-dimensional flow channel model of multiple groups of baffle tongue reference position parameters is constructed, multi-working-condition simulation and quantitative analysis are combined, a mapping relation model of baffle tongue positions and flow field characteristic parameters is established, and a baffle tongue region vortex generation rule, turbulence dissipation and pressure pulsation characteristics are accurately captured; the optimal baffle tongue parameter interval is determined by combining the flow field uniformity and energy loss minimization principle, the flow loss is effectively reduced, the vortex strength and energy dissipation are reduced, and the flow field uniformity is improved, so that the pump efficiency is improved, the vibration noise and the cavitation phenomenon are inhibited, and the optimal baffle tongue parameter interval is obtained by adopting adaptive grid encryption, a multiphase flow cavitation model and a test verification mechanism. The mapping model is corrected by combining measured data, so that the optimization result can directly guide the baffle tongue design under different working conditions, the research and development period is remarkably shortened, and the physical test cost is reduced.

The invention relates to an ultrasonic atomization pulse type cold air jet cooling and lubricating device and an operation process thereof. The device comprises an air compressor, a cold air generator, a gas storage tank, a pulse control valve and an ultrasonic atomization nozzle module which are sequentially connected through a gas pipeline. The ultrasonic atomizing nozzle module comprises an ultrasonic transducer, a stepped amplitude-variable rod, a waterproof cover, a sealing cover and a focusing nozzle. In the working process, the stepped amplitude-variable rod amplifies the high-frequency mechanical vibration amplitude of the ultrasonic transducer, and cutting fluid is efficiently atomized into micron-sized liquid drops through the cavitation effect and the capillary wave effect; meanwhile, the cold air generator converts high-pressure air provided by the air compressor into low-temperature gas and temporarily stores the low-temperature gas in the gas storage tank, and the low-temperature gas is released in a pulse mode through the precise pulse control valve according to the set frequency and duty ratio. The pulse low-temperature gas enters the sealing cover to be fully mixed with the atomized liquid drops, uniform gas-liquid two-phase jet flow is formed, finally, the jet flow is accelerated by the focusing nozzle to form high-speed convergent jet flow, the high-speed convergent jet flow acts on a cutting area accurately, and pulse type efficient cooling and lubricating cutting machining is achieved.

The invention discloses a multi-stage coupling jet enhanced shear mixing aeration system and an application method thereof. The aeration system comprises an air inlet section, a liquid inlet section, a bubble generator connected to the common downstream of the air inlet section and the liquid inlet section, and a regulating valve and an aeration tank which are sequentially connected to the downstream of the bubble generator, the bubble generator sequentially comprises a gas-liquid mixing unit, a rotational flow shearing unit, a turbulence strengthening unit and an oscillation self-excitation unit from upstream to downstream; according to the invention, negative pressure air suction, vortex shearing, hydrodynamic cavitation effect and the like are integrated in a device without a moving part; the gas-liquid mixture is crushed into nanoscale bubbles at the tail end turbulence section; the method has the remarkable advantages of lower energy consumption, higher bubble nucleation rate, smaller particle size and more uniform distribution. In addition, due to the unique multi-flow-field coupling design, adaptability to different water qualities is higher, and stable and efficient nanobubble generation capacity can be kept under wider working conditions.

The invention relates to the technical field of wave concentrators, and discloses a cavitation wave concentrator which comprises a connecting pipe, one end of the connecting pipe is fixedly connected with an adjusting pipeline, one end of the adjusting pipeline is fixedly connected with a cavitation generator, water flow is conveyed from the A direction to the B direction in a resonant cavity, and the water flow is conveyed in the cavitation generator. Water flow is accelerated and local pressure is reduced through the cavitation generation pipe, so that bubbles are induced to be formed and tiny bubbles are manufactured, pressure waves generated by the resonant cavity are spread in fluid in the form of sound waves and are finally reflected and focused through the arc-shaped wave gathering opening, a high-pressure, high-temperature and high-energy gathering area is generated, and the bubbles fully grow up in the area. Grown bubbles are rapidly annihilated when encountering microorganisms through water jet, so that huge impact force and shear force are generated, and barnacles at the bottom of the ship are efficiently washed away in water. According to the device, efficient impact force is achieved through the pressure wave gathering effect and the cavitation effect, then barnacles and other attachments at the bottom of the ship can be easily removed, and the effect is better.

The invention provides a fluid critical heat flux prediction method and device, equipment and a storage medium. The method comprises the steps that a first simulation model of the in-channel boiling heat transfer process of a target channel is acquired; a plurality of heat flow densities are sequentially input into the first simulation model, and the maximum wall surface superheat degree and the maximum wall surface void fraction corresponding to each heat flow density are obtained; the heat flow density with the change rate of the corresponding maximum wall surface superheat degree larger than or equal to a first threshold value in the multiple heat flow densities is determined as the first heat flow density; comparing a wall surface maximum void fraction corresponding to the first heat flux with a wall surface boundary void fraction; and under the condition that the wall surface maximum void fraction corresponding to the first heat flow density is larger than or equal to the wall surface boundary void fraction, the critical heat flow density is determined according to the first heat flow density. According to the prediction method for the critical heat flux of the fluid, efficient and accurate prediction of the critical heat flux can be realized.

The invention belongs to the technical field of mechanical equipment fault detection and diagnosis, and particularly relates to a centrifugal pump multi-sensor data fusion cavitation monitoring and early warning system. The data acquisition unit comprises an acoustic emission sensor, a vibration sensor, a pressure sensor, a power monitoring sensor and a noise sensor and is used for monitoring different characteristics of a cavitation phenomenon; the signal preprocessing unit is used for preprocessing signals acquired by various sensors; the data fusion unit is used for recognizing typical characteristics of cavitation by combining a fluid mechanics model, a power consumption model and signals acquired by the sensor in real time; multi-sensor signal fusion and sound field, vibration field and fluid dynamic field coupling analysis are adopted; the two-way data analysis and operation state feedback unit comprises a real-time feedback mechanism and a reverse feedback mechanism, operation parameters are dynamically adjusted by monitoring operation data of the pump in real time, and the working state of the pump is optimized. According to the invention, the accuracy and real-time performance of cavitation monitoring are effectively improved.

The invention relates to the technical field of cavitation jet equipment, in particular to a multifunctional cavitation jet test device, which comprises a mounting frame; the circulating water tunnel main body is mounted on the mounting frame, a water tunnel space is formed in the circulating water tunnel main body, and an observation window is formed in the circulating water tunnel main body; the circulating unit is connected to the mounting frame, is connected with the circulating water tunnel main body and is used for changing the liquid flow rate and the liquid pressure in the water tunnel space; the cavitation nozzle is connected with the circulating water tunnel main body and located in the water tunnel space, and cavitation jet flow emitted by the cavitation nozzle is located in an interval right opposite to the observation window; the device has the advantages that the high-speed camera can conveniently shoot and record the cavitation formation, development and collapse process of the cavitation jet flow in different liquid flow states through the observation window, the cavitation jet flow can be conveniently emitted through the cavitation nozzle, and the circulating water tunnel main body and the circulating unit are matched to complete the research on the influence of the flow field characteristics on the cavitation jet flow action mechanism.

The invention relates to the technical field of pumped storage power stations, and discloses a pumped storage power station transient safety monitoring method, a pumped storage power station transient safety monitoring device, a storage medium and a product. The requirement of real-time simulation in the transient process is met; the cavitation volume fraction is obtained through three-dimensional simulation, and the influence of the volume of gas generated by cavitation on the compressibility of the water body is determined. Further, the influence degree of working condition parameters on the wave velocity is determined in combination with sensitivity analysis, and physical mapping logic is provided for a wave velocity prediction model; and a high-precision mapping model of the working condition parameters and the wave velocity is constructed by utilizing a machine learning algorithm, so that rapid prediction of the wave velocity is realized, the calculated amount of traditional cross-scale simulation is reduced, and the real-time performance is improved. Furthermore, when cavitation occurs, dynamic monitoring of transient safety of the pumped storage power station is realized through fusion of the wave velocity prediction model and one-dimensional transient simulation.

A system and method for determining fluid quality or change in quality by training machine learning algorithms using ultrasound Fast Fourier Transform (FFT) signatures. The system includes one or more ultrasonic transducers embedded inside or outside of a pipe, piping, or vessel that allows a fluid to flow past or between the ultrasound transducers. The transducer's acoustic energy creates ultrasound pressure waves and localized heat due to acoustic cavitation. The cavitation creates bubbles that collapse creating ultrasound sonic energy in the time domain. Unique sonic time-domain signatures, distinctively associated with the characteristics of the fluids, are converted to FFTs to produce unique, well-defined frequency response signatures. Machine learning algorithms are used to identify, measure, and classify the unique frequency response signatures associated with a wide range of fluids.

The invention relates to a pressure static calibration method based on cavitation collapse and an R-P equation. In order to solve the problem of calibration result deviation caused by a traditional static calibration method of a high-dynamic-performance pressure sensor, the method provided by the invention takes transient pressure shock waves released in a cavitation collapse process as an excitation source, and the pulse width of the pressure shock waves released in the process is about 1 microsecond; the frequency band blank of microsecond-level static calibration is filled, a first-time cavitation collapse pressure peak value obtained through calculation in combination with a Rayleigh-Plesset equation and a dissipation formula of pressure shock waves in liquid is compared with a first-time cavitation collapse pressure peak value received by a pressure sensor, a pressure peak value difference value at the moment is obtained and serves as a peak value compensation error of the pressure sensor, and the frequency band compensation error of the microsecond-level static calibration is calculated. And completing calibration.

The utility model discloses an oblique radiation ultrasonic beriberi symptom treatment device which comprises a container containing cavitation liquid, at least one group of ultrasonic transducers are installed outside the container in an oblique upward sound wave irradiation mode, and feet placed in the container are cleaned and nursed by utilizing the cavitation effect of ultrasonic waves in water. According to the beriberi symptom treatment device with the oblique radiation ultrasonic waves, the ultrasonic transducer assemblies are installed in an oblique upward sound wave irradiation mode, the sound wave superposition principle and the change of the sound propagation direction are utilized, a standing wave non-uniform sound field is avoided, the cavitation effect of the sound field is further enhanced in different areas, and therefore cleaning, sterilization and massage strengthening on the feet are achieved.

The utility model discloses a multi-layer flow channel necking-down type ball valve, relates to the technical field of ball valves, and solves the problems that high-pressure fluid scours a sealing surface and is cavitated due to the fact that a conventional flow channel outlet shape cannot effectively rectify and depressurize fluid. A sleeve is installed in the flow channel, the sleeve and the flow channel are coaxially arranged, the sleeve extends to the outlet position from the inlet position of the flow channel, and the sleeve is fixedly connected to the inner wall of the flow channel. The outlet position of the flow channel and the outlet of the sleeve are in a necking shape with the inner diameter gradually reduced. The sleeve divides the flow channel into multiple layers, layered flowing of fluid can be achieved, mutual interference among the fluid is reduced, the turbulent flow generation probability is reduced, and impact abrasion of the fluid to a sealing face is relieved. The necking shape accelerates the fluid through the Venturi effect, can rectify and depressurize the fluid, optimizes the flowing state of the fluid, balances the pressure of inner and outer flow channels of the sleeve and inhibits the cavitation phenomenon, the fluid impact is closer to the center of the flow channel, the turbulence intensity at an outlet is reduced, and the direct impact on the sealing surface of the valve seat is reduced.

The utility model relates to a high-pressure-drop regulating valve internal part structure, and belongs to the technical field of fluid control. The high-pressure-drop regulating valve internal part structure comprises a valve body, a first cavity and a second cavity, wherein the first cavity and the second cavity are arranged in the valve body; the first cavity comprises an assembly reserved cavity and a medium circulation cavity, a first through hole is formed between the lower end of the assembly reserved cavity and the second cavity, a valve seat, a lamination assembly and a sleeve are sequentially connected in an abutting mode from the cavity bottom to the cavity opening of the assembly reserved cavity, and a through-flow groove and a through-flow hole are formed in the lower end of the sleeve; according to the utility model, a high-pressure-difference fluid is subjected to primary pressure reduction through the through-flow grooves and the through-flow holes in the sleeve, and the fluid is subjected to pressure reduction when passing through each lamination through the lamination assembly formed by the plurality of laminations, so that the cavitation phenomenon generated when the high-pressure-difference fluid flows through the valve is greatly reduced, the noise generated by vibration is reduced, and the service life of the valve is prolonged. Good dynamic stability of the valve in operation is guaranteed, and the service life of the valve is prolonged.

The invention discloses a multi-angle cavitation water jet ice breaking experimental device and method in an immersion state, and relates to the technical field of ice breaking devices.The multi-angle cavitation water jet ice breaking experimental device comprises a water tank supporting frame, a transparent water tank and a jet control mechanism are arranged in the water tank supporting frame, and the jet control mechanism is installed at the bottom of the transparent water tank and comprises an adjusting assembly and a nozzle assembly; the test piece impact assembly is used for impacting the fixed test piece and comprises a supporting assembly and a clamping assembly; the pressure output assembly comprises a high-pressure pump set, a high-pressure electromagnetic valve, a constant-pressure tank and a high-pressure pipe for connecting all the parts; the device can complete a cavitation jet ice breaking test in an immersion state, the nozzle can realize vertical movement and multi-angle jet operation through the position adjusting assembly, and experiment requirements of different jet target distances and different jet inclination angles can be met at the same time; linkage operation of the high-pressure electromagnetic valve and the high-pressure pump set can be achieved through computer control, and the testing effect is guaranteed.

The utility model discloses a material testing device under erosion and cavitation coupling action, which comprises a container, an ultrasonic transducer, an injector head and a circulating device, a placing table is arranged in the container, the ultrasonic transducer is used for being arranged above the placing table, the injector head is arranged at the lower end of the ultrasonic transducer, and the circulating device is arranged on the placing table. The circulating device comprises a booster pump, a liquid inlet of the booster pump is communicated with the container, and a liquid outlet of the booster pump is connected with the injector head through a pipeline; in the using state, the ultrasonic transducer is electrically connected with an ultrasonic power source through a wire. According to the utility model, the erosion medium is pumped into the injector head through the booster pump, and meanwhile, the ultrasonic transducer enables the erosion medium to generate a large number of bubbles in the injector head, so that the erosion medium with the bubbles impacts a test material at a high speed, and the test condition of the hydraulic mechanical material is met.

The invention provides a method for measuring cavitation collapse pressure and a Y-shaped optical fiber probe device thereof, and belongs to the field of cavitation collapse pressure measurement in multiphase flow. The method for measuring the cavitation collapse pressure mainly comprises the following steps of: 1, decomposing a voltage to be measured into an average direct current component voltage and an average alternating current component voltage; 2, obtaining the relation between the measured voltage and the liquid refractive index through the relation between the measured voltage and the liquid refractive index; and step 3, obtaining a group of liquid densities according to the relationship between the measured voltage and the liquid refractive index, finally obtaining the relationship between the cavitation collapse pressure in the to-be-measured liquid and the liquid density by combining a Tit equation or looking up an IAPWS table, and further obtaining the relationship between the measured voltage and the pressure generated by cavitation collapse in the to-be-measured liquid. According to the method, the pressure generated by cavitation collapse can be measured simply, efficiently and at high frequency.

The utility model discloses a flow regime adjusting device for heavy sediment, which belongs to the technical field of building material stirring, and comprises a tank body and a tank cover arranged at the top of the tank body, a barrel body with a closed top end and an open bottom end is arranged on the inner side of the tank body, and a plurality of flow regime adjusting devices are arranged on the inner side of the barrel body. A feeding port and a discharging port are formed in the side wall of the bottom end and the side wall of the top end of the barrel respectively, a driving motor is installed on the upper surface of the tank cover, and the power output end of the driving motor is in transmission connection with a shaft rod extending to the inner side of the barrel. Meanwhile, small bubbles are formed in the liquid under the cavitation action of ultrasonic waves, and the bubbles expand and contract under the action of sound waves and finally collapse severely under high pressure to generate strong shearing force and shock waves, so that the materials are effectively mixed.

The invention relates to the technical field of spectral analysis, and particularly discloses an underwater intelligent detection machine system and method based on laser-induced breakdown spectroscopy, and the system comprises an underwater carrying platform, an orthogonal double-pulse laser-induced breakdown spectroscopy probe, a multi-sensor cooperative sensing module, a mechanical arm, a central control unit and a water surface control station. The method comprises the following steps: a first pulse vertically builds bubbles, and a second pulse parallelly enters the bubbles and is triggered according to delay time; the central control unit maintains a working distance of 1-2cm based on a distance measurement closed loop, and adaptively adjusts delay time and energy in combination with water depth pressure and cavitation feedback; and the water surface control station carries out denoising normalization on the spectrum calibration and carries out element qualitative and quantitative operation to generate an element distribution atlas. According to the method, plasma is excited in a cavitation bubble gas environment through orthogonal double pulses, and in-situ real-time high-sensitivity element detection of an underwater target is realized in combination with distance closed loop and parameter self-adaption.

The invention relates to the technical field of cavitation monitoring, in particular to a tidal current energy water turbine cavitation predicting and monitoring method which comprises the steps that S1, multi-sensor data of a tidal current energy water turbine are collected, and the multi-sensor data comprise vibration signals, ultrasonic signals and pressure signals; s2, performing frequency domain analysis on the vibration signal, and extracting an energy value of a high frequency band as a vibration characteristic value; s3, performing transmission attenuation analysis on the ultrasonic signal, and calculating an ultrasonic attenuation rate as an ultrasonic characteristic value; s4, performing frequency domain analysis on the pressure signal, and extracting a pressure pulsation amplitude at a blade passing frequency as a pressure characteristic value; s5, based on the vibration characteristic value, the ultrasonic characteristic value and the pressure characteristic value, the current cavitation state is determined through a cavitation state judgment rule; and S6, predicting the evolution trend of the cavitation state, and estimating the residual safe operation time of the water turbine under the current working condition. The cavitation recognition result is converted into a quantitative life index, and the method has engineering application value and safety guarantee capability.

The utility model relates to the technical field of cleaning equipment, in particular to a cleaning tool for cleaning miniature blind holes, which is provided with a supporting cavity, a top plate is arranged above the supporting cavity, a liquid inlet is formed in the supporting cavity, a liquid outlet pipe is arranged on the supporting cavity, the liquid outlet pipe is communicated with the supporting cavity, and supporting fins are arranged on the side wall of the liquid outlet pipe. Cleaning liquid is jetted into the blind hole of the part through the liquid outlet pipe, as the cleaning tool is completely immersed in the water tank of the ultrasonic cleaning machine, ultrasonic waves can directly act on the surface of the part and the interior of the blind hole, and the jetted cleaning liquid can directly wash dirt and impurities in the blind hole of the part, disperse bubbles and break a bubble barrier; the effective permeation and cleaning effect of cleaning liquid are ensured, ultrasonic cleaning can go deep into the fine and tiny positions of the blind hole, a dirt layer is dispersed, emulsified and stripped off through the cavitation effect and the acceleration effect, the dual functions of liquid jet flushing and ultrasonic cleaning are achieved, and the cleaning efficiency and quality are remarkably improved.

The invention discloses a two-dimensional near-free-surface underwater explosion cavitation forecasting method, and relates to the technical field of explosion.The method comprises the steps that a mixed fluid is regarded as a mixture of multiple fluid media, and a multiphase compressible fluid motion control equation related to state parameters of the mixed fluid before the mixed fluid reaches an equilibrium state and the mass fraction of the fluid media of all phases is constructed; then constructing a thermodynamic state equation of any k-phase fluid medium based on an NASG equation, and constructing a cavitation phase change equation after the mixed fluid completes phase change relaxation to reach an equilibrium state by considering the phase change process of a liquid phase and a steam phase when a flow field changes; and solving an equation set formed by a multiphase compressible fluid motion control equation, a thermodynamic state equation of each phase of fluid medium and a cavitation phase change equation in each cycle step to obtain a numerical forecasting result. According to the method, cavitation is regarded as the continuous accumulation process of the steam phase content in the mixed fluid, the physical essence is better met, and therefore the forecasting result is more accurate.