58 results about "Incompressible flow" patented technology

The invention discloses a fluid-solid-sound coupling calculation method based on time domain analysis of an OpenFOAM platform. The fluid-solid-sound coupling calculation method comprises the following steps: decomposing a compressible fluid variable into an incompressible fluid variable and an acoustic pulsation quantity; deducing an acoustic control equation of a flow sound decomposition method under the dynamic grid; discretizing the acoustic control equation by adopting a finite volume method; applying an incompressible flow field boundary condition and an acoustic boundary condition; adopting an OpenFOAM dynamic grid technology to obtain grid information topological information and motion information; a PISO-SIMPLE merging algorithm is adopted to decouple the acoustic control equation; and solving the decoupled acoustic control equation to obtain sound pressure distribution so as to realize fluid-structure interaction vibration noise characteristic analysis. According to the method, the technologies of variable decomposition, fluid-solid coupling and dynamic grids are utilized, far-field linear hypothesis is avoided, acoustic forecasting of far and near fields is guaranteed, meanwhile, the calculation cost is saved, and the analysis efficiency is improved.

The present invention discloses a multi-objective thermal-fluid topological design optimization method for the cooling element of a precision gear grinding machine tool, comprising the following steps: Step 1: Define the design domain: Expand the cooling element into a plane, define a two-dimensional design domain representing the cooling element's geometric structure, and discretize it using the finite element method; Step 2: Numerical modeling: Model the cooling element as a porous medium; Under the conditions of laminar incompressible flow, the fluid dynamics are governed by the dimensionless forms of the continuity equation and the momentum equation; The fluid-solid coupled heat transfer model is governed by the dimensionless energy conservation equation; Step 3: Construct an objective function: The optimization objective is defined as a weighted function of heat transfer and fluid dissipated power, and a fluid-solid heat transfer topological optimization model is constructed; Step 4: Solve the objective function; Step 5: Restore the shape and structure of the cooling element. The present invention also discloses a precision gear grinding machine tool and a cooling element.

The present invention discloses a valve assembly comprising a seat ring, a valve plate assembly movable between a sealed position within the seat ring and an open position outside the seat ring. A fitting can pass through the valve plate, and / or a sensor assembly can extend through the fitting with a sensor mounted below the valve plate assembly. The sensor assembly provides enhanced monitoring capabilities by being positioned in the incompressible fluid column below the valve plate assembly, ensuring accurate sensing of relevant parameters. This configuration allows for efficient and reliable operation of the valve assembly, enhancing its performance and functionality in various applications.

The invention provides a method for predicting the diffusion range of grouting slurry in a coal seam floor area. The method comprises the following steps: acquiring a slurry flooding model containing well field stratum parameters and grouting drilling parameters in the coal seam floor area; based on a Navier Stokes equation and a Darcy law, obtaining a Brinkman equation used for describing incompressible fluid flow caused by the reinforcing material in the porous medium; wherein the Brinkman equation comprises a viscosity item and a pressure gradient item; the grouting pressure, the slurry density, the dynamic viscosity, the porous medium permeability and the porous medium porosity serve as influence factors of slurry diffusion, and various parameter combinations of the influence factors and levels are obtained; and simulating a slurry diffusion process based on the slurry flooding model by using a plurality of parameter combinations and utilizing the Brinkman equation so as to obtain an optimal parameter combination and a corresponding slurry diffusion range. According to the method, the slurry diffusion range can be scientifically and accurately predicted, and the consistency and reliability of the grouting treatment effect are improved.

The invention discloses a multi-objective heat-flow topology design optimization method for a cooling element of a precise gear grinding machine tool, which comprises the following steps of: 1, defining a design domain: unfolding the cooling element into a plane, defining a two-dimensional design domain representing the geometric structure of the cooling element, and discretizing by adopting a finite element method; step 2, numerical modeling: modeling the cooling element into a porous medium; under the condition that laminar flow cannot be compressed, the fluid dynamics is controlled by a dimensionless form of a continuity equation and a momentum equation; the fluid-solid coupling heat transfer model is controlled by a dimensionless energy conservation equation; 3, constructing an objective function, wherein an optimization objective is defined as a weighting function of heat transfer and fluid dissipation power, and a fluid-solid heat transfer topological optimization model is constructed; 4, solving the objective function; and 5, recovering the shape structure of the cooling element. The invention further discloses a precise gear grinding machine tool and a cooling element.

The present invention provides a method for constructing a ship pressure field model in shallow water waves and a target determination method. The method uses ideal incompressible fluid theory to establish the continuity equation and momentum equation satisfied by the ship in the geodetic coordinate system. Based on the shallow water assumption, a depth-averaged perturbation velocity potential is introduced. Combined with the bottom boundary conditions and the free surface boundary conditions, a flow field control equation expressed by the depth-averaged perturbation velocity potential is constructed. The wave source term within the domain is set according to the wave environment, and the moving pressure term is set according to the ship type. The wave source term within the domain and the moving pressure term are substituted into the flow field control equation to simulate the effect of the surface ship disturbance in the wave environment, thereby obtaining the ship pressure field control equation. Based on the ship pressure field control equation, the ship pressure field model is constructed in combination with the initial and boundary conditions of the flow field, as well as the relationship between the flow field pressure and velocity potential. The model is adapted to rapidly calculate the pressure field under different environments, thereby improving the prediction efficiency of the ship pressure field signal.

The invention discloses an incompressible fluid flow numerical solution method based on deep learning and spectral differentiation, and belongs to the technical field of fluid mechanics. The problems that when a neural network is used for solving high Reynolds number flow, calculation burden of a high-order derivative is too heavy, long-time simulation precision of unsteady flow such as vortex shedding is attenuated, adaptability of complex boundaries such as a channel wall face and a periodic boundary group is poor, and a hardware video memory is limited in solving of large-scale flow such as three-dimensional turbulent flow are solved. The method specifically comprises the steps of adopting a solution of a memory-saving reversible neural network approximation equation; deducing a space-time Chebyshev differential matrix to quickly and accurately calculate a space-time partial derivative; a unified spectral discrete format is adopted in the space-time dimension, global space-time information is integrated, and the non-local effect of the flow field is considered. Through fusion of spectral differential and a reversible neural network, a loss function composed of a residual error of a Navier-Stokes equation and an initial boundary condition matching error is optimized, incompressible fluid flow can be efficiently solved on equipment with a limited memory, and complex boundary conditions are adapted.

A landing gear assembly for rotorcraft includes a shock absorber, a ground support assembly and an airframe linkage assembly. The shock absorber includes a force sensor to detect a pressure of an incompressible fluid within the shock absorber and a temperature sensor to detect a temperature of the fluid. The ground support assembly is linked to the shock absorber and includes an axle and a ground contact element movable in relation to the axle. The linkage assembly is linked to the shock absorber and / or the ground support assembly and includes a position sensor to detect movement of the axle between compressed and uncompressed conditions of the shock absorber. Various rotorcraft include one, two, three or more landing gear assemblies and an attitude control system. Various rotorcraft methods process sensor signals from one, two, three or more landing gear assemblies at the attitude control system to provide various rotorcraft functions.

The application discloses a kind of double box girder flow field dynamics modal and flow stability analysis method and system, belong to bridge engineering field.This method first establishes double box girder flow field model by computational fluid dynamics, solves the momentum equation and continuity equation of two-dimensional incompressible flow;Dynamic modal decomposition is carried out again, and eigenvalue, characteristic mode and other information are obtained;Finally, based on linear stability theory, the flow field component is expressed as the sum of steady-state solution and disturbance term, and the global linear flow stability equation is obtained by substituting into the equation, and the flow stability is analyzed by discrete.This method can accurately extract the modal characteristics of each order, providing a scientific basis for wind-induced vibration analysis of double box girder, and has important application value.The method of the application occupies less computing resources, has high numerical accuracy, and can be further expanded to higher precision calculation model according to computing resources, and is suitable for application in actual bridge engineering.

Systems and methods for digitally simulating a fluid flow in a three-dimensional computer-aided design (CAD) model of a simulation space include digitally simulating movement of one or more digital particles representing the fluid from one or more first voxels in a mesh to one or more second voxels in the mesh, performing one or more interaction operations on the one or more digital particles at the one or more second voxels to determine a distribution of the one or more digital particles. A first quantity represented by the distribution of the one or more digital particles is based on a temperature and a pressure at the one or more second voxels and a reference fluid density. A second quantity represented by the distribution of the one or more digital particles is based on the reference fluid density, velocities of the one or more digital particles, and a mean fluid velocity.

A downhole motor control system may identify a downhole compressible density of a drilling fluid using a downhole temperature and a downhole pressure of the drilling fluid, the drilling fluid including an incompressible portion and a compressible portion, the drilling fluid flowing downhole with a downhole compressible flow component and an incompressible flow component. A downhole motor control system may determine the downhole compressible flow component using the downhole compressible density, a surface compressible density of the compressible portion at a surface location, and a surface compressible flow component of the compressible portion at the surface location. A downhole motor control system may identify a downhole compressible fraction of the drilling fluid based on the downhole compressible flow component and the incompressible flow component. A downhole motor control system may generate a composite flow rate of the drilling fluid based on the incompressible flow component and the downhole compressible fraction.

The invention relates to the technical field of metal hose inspection and detection, in particular to a metal hose gas pressure loss test method and system, and the method comprises the steps: S101, carrying out drying treatment on gas, S102, carrying out dynamic pressure adjustment on the gas, S103, carrying out data acquisition and analysis, and S104, outputting a dynamic pressure loss coefficient and an error analysis result. Step S105, adjusting a preset pressure gradient or a flow set value according to an error analysis result until the error analysis result accords with a simulation verification threshold value, and step S106, closing gas supply, releasing residual pressure of the pipeline, and checking the sealing performance of the pipeline and the reset state of the valve; according to the invention, the problems of gas compressible flow characteristic simulation distortion, inconvenient storage tank fixation and condensation interference caused by insufficient drying treatment due to adoption of incompressible fluid in a traditional metal hose pressure loss test are solved; and the problems of poor test stability and simulation analysis errors caused by incomplete data of a single-side metering mode and lack of dynamic cooperative regulation and control are solved.

The present application relates to the field of supply chain logistics scheduling, and provides a supply chain cargo transfer method and system based on multi-agent cooperation, which comprises the following steps: a center node constructs an incompressible fluid continuity equation with a diffusion term, obtains a continuous global navigation field by solving, and distributes the field to edge agents; the edge agents analyze the field gradient vector based on the field, convert the field gradient vector into a speed control instruction, and use the speed control instruction to drive continuous movement; the edge agents detect local physical disturbances, convert the local physical disturbances into field correction parameters, and upload the field correction parameters; the center node takes the field correction parameters as a field update source, substitutes the field correction parameters into a solving process, updates the continuous global navigation field, and distributes the field to form a closed-loop regulation and control. Thus, the instruction confrontation and oscillation between the center discrete path and the edge continuous potential field are eliminated, macro flow control is realized in a flexible and smooth manner, and the system robustness is greatly improved.

The displacement generating device comprises a tetragonal machine body, a motor device, a hydraulic valve and an electric cabinet, and an oil outlet of a hydraulic pump is connected with a port P of the hydraulic valve; a cylindrical bulge, a central blind hole and a radial blind hole are respectively arranged on the lower surface of the machine body, radial, vertical and circumferential oil ducts are arranged in the machine body, a horizontal oil duct is connected with an air filter and a liquid level meter, and a communicating oil duct is arranged in the concave structure; the top cylinder body is connected with the cavity III; the bottom cylinder body is connected with the central blind hole to form a cavity II; the radial oil duct is communicated with the upper and lower blind holes to form a sealing cavity I filled with incompressible fluid; the radial blind holes in the bottom and the circumferential oil duct form a cavity IV which is communicated with a port B of the hydraulic valve; the hydraulic valve A port drives the cavity III to push the top piston rod, fluid is transferred to the bottom piston rod through the cavity I, and hydraulic oil in the cavity IV flows back to the cavity II through the T port. High-precision displacement synchronization is achieved through the incompressible fluid medium, and the positioning and sampling performance of the drilling machine is remarkably improved.

A downhole motor control system may identify a downhole compressible density of a drilling fluid using a downhole temperature and a downhole pressure of the drilling fluid, the drilling fluid including an incompressible portion and a compressible portion, the drilling fluid flowing downhole with a downhole compressible flow component and an incompressible flow component. A downhole motor control system may determine the downhole compressible flow component using the downhole compressible density, a surface compressible density of the compressible portion at a surface location, and a surface compressible flow component of the compressible portion at the surface location. A downhole motor control system may identify a downhole compressible fraction of the drilling fluid based on the downhole compressible flow component and the incompressible flow component. A downhole motor control system may generate a composite flow rate of the drilling fluid based on the incompressible flow component and the downhole compressible fraction.

The present application is directed towards a generator that utilises the properties of a compressible fluid and an incompressible fluid to generate power using a plurality of vessels wherein the vessels are connected in a circuit by a plurality of pipe sections.

Systems and methods for digitally simulating a fluid flow in a three-dimensional computer-aided design (CAD) model of a simulation space include digitally simulating movement of one or more digital particles representing the fluid from one or more first voxels in a mesh to one or more second voxels in the mesh, performing one or more interaction operations on the one or more digital particles at the one or more second voxels to determine a distribution of the one or more digital particles. A first quantity represented by the distribution of the one or more digital particles is based on a temperature and a pressure at the one or more second voxels and a reference fluid density. A second quantity represented by the distribution of the one or more digital particles is based on the reference fluid density, velocities of the one or more digital particles, and a mean fluid velocity.

The invention relates to an actuation device for actuating a vehicle function, comprising: a support device; a fluid pad assembly having at least one fluid pad protruding from the carrier device, the fluid pad including at least one resilient enclosure and a first volume having an incompressible fluid at least partially surrounded by the resilient enclosure; and at least one hydropneumatic accumulator fluidly connected to the first volume, the at least one elastic enclosure absorbing an actuation force of the driver's foot in multiple directions such that a deformation of the at least one elastic enclosure caused by the actuation force results in a reduction in the enclosed first volume and an increase in the internal pressure, the at least one sensor unit detects a deformation of the at least one elastic enclosure caused by the actuating force and forwards it to the at least one evaluation and control unit electrically coupled to the at least one sensor unit, and at least one control unit which generates at least one control signal for controlling the vehicle function as a function of a deformation of the elastic enclosure detected by the at least one sensor unit and caused by the actuating force.

The invention provides a low-Mach-number incompressible flow noise prediction method, a storage medium and computer equipment. The noise prediction method comprises the following steps: after a flow field to be evaluated reaches dynamic stability, performing transient numerical simulation on the flow field by using a low-speed incompressible flow solver to obtain a transient fluid pressure fluctuation value; using an average field solver to calculate an average pressure field and an average velocity field of at least two periods of the flow field after dynamic stabilization; solving an acoustic control equation after the time step flow calculation is finished, wherein the fluctuation pressure is obtained by the difference between the transient fluid pressure fluctuation value and the average pressure field; and then a boundary acoustic variable is updated by using a non-reflection boundary formula. The technical scheme of the invention can be used in the field of numerical prediction of complex engineering flow noise.

The invention discloses an asynchronous GMRES precondition method for AI acceleration of a pressure Poisson equation in incompressible flow numerical calculation, and belongs to the field of computational fluid mechanics. Aiming at the calculation bottleneck of a traditional GMRES method when a pressure Poisson equation is solved, the method adopts an asynchronous parallel AI precondition framework, neural network training and flow field solving are decoupled, and concurrent execution is achieved. The solver thread performs real-time inference by using the current model, and provides high-quality initial guess; the weight is optimized in the background of the trainer thread, and the lagging is tolerated by using the flow field time coherence. Experimental results show that the method shortens the solving time by 67%-82% on the premise of ensuring convergence precision, and is suitable for large-scale fluid simulation.

The invention relates to a device and a method for adjusting a base point of a spring element for a vehicle, comprising a first wall element for connection to the vehicle and a second wall element arranged at a distance therefrom for connection to the spring element, and a chamber arranged between the first and second wall elements, the distance between the first and second wall elements is varied by varying the volume of the chamber, the chamber having an incompressible fluid, the first and / or second wall element having a through-hole for the fluid through the chamber, which through-hole can be connected in fluid communication to an input / discharge device for the fluid in order to vary the volume of the chamber, the chamber has a chamber wall having at least one third wall element extending from the first wall element up to the second wall element, the total amount of substance of which is constant as the volume of the chamber changes, the third wall element having a portion arranged in a suspended manner on a flange of the second wall element, and the third wall element having a portion arranged in a suspended manner on the flange of the second wall element when the amount of fluid in the chamber increases. The third wall piece can be tensioned between the first wall piece and the second wall piece.

Landing gear assemblies, rotorcrafts, and rotorcraft methods are disclosed. A landing gear assembly of a rotorcraft includes a shock absorber, a ground support assembly, and a fuselage coupling assembly. The shock absorber comprises a force sensor for detecting the pressure of incompressible fluid in the shock absorber and a temperature sensor for detecting the temperature of the fluid. The ground support assembly is connected to the shock absorber and includes a shaft and a ground contact element movable relative to the shaft. The coupling assembly is coupled to the shock absorber and / or the ground support assembly and includes a position sensor that detects movement of the shaft between a compressed state and an uncompressed state of the shock absorber. Various rotorcrafts include one, two, three or more landing gear assemblies and an attitude control system. Various rotorcraft methods process sensor signals from one, two, three or more landing gear assemblies at an attitude control system to provide various rotorcraft functions.

The invention relates to a device for adjusting the bottom point of a spring element (12) for a vehicle, the device (10) comprising a first wall element (14) for connection to the vehicle and a second wall element (14) arranged at a distance from the first wall element for connection to the spring element (12), and a chamber (18) arranged between the first wall element (14) and the second wall element (16), for changing the distance between the first wall element (14) and the second wall element (16) by changing the volume of the chamber (18), wherein the chamber (18) contains an incompressible fluid (27), the first wall element (14) and the second wall element (16) are connected to the spring element (12) and the chamber (18) is arranged between the first wall element (14) and the second wall element (16). The wall element and / or the second wall element (16) has a through hole (20) for an incompressible fluid (27) directly reaching the chamber (18), wherein the through hole (20) can be connected to an input / discharge device (22) for the incompressible fluid (27) in a fluid-connected manner to change the volume of the chamber (18), characterized in that the chamber (18) has a chamber wall (24), which has at least one third wall element (25) extending from the first wall element (14) to the second wall element (16), and the mass of the third wall element is constant when the volume of the chamber (18) changes.

The invention discloses a method and a system for analyzing dynamic modality and flow stability of a flow field around a double-box girder, and belongs to the field of bridge engineering. The method comprises the following steps: firstly, establishing a double-box girder surrounding flow field model through computational fluid dynamics, and solving a momentum equation and a continuity equation of a two-dimensional incompressible flow; performing dynamic mode decomposition to obtain information such as characteristic values and characteristic modes; and finally, based on a linear stability theory, representing a flow field component as a sum of a steady-state solution and a disturbance term, substituting the sum into the equation to obtain a global linear flow stability equation, and analyzing the flow stability through discretization. The method can accurately extract modal features of each order, provides a scientific basis for double-box girder wind-induced vibration analysis, and has important application value. The method occupies few computing resources, is high in numerical precision, can be further expanded to a computing model with higher precision according to the computing resources, and is suitable for being applied to actual bridge engineering.

The present invention discloses a method for simulating the temperature field in the roll continuous quenching process based on FLUENT, which includes the following steps: clarify the process machine equipment parameters in the roll quenching process according to the roll speed of the quenching machine and the relevant parameters of each cooling section of the quenching machine; use FLUENT to perform finite element analysis on the jet impingement cooling process of the steel plate in each cooling section and the flow cooling process of the retained water on the upper surface of the steel plate, and analyze the internal surface heat transfer situation of the steel plate in this cooling section based on the basic principle of incompressible fluid flow and the fluid-thermal-solid coupling finite element method to obtain the heat transfer boundary conditions of the steel plate in this cooling section; conduct quenching experiments according to the quenching process parameters in each cooling section, verify the heat transfer boundary conditions obtained by FLUENT, and make corrections; write the surface heat transfer load of the steel plate according to the corrected surface heat transfer conditions to obtain the temperature field in the actual roll continuous quenching process. The present invention can effectively reduce the experimental cost on the premise of ensuring the simulation accuracy and can obtain more accurate temperature field data in the roll continuous quenching process.

A computer system for digital simulation of pseudo-incompressible fluid flow in a computer-aided design model is disclosed. Systems and methods for digital simulation of fluid flow in a three-dimensional computer-aided design (CAD) model of a simulation space include: digitally simulating movement of one or more digital particles representing a fluid from one or more first voxels in a grid to one or more second voxels in the grid; one or more interaction operations are performed on the one or more digital particles at the one or more second voxels to determine a distribution of the one or more digital particles. The first quantity represented by the distribution of the one or more digital particles is based on the temperature and pressure at the one or more second voxels and the reference fluid density. The second quantity represented by the distribution of the one or more digital particles is based on the reference fluid density, the velocity of the one or more digital particles, and the average fluid velocity.

The invention provides a ship pressure field model construction method and a target judgment method in shallow water waves, which adopt an ideal incompressible fluid theory, establish a continuity equation and a momentum equation satisfied by ship navigation under a geodetic coordinate system, and introduce a disturbance velocity potential averaged along the depth based on shallow water assumption. Constructing a flow field control equation expressed by the disturbance velocity potential averaged along the depth by combining a water bottom boundary condition and a free surface boundary condition; setting intra-domain wave source making items according to the wave environment; setting a moving pressure item according to the ship type; substituting the intra-domain wave generation source item and the moving pressure item into the flow field control equation to simulate the water surface hull disturbance influence in the wave environment to obtain a ship pressure field control equation; and constructing a ship pressure field model based on the ship pressure field control equation in combination with the initial condition and the boundary condition of the flow field and the relational expression between the flow field pressure and the velocity potential. The method is suitable for rapid calculation of pressure fields in different environments, and the forecasting efficiency of ship pressure field signals is improved.

Disclosed herein is a system for generating neutrons with thermal fusion, composition for use in the same, and method of using the same. The system comprises a crucible, the crucible having a quantum incompressible fluid and a gas bubble therein, a piston having an end submerged within the quantum incompressible fluid, and a controller coupled to the piston configured to drive the piston to generate an acoustic resonance in the quantum incompressible fluid.

A downhole power generation system (10) comprising a pressure chamber assembly (12) having a first movable element (14, 48, 49) which at least partially encloses a first variable volume chamber (V1A) and a second movable element (16, 48', 49') which at least partially encloses a second variable volume chamber (V1B), each movable element (14, 48, 49, 16, 48', 49') having an exterior surface and an interior surface, and the first and second variable volume chambers (V1A, V1B) being connected by a conduit (18) so that they together enclose a closed volume (V1) containing an incompressible fluid, the conduit (18) providing a path for flow of the incompressible fluid between the first variable volume chamber (V1A) and the second variable volume chamber (V1B) when the first and second movable elements (14, 48, 49, 16, 48', 49') move so that one of the first or second variable volume chamber (V1A, V1B) contracts and the other expands, the system further comprising a generator device (20) which is located in the conduit (18), and which is configured to use the flow of incompressible fluid along the conduit (18) to generate power.

The invention provides a propeller hydrodynamic force rapid estimation method, device, equipment and medium, and the method comprises the steps: adopting a plurality of curved surfaces which are coaxial with a propeller and have different radiuses, cutting a single blade profile of a three-dimensional geometric model of the propeller, and forming blade sections with different radiuses, obtaining a group of quasi two-dimensional curved surface calculation models; performing rapid grid division on each quasi-two-dimensional curved surface calculation area containing the propeller tangent plane, and setting a flow field boundary condition and a flow field initial condition for the divided calculation area; on the basis of set conditions, an incompressible flow pressure correction method is adopted for unsteady numerical calculation, and axial force and circumferential force borne by the curved surface airfoil profile in each divided calculation area under different working conditions are obtained through solving; based on different cross section positions and axial force and circumferential force on each cross section, total thrust and total torque borne by blades of the propeller thruster are calculated through radial integral approximation, so that the problems that mutual influence of flow fields in complex thruster design is difficult to evaluate, and efficiency and precision of a traditional method are unbalanced are solved.