25 results about "Viscous effect" patented technology

The invention provides a damping liquid silicone rubber material which is obtained by curing a damping liquid silicone rubber raw material composition, and also provides damping liquid silicone rubber and a preparation method thereof. The hardness and strength of the liquid silicone rubber material are improved through filling of the MQ silicon resin and the high-white carbon black, meanwhile, a large number of interface areas are formed by the nano-particles and a matrix, microcosmic slippage of the interfaces is generated under the action of dynamic stress, mechanical energy is converted into heat energy through friction and viscous effects between the interfaces and molecular chains, and damping is improved; according to the invention, by introducing methyl-terminated vinyl silicone oil, a silicone rubber chain forms a large number of suspension chain structures, energy dissipation is enhanced, hydrogen-containing chain extension is carried out at a use end, a main polymer has a longer free molecular chain segment to generate a friction effect, and the damping performance of the liquid silicone rubber material is further improved. Experimental results show that the liquid silicone rubber provided by the invention has excellent damping, mechanical and other properties under high hardness.

The invention belongs to the technical field of ocean engineering, and particularly relates to a potential flow-viscous flow real-time coupling hydrodynamic analysis method and system for a floating body with a heaving plate. The method comprises the following steps of: 1, establishing a free surface potential flow model based on a three-dimensional potential flow theory, simulating wave-structure interaction, ignoring a viscous effect, converting a frequency domain result of a hydrodynamic load into a time domain load through a frequency-to-hour method, and taking the time domain load as an input for solving a motion state; 2, establishing an unbounded viscous flow CFD model, viscous force not covered by a potential flow model and an updated unbounded turbulent flow field around the heaving plate, and calculating the viscous force of the heaving plate; 3, establishing an unbounded potential flow model, and separating a force component repeated with the potential flow from a viscous flow result; 4, integrating the potential flow force and the viscous force to solve a floating body motion equation, iteratively updating the motion state and feeding back the motion state to the two solvers. The method is used for solving the problems that the efficiency is correspondingly reduced if the precision is improved and the precision cannot meet the requirement if the efficiency is improved in the prior art.

The invention belongs to the technical field of transformers, and particularly relates to a dry-type transformer which comprises a shell, a sealing door is arranged on one side of the shell, and a transformer body is mounted in the shell; a water storage tank is formed in the shell and used for storing water, and the water is used for reducing noise when the transformer body works; a water inlet groove is formed in the top surface of the shell, and the water inlet groove is communicated with the water storage groove; the water storage tank is filled with water, then the end opening of the water storage tank is sealed by means of the sealing plate, at the moment, when noise generated during working of the transformer body is spread in water, a large amount of sound energy is consumed through friction and viscous effects of sound waves and water molecules, spreading of the sound waves can be greatly hindered, and therefore the noise reduction effect is achieved; and meanwhile, the water can absorb heat generated when the transformer body works, so that the cooling effect is achieved.

The invention discloses a sound-absorbing rubber material and a preparation method thereof, and belongs to the technical field of rubber preparation. The method comprises the following steps: mixing latex with micro-nano spherical hollow powder, centrifugally stirring in vacuum, mixing with raw natural rubber and a processing aid for banburying, then carrying out open milling, adding a vulcanizing agent, extruding, and finally vulcanizing to obtain the rubber. A micro-nano spherical hollow powder material treated by latex is introduced in the rubber production process, so that sound waves enter the material through a surface perforated structure on the premise of ensuring that the mechanical property of the rubber material meets the use requirements, and are continuously reflected and propagated in an internal hollow structure, air in pores vibrates, and the mechanical property of the rubber material is improved. And through the viscous effect and the heat conduction effect, sound wave energy is converted into heat to be lost, and therefore the effects of sound absorption and noise reduction are achieved.

The application provides a method for determining the structural temperature field and thermal deformation of a compressor rotating disc cavity, which can be applied to the technical field of heat analysis of turbomachinery. The method comprises the following steps: obtaining the geometric parameters, operating parameters and working substance property parameters of the gas in the disc cavity; based on the balance between the buoyancy effect and the viscous effect driven by the centrifugal force, the average heat flux density of the outer ring cover of the disc cavity is obtained according to the outer ring cover radius, the axial gap of the disc cavity, the rotating disc speed, the outer ring cover temperature, the rotating core zone temperature, the Prandtl number, the density, the dynamic viscosity and the thermal conductivity; based on the heat conduction analogy relationship of the laminar Ekman boundary layer, the local heat flux density of the rotating disc is obtained according to the rotating disc speed, the kinematic viscosity, the thermal conductivity and the difference between the rotating disc temperature and the rotating core zone temperature; and the structural temperature field distribution and the thermal deformation of the rotating disc cavity are obtained according to the average heat flux density of the outer ring cover of the disc cavity and the local heat flux density of the rotating disc.

The invention discloses a wave rider shape approximate optimization method based on an agent model. According to the method, the parameterized shape of the waverider is established and passivated by adopting the CST method, the three-dimensional viscous effect and the front edge passivation effect of the shape of the waverider are considered, and the flight surface grid local parameters are generated by adopting the Jacobian conversion method, so that automatic updating of the waverider space grid in the optimization process is realized; then, the aerodynamic / thermal characteristics of the waverider are calculated based on a Reynolds average Navier-Stokes equation (RANS); the method comprises the following steps: constructing a waverider shape optimization problem by taking the maximum lift-drag ratio as an optimization target, solving the optimization problem by adopting an agent model assisted constraint optimization algorithm, and circularly selecting new sample points to update an agent model based on a certain point adding criterion in the solving process until approximate optimization convergence. According to the method, the optimization efficiency can be effectively improved, the design period is shortened, and optimization and modification of the wave rider shape scheme can be rapidly achieved in the overall design stage.

The utility model relates to the technical field of sound insulation boards, and provides a sound insulation board capable of improving the sound insulation effect of a house, which comprises a main board, a sound insulation layer and a back board, the main board is assembled and connected with the back board through the sound insulation layer, two sides of the sound insulation layer are respectively assembled and connected with the main board and the back board through cork layers, and the interior of the sound insulation layer is of a hollow structure. A plurality of honeycomb cylinders are arranged in the sound insulation layer, the honeycomb cylinders form a honeycomb structure, micropores are formed in the sound insulation layer right above the honeycomb cylinders, pyramids are arranged on the lower portions in the honeycomb cylinders, slope tops are arranged at the upper ends of the pyramids, and silencing grooves are formed in the surfaces of the pyramids. After sound enters the sound insulation layer, the sound is reflected for multiple times among the honeycomb cavities, the pyramids and the silencing grooves, so that part of sound wave energy is converted into heat energy, the glass wool layer on the surface of each pyramid is made of porous sound absorption materials, when the sound makes contact with the glass wool layer, the sound is dissipated due to the air viscous effect and internal reflection, and the sound insulation effect is further improved.

The invention relates to the technical field of aerospace, in particular to a supersonic aircraft unsteady aerodynamic force prediction method considering a viscous effect, which comprises the following steps: establishing a CFD model of an analysis object, solving an N-S equation, and exporting near wall surface flow field parameters; on the basis of the near wall surface flow field parameters, radial basis function interpolation is adopted to obtain flow field parameters at any distance in the normal direction of the wall surface; based on the parameters of the flow field at any distance along the normal direction of the wall surface, solving a boundary layer thickness equation by using a Stevanson iteration method to obtain an effective shape of the aircraft; based on the effective shape of the aircraft, solving unsteady aerodynamic force under given displacement and speed boundary conditions by adopting a three-dimensional discretized local flow piston theory; according to the method, the calculation efficiency and calculation precision of the unsteady aerodynamic force can be improved.

The application discloses a jet type elastic ring extrusion oil film damper. The damper is arranged at a rotor bearing support position and mainly comprises a bearing seat, an outer oil film bushing, an elastic ring, a jet device and a bearing outer bushing. In the damper, the damping and vibration reduction effect is achieved by the flow of lubricating oil under the deformation of the elastic ring, the exchange of the flow among the jet device, the outer oil film and the oil cavity and the viscous effect. Compared with general elastic ring extrusion oil film dampers, the damper can not only improve the speed gradient of lubricating oil and the energy dissipation rate by using the jet device, but also can avoid stress concentration on the elastic ring to ensure a long service life of the structure. The damper has the advantages of compact structure, high damping and adjustable damping performance by changing the structural parameters of the jet device.

The invention provides a method and a device for determining an entrainment area. Relates to the technical field of aero-engine cooling, and the entrainment area determination method comprises the following steps: determining Lamm vectors of airflow at a plurality of spatial points according to vorticity and speed of the airflow at the plurality of spatial points in a vortex field; the vortex field is generated by entrainment of a cold air jet flow ejected by a first air film hole in a turbine blade on a main flow; dividing a first entrainment area in the vortex field based on the pointing direction of the Lamm vector of the airflow in the vortex field at the plurality of spatial points; dividing a second entrainment area in the vortex field based on the pointing direction of the speed of the airflow in the vortex field at the plurality of space points; dividing a third entrainment area in the vortex field according to a space point of the viscous effect of the cold air jet flow on the main flow in the vortex field; and obtaining a target entrainment area based on the first entrainment area, the second entrainment area and the third entrainment area.

The embodiment of the invention provides an ultra-micro-pore composite sound absorption and insulation board. The ultra-micro-pore composite sound absorption and insulation board comprises an ultra-micro-pore sound absorption board, a first non-woven fabric layer, an aluminum honeycomb core layer, a first-pore-diameter aluminum board, a centrifugal glass sound absorption cotton layer, a second non-woven fabric layer and a second-pore-diameter aluminum board. The upper end of the ultra-micropore acoustic board is provided with a triangular cloth grain stretching hole and a micro-wave structure, so that first-wave acoustic energy absorption is realized; the aluminum honeycomb core layer attenuates second wave sound energy through cavity resonance and a particle viscous effect; the first aperture aluminum plate and the second aperture aluminum plate are combined with the centrifugal glass wool layer to further absorb residual sound waves. The multilayer structure has a synergistic effect, has broadband (especially low-frequency) efficient sound absorption performance, has the characteristics of high bending resistance, compressive strength and light weight, and is suitable for occasions with harsh mechanical load and acoustic environment, such as industrial factory buildings, traffic facilities and the like.

The utility model provides an assembly type building prefabricated wallboard with an anti-seismic energy dissipation structure, and relates to the technical field of building prefabricated wallboards, the assembly type building prefabricated wallboard comprises a front wallboard main body, the rear end face of the front wallboard main body and the front end face of a rear wallboard main body are fixedly installed and connected through an adhesive, and at the moment, a rear containing groove and a front containing groove jointly form a sound absorption energy dissipation cavity; sound waves enter the sound absorption cavities with the interior being of a spherical structure, the incident sound waves are subjected to the total reflection effect through the inner circumferential arc faces of the spherical cavities, and sound energy is converted into heat energy to be consumed through multiple times of reflection attenuation of the sound waves in the cavities in combination with the friction of the wall faces of the cavities and the viscous effect of air media; a continuous acoustic conduction network is formed, after sound waves are reflected for multiple times in a single spherical cavity, part of energy enters the adjacent cavities through the sound conduction reflection holes, the cross-cavity linkage reflection energy consumption process is triggered, and the problem that the sound wave treatment capacity of a traditional prefabricated wallboard is limited, and the comprehensive requirement of a building cannot be met is solved.

The invention relates to the technical field of runout detection, and particularly discloses a pump shaft runout detection device which comprises a working condition simulation unit, a working condition switching unit and a disturbance triggering unit. Simulation and switching of multiple core working conditions of stable operation, load abrupt change and start-stop viscosity of the pump shaft assembly are achieved through the working condition simulation unit, the working condition switching unit and the disturbance triggering unit. Through the periodic pulsation impact of the transient impact disturbance part, the transient impact load generated by the sudden load change on the pump shaft assembly is simulated; through periodic pulsation impact of the transient variable acceleration disturbance member, a special jumping working condition caused by a friction viscous effect in a starting or stopping process of the pump shaft assembly is simulated. Performance and safety of the pump shaft assembly under different working conditions can be comprehensively evaluated, and the goodness of fit between test data and actual working conditions is improved.

The application discloses a kind of gas electromechanical inerter energy feeding device for wheel hub drive car, including gas type inerter, linear motor connected with gas type inerter, the buffer stroke chamber is also equipped between gas type inerter and linear motor, the upper welding of gas type inerter has upper lifting ring, the lower welding of linear motor has lower lifting ring.The beneficial effects of the present application are that the gas electromechanical inerter energy feeding device for wheel hub drive car is coupled by gas electromechanical inerter and linear motor, the flow inertia of fluid in spiral copper pipe is used to realize the effect of inerter, compared with liquid inerter, it has higher linearity degree;The hydraulic oil in its spiral copper pipe is only in two liquid plugs, i.e.the hydraulic oil flows within a certain range, and will not flow into the cylinder, the viscous effect is weakened, and the power loss is greatly reduced.

The present application relates to a kind of mineralization behavior detection device of floating particle and bubble, belong to mineral flotation technical field, solve the problem that the actual flotation environment does not conform to the problem caused by less test factors in the test equipment in prior art.The present application includes test system, water circulation system and shooting system;Test system includes top cover drive shelter, connecting channel and fluidized tank, and the lower end of top cover drive shelter is connected with the top of fluidized tank by connecting channel;Water circulation system is communicated with top cover drive shelter, and shooting system is used to shoot the mineralization behavior of particle and bubble in top cover drive shelter.The present application applies flowing fluid in the top of top cover drive shelter, due to the influence of boundary condition, fluid layer close to top cover will first move, then this movement is transmitted to the fluid layer below by viscous effect, with the development of flow, one or more eddies with different rotation directions will be formed in the chamber, and different flow field structure and intensity can be simulated.

The utility model relates to the technical field of centrifugal fans, in particular to a bionic vortex noise reduction centrifugal fan volute structure which comprises a bionic vortex main volute, an air inlet is formed in one side of the bionic vortex main volute, and an air outlet is fixedly connected to one end of the bionic vortex main volute. A plurality of guide vanes are uniformly and fixedly connected to the surface of the inner wall of the air outlet, a fixing seat is fixedly connected to the other side of the bionic vortex main volute, a plurality of reinforcing ribs are uniformly and fixedly connected to the surface of the fixing seat, and a porous sound absorption material is pasted to the surface of the inner wall of the bionic vortex main volute; a plurality of spiral protrusions are fixedly connected to the two sides of the inner wall of the bionic vortex main volute, through the arrangement of the porous sound absorption material, the porous sound absorption material is made of porous foamed aluminum or glass wool or polyurethane foam in the using process, when noise is spread in the volute, part of the noise enters pores of the porous sound absorption material, and the sound absorption effect is improved. And sound energy is converted into heat energy through friction and viscosity effects, so that the noise intensity is attenuated.

To provide an airborne ultrasonic transducer (ultrasonic sensor) with high sound pressure and a wide bandwidth.SOLUTION: When ultrasonic waves are transmitted, an ultrasonic sensor places an elastic body 3 having a loss tangent tanδ, which is the ratio of storage modulus to loss modulus, of 0.001 or more and 0.6 or less in all or part of the area between a part 9 on the bottom surface of a bottomed cylindrical case 4 where the amplitude is maximum and the vibration node 10 on the bottom surface of the bottomed cylindrical case where the amplitude is minimum. This suppresses changes in vibration at the boundary between the two vibrations mentioned above due to the viscous effect of the elastic body, which is subjected to stress according to the deformation speed, and prevents a decrease in the radiation efficiency of sound waves even when the drive frequency and resonant frequency do not match.SELECTED DRAWING: Figure 1

According to the micro-flow pipeline design method for generating the constant tensile force by using the variable-section pipeline, a tensile strain rate field with uniform space distribution is formed in a contraction area of the micro-flow pipeline designed according to the method, and the problem that the tensile force in a traditional linear contraction pipeline changes dramatically along with the position is solved. According to the structure, the tensile force borne by the target object at different positions of the pipeline is basically kept constant, so that the requirement for the positioning precision of an observation area is greatly reduced, system errors caused by sampling position differences are effectively eliminated, and the accuracy of biomechanical characterization is remarkably improved. On the basis of an ideal flow model, flow distortion caused by the side wall viscous effect under the micro-scale is compensated through structure correction by further combining channel depth-to-width ratio parameters. According to the geometric optimization method based on the actual flow characteristics, the space uniformity of a drawing force field is remarkably improved, and the geometric optimization method is particularly suitable for flow channel structures, such as shallow channels, which are easily influenced by the three-dimensional boundary effect.

This invention discloses a method for estimating clamping force in an electric vehicle EMB system based on a pressure sensorless system, relating to the field of distributed electric drive drive-by-wire vehicle technology. Considering the viscous effect between the brake disc and friction pads during actual braking, a dynamic stiffness model of the clamping force is established to predict the clamping force. The descriptive equation of the dynamic stiffness model is discretized, and a discretized state-space equation for the clamping force is established. Based on the motor torque balance equation, a sliding mode observer for the motor load torque is designed to observe the motor load torque in real time during braking. According to the transmission model of the EMB system, the load torque observation value observed in real time by the sliding mode observer is converted into the clamping force observation value. Using a Kalman filter algorithm, combined with the discretized clamping force state-space equation and the clamping force observation value, and based on the optimal clamping force estimate obtained at the previous moment, the optimal clamping force estimate for the current moment is calculated, achieving real-time optimal estimation of the clamping force. This invention solves the problem that under pressure sensor control, the high temperature and high pressure during braking cause a decrease in the measurement accuracy of the pressure sensor or even its overall failure.

The utility model relates to the technical field of volute structures, in particular to a volute structure for reducing water conservancy pulsation, which is characterized in that fluid with larger water conservancy pulsation flows along a flow guide structure after entering a flow guide groove due to viscous action and adhesive force of liquid, pressure pulsation is gradually reduced, and finally the fluid is converted into balanced pulseless fluid. Therefore, the water conservancy pulsation is effectively reduced; comprising a lower volute and an upper volute, the upper volute is installed at the top end of the lower volute, an inlet is formed in the top end of the upper volute, and an impeller is arranged in the lower volute; the volute further comprises a first flow channel, a second flow channel and flow guide structures, the first flow channel is arranged on the outer side wall of the upper volute in a communicating mode, the second flow channel is arranged on the lower volute in a communicating mode, the first flow channel is communicated with the second flow channel, and the flow guide structures are arranged on the inner side wall of the first flow channel and the inner side wall of the second flow channel correspondingly. The flow guide structure adds four flow guide grooves in the first flow channel and the second flow channel.

The utility model provides a novel ultra-thin broadband sound absorption composite structure, which comprises a plurality of silencing units, each silencing unit comprises a shell, the plurality of silencing units are mutually contacted pairwise on the same plane to form a three-dimensional ultra-thin broadband sound absorption composite structure, a top plate of the shell is a micro-pore plate, and the micro-pore plate is arranged on the top plate of the shell. A partition plate and a tubular structure are further arranged in the shell, a cavity is reserved between the partition plate and a bottom plate of the shell, and the tubular structure is connected with the microporous plate and the partition plate. Sound waves firstly enter the silencing units through the micropore plates and the tubular structures on the silencing units, and due to the resonance effect of the micropore plates and the viscous effect of the tubular structures, the sound waves entering the silencing units are reduced for the first time; the sound waves entering the shell encounter the first-layer cavity between the partition plate and the microporous plate and the second-layer cavity between the partition plate and the bottom plate and generate resonance with the two cavities, secondary sound energy loss is achieved, and the good sound absorption effect at low, medium and high frequencies is achieved.

The present application belongs to the technical field of flutter analysis of supersonic vehicles, and proposes a supersonic flutter analysis method based on the viscous local flow piston theory. The method obtains the interference flow field of large attack angle and complex shape by numerically solving the N-S equation through CFD, and then obtains the effective aerodynamic shape of the vehicle according to the vorticity criterion; the surface of the vehicle is discretized to obtain a high-fidelity three-dimensional aerodynamic grid suitable for the piston theory; the flow field parameters and structural modal shapes at the effective shape of CFD are interpolated onto the piston grid by using the thin plate spline interpolation method, the generalized aerodynamic influence coefficient matrix is calculated, and the state space form of the structural dynamics equation is assembled; the flutter analysis is carried out by analyzing the eigenvalues of the state space equation. The analysis method can analyze any complex aerodynamic shape and consider the viscous effect of real gas, and has high calculation accuracy and efficiency.

The invention discloses a fault finite element analysis method based on a viscoelastic model, a computer device and a storage medium, a search mechanism of a viscous model is introduced, and an optimal three-dimensional viscoelastic finite element model of a target fault area is obtained. According to the method, the response of the fault locking degree to different stress field conditions can be analyzed more comprehensively, the evolution characteristics of the fault under a viscous model can be understood, and especially in the long-term stress accumulation and release process, the possible important influence of the viscous effect on fault sliding and locking behaviors can be understood; the inversion method adopted by the invention has relatively strong robustness, can well explain the locking behavior under the elastic model, and still can maintain relatively high calculation precision in an area with relatively large geological condition change.

The invention discloses a novel turbine. The novel turbine comprises a center shaft, a turbine shell and at least one stage of turbine assembly. The turbine assembly is an integrated rotor formed by welding a plurality of coaxially stacked turbine discs, and the key improvement is that a plurality of half-moon-shaped sheets are uniformly welded between the edges of the adjacent turbine discs to serve as turbine blades. By means of the structure, when a high-pressure working medium flows in, the high-pressure working medium can impact the surfaces of turbine blades to generate recoil force to directly drive a rotor and can also enter disc gaps to do work through the viscous effect, and dual efficient energy conversion of impact and viscosity is achieved. The multiple stages of turbine assemblies are coaxially connected in series and are connected through the I-shaped connecting piece with the internal gas guide pipe, the power can be remarkably improved, and gradient utilization of energy is achieved. The application of the turbine in the fields of new energy stable power generation, aero-engine fan boosting and the like is further expanded, and the turbine has the outstanding advantages of being compact in structure, high in power density, flexible to control, high in adaptability and the like.

The present application relates to the field of material science, disclose a kind of asphalt concrete pavement section joint crack resistance method and system based on net taste technology, the method comprises: fitting the pavement section joint model of section joint;Analysis of the damage zone and fracture zone of pavement section joint model, analyze the material stiffness modulus and material relaxation modulus of asphalt concrete;Construction of the viscoelastic damage model of asphalt concrete, calculate the viscoelastic damage coefficient of asphalt concrete, analyze the asphalt viscoelasticity of asphalt concrete;Fitting the crack analysis model of section joint, simulate the pavement damage evolution of section joint;Chemical additives and asphalt concrete are mixed, analyze the viscous effect of geotechnical mixture material;Determine the optimum elastic modulus of geotechnical mixture material, analyze the crack resistance effect of geotechnical mixture material, execute the crack resistance scheme of corresponding section joint of asphalt concrete pavement.The present application can improve the crack resistance effect of asphalt concrete pavement section joint.