22 results about "Flow resistivity" patented technology

The invention discloses a self-adaptive grouting control plugging method based on mining-induced fracture real-time monitoring, and relates to the technical field of mine safety engineering and hydrogeology. Through cooperative work of the grouting mechanism, the data monitoring system, the data collecting and processing module and the self-adaptive control module, automation and intellectualization of grouting protection can be achieved, and through introduction of the fracture roughness coefficient and the time-dependent viscosity, rough fracture flow resistance and grout rheology and time-varying characteristics are quantified, and the grout diffusion radius calculation error is reduced. The data weight is dynamically adjusted through a micro-seismic travel time residual error and sound wave velocity field joint inversion algorithm in combination with a weighted robust LM algorithm, and accurate fracture positioning is achieved. And a PID gain compensation and saturation function mechanism is adopted, so that self-adaptive safe and efficient grouting is realized. The fracture dynamic state is monitored in real time through the multi-source data fusion technology, grouting parameters are dynamically optimized in combination with an intelligent algorithm, complex geological interference is effectively restrained, slurry waste is reduced, and efficient and accurate plugging of mining-induced fractures is achieved.

The invention belongs to the technical field of microcosmic interface dynamic research, and relates to a method and system for predicting the imbibition behavior of a microcosmic two-phase interface of a porous medium, and the method comprises the steps: obtaining a pore network composed of pores and throats according to a target porous medium; calculating the flow of the two-phase fluid injected into the throat; according to the flow of the two-phase fluid injected into the throat, the flow of the fluid in the main interface displacement mode and the flow of the fluid in the wetting mode displacement mode are calculated; determining the displacement mode of the two-phase fluid interface according to the fluid flow ratio under the two displacement modes; according to the displacement mode of the two-phase fluid interface, the flow resistance corresponding to the throat is calculated; according to the flow resistance, a motion control equation of the two-phase fluid is updated, and therefore prediction of the imbibition behavior of the micro two-phase interface of the porous medium is completed. According to the method, the preferential flow paths and the dynamic evolution modes of different types of interfaces in the displacement process in the pore structure of the complex porous medium are defined, and the types of the fluid interfaces are accurately judged under the transient condition.

The invention provides a resonant cavity air suction silencer and a compressor, relates to the field of compressors, and aims to solve the problem that an existing air suction silencer is difficult to balance high sound transmission loss and low pressure loss, the resonant cavity air suction silencer is divided into three cavities through a first baffle and a second baffle in a shell, a bent flow guide pipe is installed in the shell, and three resonant holes are formed in the flow guide pipe; the openings of the two sections of channels at the position of the resonance hole face each other, the resonance hole and the cavity form a resonance structure, when noise sound waves transmitted from the air inlet pass through the resonance hole, sound wave energy triggers resonance in the cavity, so that noise energy is attenuated due to resonance dissipation, the noise is repeatedly dissipated on a propagation path through the three-stage resonance effect, high sound transmission loss is achieved, and the noise loss is reduced. The first end is opposite to the air inlet, the second end is opposite to the air outlet, and the opposite opening of the flow guide pipe reduces gas impact and turbulence, reduces flow resistance, realizes low pressure loss, and further balances sound transmission loss and pressure loss.

The invention relates to the technical field of reactor safety analysis, and provides a pressurized water reactor pressure vessel lower chamber flow distribution analysis method. The method comprises the following steps: establishing a fluid domain three-dimensional geometric model; performing unstructured grid division on the fluid domain three-dimensional geometric model to generate a three-dimensional calculation grid; selecting a turbulence model; setting inlet boundary conditions and physical property parameters of the coolant; the reactor core area is equivalent to a porous medium area, and flow resistance parameters of the porous medium area are set; based on the three-dimensional calculation grid, adopting a selected turbulence model, loading flow resistance parameters of a porous medium area and inlet boundary conditions and physical property parameters of a coolant, and carrying out three-dimensional flow simulation to obtain coolant flow distribution at the section of a reactor core inlet; and evaluating the flow distribution uniformity of the reactor core inlet according to a preset flow distribution evaluation criterion. The method is used for simulating three-dimensional flow of a coolant in a lower cavity of a reactor pressure vessel, acquiring a flow field structure and flow distribution data of the coolant, and performing quantitative evaluation.

The application discloses a center exhaust bending disc transducer dense array and method for depth-keeping air pressure compensation, which comprises a plurality of up-and-down arranged bending disc transducer array elements, each of which comprises an outer frame, a radiation panel, a water-tight adhesive layer, a piezoelectric ceramic, a center joint and a bottom end joint, a plurality of same bending disc transducer array elements are connected through Kevlar ropes at multiple points, and air paths between adjacent bending disc transducer array elements are connected in series through the center joint and an air pipe, the bottom of the bending disc transducer array element is provided with a protection box connected out through the bottom end joint, so as to prevent seawater from flowing back. The application can collect water through the shape of the array element radiation panel, reduce the use of the length of the air pipe through the center drainage mode, reduce the air flow resistance, accelerate the efficiency of the transducer drainage and inflation link, improve the safety, has small changes on the transducer structure and performance, is relatively controllable, and has low cost.

The invention discloses a superstructure device optimization method and equipment giving consideration to ventilation and noise reduction and a storage medium, and relates to the field of acoustics. According to the superstructure device optimization method and equipment giving consideration to ventilation and noise reduction and the storage medium, a superstructure device giving consideration to ventilation and noise reduction performance is designed, an agent model reflecting the relation between structure parameters of the superstructure device and flow resistance and noise reduction performance is constructed, and a sequence optimization strategy is established; the superstructure device considering ventilation and noise reduction performance is designed according to the proxy model and the sequential optimization strategy, and the structure parameters of the superstructure device can be optimized to reduce the flow resistance on the basis of improving the noise reduction performance so as to optimize the ventilation performance.

The application discloses a kind of multistage distributed cold traps based on lunar surface environment, including arch shell, the inner surface of arch shell is pasted with sealing film, several cold trap units are installed in the inner surface of arch shell and are distributed in array;The cold trap unit includes framework, the outer side of framework is attached with sealing film, the inner side of framework is cold trap entrance and is pasted with selective permeation membrane with molecular sieve effect, the bottom surface of framework is fixedly provided with microcapsule phase change layer, and porous medium made of high thermal conductivity material is embedded in the inside of framework;The porous medium is arranged in the inside of framework with gradual porosity or with gradient porosity.The application not only reduces vapor flow resistance and enhances surface desublimation active site density, but also realizes space matching of heat flow density and vapor flux, improves energy quality transfer synergistic efficiency, and can also buffer external radiation fluctuation, so as to maintain long-term stability of temperature inside cold trap.

The invention relates to a porous material flow resistivity measuring method and system.The method comprises the steps that when the rear surface of a to-be-measured sample is tightly attached to the rigid wall of an impedance tube, the first acoustic impedance rate of the front surface of the to-be-measured sample is obtained through measurement; when the distance between the rear surface of the to-be-measured sample and the rigid wall of the impedance tube is L, measuring to obtain a second acoustic impedance rate of the front surface of the to-be-measured sample; deriving the characteristic acoustic impedance of the to-be-tested sample according to the first acoustic impedance rate, and deriving the rear surface acoustic impedance rate of the to-be-tested sample according to the second acoustic impedance rate; based on the first acoustic impedance rate, the second acoustic impedance rate, the characteristic acoustic impedance of the to-be-detected sample and the rear surface acoustic impedance rate of the to-be-detected sample, the wave number of sound propagating in the to-be-detected sample is solved; and calculating the flow resistance rate of the to-be-detected sample according to the wave number of the sound propagating in the to-be-detected sample and the characteristic acoustic impedance of the to-be-detected sample. The method for measuring the flow resistivity of the porous material can remarkably reduce the measurement cost and the measurement complexity.

The invention belongs to the related technical field of heat sinks, and discloses a fixed wall temperature design method for a porous heat sink, which comprises the following steps: S1, constructing a physical model of the heat sink, determining related parameters of the heat sink, a coolant and a porous medium, and setting a designed wall temperature according to a maximum allowable temperature or an expected temperature; s2, ideal local Nusselt number distribution in the flowing direction of the coolant is solved and obtained; s3, establishing the correlation between the local Nusselt number of the heat sink in the coolant flowing direction under the designed wall temperature condition and a to-be-designed structure parameter, and obtaining a corresponding function relationship; and S4, solving to obtain continuous function distribution of the to-be-designed structure parameters along the flowing direction. According to the method, under the constraint of the given wall surface maximum temperature, the porosity or the function distribution of the filling porous cross-sectional area in the flowing direction can be obtained, so that the flowing resistance is remarkably reduced, the wall surface temperature uniformity is improved, and the power and the thermal stress of the pump are effectively reduced.

In some embodiments according to the present disclosure, methods for mitigating particle retention are provided including the use of frequency sweep excitation to eject particle in the sweep. In some embodiments according to the present disclosure, the acoustically driven fluid ejector can be capable of being switched between multiple modes of operation. In other embodiments according to the present disclosure, the acoustically driven fluid ejector can be altered such that it includes the capability to be filled with a biocompatible material to aid in the mitigation of particle aggregation in the acoustically driven fluid ejector. In some embodiments according to the present disclosure, the solid structure and number of nozzles of the acoustically driven fluid ejector can be adjusted such that the ejector of the acoustically driven fluid ejector can be self-pumping, i.e. no external pumping mechanism other than acoustics driven flow drag is used.

This invention discloses a perforated plate sound-absorbing structure with adjustable equivalent surface acoustic impedance (ESI). It includes a perforated panel, a cavity on the back of the panel, and a flexible sound-absorbing layer within the cavity. The flexible sound-absorbing layer is parallel to and always covers the back of the perforated panel. The flexible sound-absorbing layer has different flow resistivity distributions in different regions along its length. The flexible sound-absorbing layer is connected to a roller assembly to drive it to translate along its length. By aligning the different flow resistivity regions of the flexible sound-absorbing layer with the back of the perforated panel, the equivalent surface acoustic impedance of the perforated plate sound-absorbing structure can be adjusted. This solution achieves continuous and precise adjustment of the equivalent surface acoustic impedance by translating the flexible sound-absorbing layer, which always covers the back of the perforated panel and has a gradient or segmented flow resistivity distribution, thereby changing the corresponding positions of different flow resistivity regions on the back of the perforated panel. The adjustment accuracy is high, and it can meet the impedance matching requirements at different frequencies.

The invention discloses a low-resistance acoustic lining panel with elliptical holes and a design method thereof, the low-resistance acoustic lining panel comprises a perforated plate, a plurality of uniformly distributed through holes are formed in the perforated plate, the hole opening direction of the through holes is perpendicular to a fixed wall, and the through holes are elliptical holes; the short axis direction of the elliptical hole is the same as the airflow direction; the short axis length of the elliptical hole is greater than the thickness of the acoustic viscosity boundary layer corresponding to the target sound wave frequency; the elliptical holes are uniformly distributed in rows and columns on the fixed wall, and the elliptical holes in adjacent rows are distributed in a staggered manner, so that the elliptical holes in the middle row and the center connecting lines of the left and right adjacent elliptical holes in the front and back rows can form an equilateral triangle. According to the acoustic liner perforated plate, the hole shape of an existing acoustic liner perforated plate is changed into the oval shape from the original round shape, the size of the oval hole is designed, the flow resistance coefficient of the acoustic liner can be reduced on the premise that the overall acoustic performance of the acoustic liner is not changed, the considerable resistance reduction effect is achieved, and therefore oil consumption of an airplane can be reduced.

The invention relates to a method for continuously determining the particle size distribution of solid particles having different particle sizes, which are transported in a transport direction in a transport stream and during which impact with an impinging body provided as a waveguide and generate an acoustic signal, which propagates in the impinging body as a solid-state acoustic wave, and detecting the acoustic signal with a vibration sensor. The invention further relates to a measuring device for carrying out the method. In order to obtain a more accurate result when determining the particle size distribution while taking into account a change in the flow energy of the transport flow, it is proposed to reduce the piezoresistive component of the flow resistance of the striking part of the striking body in the direction of incident flow.

The invention discloses a multi-stage distributed cold trap based on a lunar surface environment, which comprises an arch shell, a sealing film is attached to the inner surface of the arch shell, and a plurality of cold trap units distributed in an array manner are mounted on the inner surface of the arch shell; the cold trap unit comprises a framework, the outer side of the framework is attached to the sealing film, the inner side of the framework is a cold trap inlet and is attached with a selective permeable film with a molecular sieve effect, a microcapsule phase change layer is fixedly arranged on the bottom surface of the framework, and a porous medium made of a high-thermal-conductivity material is embedded in the framework; and the porous medium is arranged in the framework with gradient porosity or gradient porosity. According to the invention, the steam flow resistance is reduced, the surface desublimation active site density is enhanced, the space matching between the heat flux density and the steam flux is realized, the energy mass transfer synergistic efficiency is improved, and the external radiation fluctuation can be buffered, so that the long-term stability of the internal temperature of the cold trap is maintained.

The invention discloses a low-resistance acoustic lining panel based on crescent inclined open pores and a design method thereof, the structure adopts a perforated plate with crescent inclined open pores to replace a circular perforated plate of an original acoustic lining, the crescent opening direction is consistent with the airflow direction, and by reducing the size of the open pores in the flow direction and reducing the airflow entering a cavity, the low-resistance acoustic lining panel is formed. Therefore, the flow resistance of the acoustic liner is reduced, the sectional area of the opening is kept unchanged, and the acoustic performance of the acoustic liner is ensured to be unchanged.

This invention discloses a method for evaluating the microscopic seepage of gas and water two-phase flow in tight, low-permeability gas reservoirs. The method includes: obtaining the basic characteristics of the pore-throat structure of multiple reservoir types; creating a corresponding pore-throat structure schematic diagram for each reservoir type based on its basic characteristics; establishing a corresponding pore-throat structure model for each reservoir type based on its schematic diagram; conducting saturated water experiments, gas-driven water experiments, and water-driven gas experiments sequentially on the pore-throat structure model for each reservoir type; and establishing a porous media model based on multiple experimental results to obtain the flow rate per unit time and flow resistance of the pore-throat size. This invention can realistically and intuitively describe the specific transport mechanism of gas and water two-phase fluids in complex pore-throat structures and the final distribution state of gas and water after transport. It solves the current problem of the disconnect between theoretical and experimental research in microscopic seepage, and the inability of microscopic model gas-water two-phase research to explore the deeper gas-water seepage mechanism in tight, low-permeability gas reservoirs.

Acoustic articles and related methods are provided. Specifically, the present invention provides an acoustic article having a porous layer (102, 104, 106) placed in contact with a heterogeneous filler comprising porous carbon and having an average surface area of 0.1 m2 / g to 10,000 m2 / g. The acoustic article may have a flow resistance of from 10 MKS Rayls to 5000 MKS Rayls. Optionally, the porous layer comprises a non-woven fibrous layer or a perforated film having a plurality of open pores having an average narrowest diameter of from 30 microns to 5000 microns. The heterogeneous filler may enhance low frequency performance without significantly compromising high frequency performance, thickness, or weight.

The present application belongs to the technical field of micro-interface dynamics research, and relates to a method and system for realizing prediction of micro two-phase interface imbibition behavior of porous media, comprising: obtaining a pore network composed of pores and throats according to a target porous medium; calculating the flow rate of injected two-phase fluid at the throat; calculating the fluid flow rate under the main interface displacement mode and the wetting mode displacement mode respectively according to the flow rate of injected two-phase fluid at the throat; determining the displacement mode of the two-phase fluid interface according to the fluid flow rate ratio under the two displacement modes; calculating the corresponding flow resistance at the throat according to the displacement mode of the two-phase fluid interface; updating the motion control equation of the two-phase fluid according to the flow resistance, thereby completing the prediction of the micro two-phase interface imbibition behavior of the porous medium. The present application clearly defines the preferential flow path and dynamic evolution mode of different types of interfaces in the displacement process in the complex pore structure of the porous medium, and realizes accurate discrimination of the fluid interface type under transient conditions.

The present invention discloses an adaptive grouting control and plugging method based on real-time monitoring of mining-induced fissures, which relates to the fields of mine safety engineering and hydrogeological technology. Through the coordinated work of the grouting mechanism, the data monitoring system, the data acquisition and processing module and the adaptive control module, the automation and intelligence of grouting protection can be realized. By introducing the fissure roughness coefficient and the time-dependent viscosity, the flow resistance of the rough fissure and the time-varying characteristics of the slurry rheology are quantified, and the calculation error of the slurry diffusion radius is reduced. Through the joint inversion algorithm of the microseismic travel time residual and the acoustic wave velocity field, combined with the weighted robust LM algorithm to dynamically adjust the data weight, the precise positioning of the fissure is achieved. The PID gain compensation and saturation function mechanism are adopted to achieve adaptive, safe and efficient grouting. The present invention monitors the fissure dynamics in real time through multi-source data fusion technology, and dynamically optimizes the grouting parameters in combination with the intelligent algorithm, effectively suppresses complex geological interference, reduces the waste of slurry materials, and achieves efficient and accurate plugging of mining-induced fissures.

In some embodiments according to the present disclosure, methods for mitigating particle retention are provided including the use of frequency sweep excitation to eject particle in the sweep. In some embodiments according to the present disclosure, the acoustically driven fluid ejector can be capable of being switched between multiple modes of operation. In other embodiments according to the present disclosure, the acoustically driven fluid ejector can be altered such that it includes the capability to be filled with a biocompatible material to aid in the mitigation of particle aggregation in the acoustically driven fluid ejector. In some embodiments according to the present disclosure, the solid structure and number of nozzles of the acoustically driven fluid ejector can be adjusted such that the ejector of the acoustically driven fluid ejector can be self-pumping, i.e. no external pumping mechanism other than acoustics driven flow drag is used.

The application provides a coalescence flow guide module and equipment for strengthening multiphase quick separation, which is composed of "eight" shaped coalescence units formed by first coalescence plates and second coalescence plates respectively inwardly inclined at an angle, and the coalescence flow guide module is formed by horizontal and vertical translation and superposition of the coalescence units; gaps are left between adjacent first coalescence plates and second coalescence plates in the vertical direction; the gaps in the coalescence units form ascending channels in the vertical direction, and the gaps between adjacent coalescence units form descending channels in the vertical direction. The application utilizes the shallow pool principle to reduce the time required for liquid droplets to float or sink, and utilizes the hydrophilicity and hydrophobicity of the material surface of the coalescence plate to improve the liquid droplet coalescence efficiency; the inclined coalescence plate forms completely separated and non-interfering ascending channels and descending channels, so that the multiphase quick separation can be realized, and the application has the advantages of small flow resistance, good coalescence effect and difficult back mixing.

An automotive sound-insulating trim component having spring-mass characteristics comprising a porous fibrous spring layer and a mass layer laminated together, wherein the porous fibrous spring layer has an Air Flow Resistivity lower than 7500Ns / m4 and a Damping Loss Factor equal to or higher than 0.15.