104 results about "Continuity equation" patented technology

The invention belongs to the related technical field of heat dissipation of electronic equipment, and discloses a liquid cooling device and a preparation method and application thereof, and the method comprises the steps: S1, enabling a control equation of the liquid cooling device to be equivalent to a continuity equation, an N-S equation and a heat transfer equation based on equivalent parameters; s2, taking the minimum average temperature and energy dissipation of the whole design domain of the liquid cooling device as a target function, taking the volume fraction of the fluid domain as a constraint condition, and constructing a topological optimization model based on a continuity equation, an N-S equation and a heat transfer equation; s3, an optimization solver is adopted to carry out iterative solution on the topological optimization model, whether a result meets a convergence condition or not is judged, if yes, a topological structure is output, and the step S4 is executed; otherwise, updating the design variable of the topological optimization model, and turning to the step S1; and S4, the three-dimensional model of the liquid cooling device is corrected based on the obtained topological structure, and then blowing forming is carried out based on the corrected three-dimensional model to obtain the liquid cooling device. According to the invention, the cost is reduced.

The invention discloses a simulation method, device and equipment for predicting flow and deformation of a porous medium and the medium. The method comprises the steps that a computational domain is selected, a corresponding computational grid is generated, and porosity initialization is conducted on the computational domain; determining a time step length and a discrete format, and setting a non-uniform factor to solve a control equation set which comprises a continuity equation, a fluid dynamics equation, a skeleton mechanics equation and a porosity updating equation; and analyzing and displaying a solving result. According to the porous medium flow and deformation simulation method independent of hypothesis and empirical parameters, the method is based on the basic principle of the microcosmic fluid-solid coupling effect, a porous medium fluid-solid coupling body kinetic equation is adopted, the situation that a traditional modeling method depends on volume averaging hypothesis and depends on a multi-phase interaction model is avoided, and the modeling efficiency is improved. The method has cross-scale applicability, and provides a new theoretical basis and prediction means for the development of technologies related to porous medium multiphase dynamics and multi-field coupling problems.

The invention relates to the technical field of fluid-solid coupling, in particular to a rock-soil body fluid-solid coupling simulation method and system. Firstly, a fluid-solid coupling model is constructed according to a rock-soil body balance equation, a seepage continuity equation and a permeability function considering deformation influence, and the fluid-solid coupling model can realize bidirectional coupling of a stress field and a seepage field, so that the fluid-solid coupling process of the rock-soil body is more accurately simulated through the fluid-solid coupling model; in addition, the fluid-structure interaction model uses many parameters, including mechanical parameters and permeability parameters, so that the inversion efficiency is low; according to the method, an orthogonal test method is adopted to carry out sensitivity analysis on the fluid-solid coupling parameters of the rock-soil body, parameters sensitive to monitoring data are obtained, only target parameters are inverted, the number of the inverted parameters is reduced, and therefore the parameter inversion efficiency is remarkably improved; the invention further provides a model parameter inversion method based on the long and short term memory neural network.

The invention discloses a fluid-structure interaction numerical simulation method, device and equipment and a medium, and the method comprises the steps: selecting a fluid-structure interaction computational domain, generating a computational grid, and marking the computational domain according to fluid and solid distribution information; determining a solving time step length and a discrete format, and selecting a control equation set for solving, the control equation set comprising a continuity equation, a fluid dynamics equation, a solid dynamics equation and a phase transfer equation; and analyzing and displaying a solving result. According to the efficient fluid-solid coupling numerical simulation method, global unified calculation is achieved, explicit fluid-solid decoupling is not needed, a global fluid-solid coupling body kinetic equation is adopted, errors caused by fluid-solid decoupling processing in a traditional split-phase solving method are avoided, and the method does not need to depend on and repeatedly generate a complex body-fitted grid; the control equation is based on each phase conservation equation on a physical continuous domain and realizes interphase accurate association through an interface continuity condition, and the fluid-solid coupling problem can be accurately and quickly solved.

The invention belongs to the technical field of grouting simulation, and particularly discloses a non-linear coupling simplified filling fracture flowing water grouting simulation method and system.The method comprises the steps that a geometric model of a to-be-simulated area is built, a fluid continuity equation and a momentum equation are built based on initialized model parameters, and a simulation result is obtained; the grouting pressure and the grouting speed of the current time step are calculated; a concentration field equation is constructed according to the velocity field of the current time step, and the slurry concentration distribution and the grouting velocity of the current time step are obtained through coupling solution based on the discrete concentration field equation and the momentum equation; a phase fraction equation is constructed according to the grouting speed of the current time step, and the slurry diffusion form in the water-rich filling fracture of the current time step is obtained; and repeating the process for each time step to finish the simulation of the flowing water grouting of the water-rich filling fracture. According to the method, the calculation efficiency and precision are considered while the algorithm is simplified, and accurate description of the slurry flow characteristics in the fractured porous medium is realized.

The present invention discloses a method for predicting fracture morphology considering interlayer weak planes, comprising the following steps: establishing a three-dimensional geological model according to the formation parameters of the actual interactive strata obtained; establishing a rock seepage-stress coupling model based on the stress balance equation, the continuity equation and the boundary conditions; determining the fracture extension and expansion criterion; inputting the fracturing well parameters of the target well area, establishing a three-dimensional full coupling model for fracturing; simulating the influence of different geological factors and engineering factors on fracture morphology. The present invention is based on the finite element method, establishes a full three-dimensional seepage-stress coupling model, uses the Cohesive pore pressure unit to preset two fracture surfaces, considers interlayer weak planes or bedding weak planes, studies the influence of different geological factors and engineering factors on fracture morphology, can quickly predict the fracture morphology during the fracturing of reservoirs containing interlayer weak planes and guide the design of fracturing construction parameters.

The invention relates to the technical field of environmental governance, and discloses an alpine region reservoir area water and sediment scheduling and water quality scenario prediction method comprising the following steps: river network segmentation and node classification; embedding ice kinetic parameters; transporting and correcting low-temperature silt; carrying out low-temperature adaptation on water quality parameters; performing dynamic boundary transfer and joint solution; and carrying out synchronous real-time iterative calculation. According to the method, ice kinetic parameters are embedded in a one-dimensional Saint-Venant equation, and the coupling relation between the thickness of the ice cover and the hydraulic element is dynamically solved by correcting the effective cross-section area in a continuous equation and the friction gradient in a momentum equation and adopting an iterative algorithm. Therefore, the water level fluctuation in the ice dam forming and outburst process is accurately described, and the problem that an existing model is insufficient in response to ice period hydraulic sudden change is solved.

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 application discloses a fracture diagnosis method and device for fracturing, which belongs to the technical field of fracturing and exploitation of oil and gas reservoirs. The diagnostic method establishes a water hammer equation group through the water hammer continuity equation, the water hammer motion equation and the liquid elasticity equation; solves the water hammer equation group to obtain the distribution equations of the head, flow velocity and density in the middle well section; determines the initial conditions in the studied wellbore, and obtains the expressions of the head, flow rate and density distribution in combination with the distribution equation; couples the water hammer equation group with the wellhead flow boundary conditions and the bottom hole fracture boundary conditions to calculate and obtain the water hammer pressure curve; and determines the fracture parameters by adjusting the fracture related parameters in the bottom hole fracture boundary conditions. The device includes a memory and a processor for storing a computer program, and the program includes the steps corresponding to the above method. The present application quickly diagnoses the fracture related parameters after fracturing based on the water hammer pressure during fracturing, and provides a basis for the design and modification of the oil and gas resource reservoir transformation plan, thereby improving the fracturing transformation effect.

A system and method for measuring or for estimating flow or flowrate of a fluid, including wastewater inflow or infiltration, using non-contact depth-based flow measurement, including: receiving a depth sensor signal from an ultrasonic depth sensor positionable over a manhole channel above an outgoing pipe's crown; receiving a temperature signal from a temperature sensor positionable within the manhole channel; receiving one or more data input signals; calculating a distance to a surface of the fluid based on the received depth sensor signal; and determining a depth of the fluid in the manhole channel based on the calculated distance. Flow velocity may be calculated using Manning's equation or the Hazen-Williams equation, with flow rate subsequently determined using the continuity equation. Alternatively, flow velocity and flow rate may be estimated using a machine learning model trained on simulated or historical time-series data of flow rate, flow velocity, and flow depth, along with pipe attributes, to generate real-time flow estimates based on current and prior flow depth measurements.

The invention relates to the technical field of foam oil evolution, in particular to a seepage prediction method based on foam oil evolution and local time step encryption, which comprises the following steps: constructing a reservoir geological conceptual model by using rock physical parameters, fluid characteristic parameters and reservoir basic data; defining CO2 foam oil reaction and reaction parameters of the reservoir geological conceptual model in the reservoir geological conceptual model; setting phase permeability parameters of the three-phase fluid; well group parameters are imported, and a production system is determined; setting initial parameters of the reservoir geological conceptual model; solving a pressure field of each step in an allowable material balance error range based on material balance, a continuity equation and a phase state balance equation of the seepage field; and adjusting local encryption time steps, and optimizing model numerical calculation parameters. The method solves the problem that the traditional method is difficult to consider the generation, breaking and phase change of each substance, so that the substance balance error is large.

The invention relates to the technical field of numerical simulation calculation of water conveyance projects, in particular to a water recession model establishment method and system based on a long-distance pressure pipeline. The method comprises the steps that a rigid water column model is constructed based on deformation of a motion equation and a continuity equation in the non-constant flowing process of fluid in a pressure pipeline, and a water column flow velocity equation and a water column length equation are established to describe liquid phase changes in the non-air-valve water recession process by combining change analysis of hydraulic parameters in the pressure pipeline on the time scale. The pressure intensity in a hollow pipe section at the upstream end of a pressure pipeline without an air valve is analyzed to describe the volume change in the hollow pipe section to construct an air-valve-free water recession model, the change of gas parameters of air passing through the air valve in the hollow pipe section at the upstream end of the pressure pipeline on the time scale is analyzed to construct an air-valve water recession model, and simulation is solved through the model. And predicting the change trend and fluctuation condition of the pressure water head in the upstream end hollow pipe section in the water recession process of the pressure pipeline. The method can accurately predict the recession process of the long-distance water delivery pipeline.

According to the optimization design method for the pilot-operated overflow valve system, firstly, a flow continuity equation and a force balance equation of a pilot-operated overflow valve are established, then, a pressure and flow relation equation and a state equation are established, and finally, the state equation is solved. In the step of optimizing the mathematical model, three sub-targets of the maximum overshoot, the steady-state error and the root-mean-square error of the system pressure value of the pilot-operated overflow valve system are firstly established, then a multi-target function is established according to the sub-targets, then design variables are selected, constraint conditions are established, and finally the mathematical model is optimized and solved. According to the optimization design method for the pilot-operated type overflow valve system, the diameter of the damping hole of the main valve, the coefficient of the valve port of the main valve and the maximum overshoot of the pressure of the pilot valve in the pilot-operated type overflow valve system are all optimized, and the comprehensive performance of the pilot-operated type overflow valve system is improved.

The invention provides a method for evaluating and predicting the internal erosion resuspension amount of submarine sediments under the action of waves, which is based on a mass conservation equation, an erosion constitutive equation and a seepage continuity equation of sediment particles and considers the influence of accumulation of seabed pore water pressure on the internal erosion process of the sediments under the action of the waves. Meanwhile, the influence of seabed soil physical property change caused by internal erosion on the seabed accumulated pore water pressure development process is considered, a seabed accumulated response-internal erosion coupling mathematical model under the wave action is constructed, and a finite element method is used for solving; and the development change of the accumulated pore water pressure, the porosity, the suspended fine particle volume concentration and the eroded fine particle mass of the seabed is obtained. According to the method, the mass of fine particles in the seabed sediment moving outwards along with seepage under the action of waves and the spatio-temporal evolution characteristics and rules of the erosion process in the sediment are quantitatively evaluated, and therefore quantitative prediction analysis can be conducted on the seabed stability and the erosion resuspension characteristics in the seabed sediment.

The invention discloses a permafrost region product oil pipeline commissioning simulation method based on a discrete cavitation model. The permafrost region product oil pipeline commissioning simulation method comprises the steps that an equation set of a water head H is obtained based on deformation of a continuity equation and a momentum equation of pipeline transient flow simulation; on the basis of the continuity equation and the momentum equation, a pipeline along-line temperature drop calculation formula is introduced in combination with temperature conditions; dividing computational grids according to a finite volume method, solving a water head H equation set by adopting a characteristic line method to obtain a compatibility relational expression, and obtaining uniform time step length and space step length; the gas phase volume is described based on pressure boundary conditions and a compatibility relational expression, multiphase transient flow is calculated by combining a discretization equation, a single-temperature hypothesis and a single-speed hypothesis, a pressure time-varying curve along a grid is output, and a temperature time-varying curve is output based on a temperature drop calculation expression. According to the method, simulation calculation is carried out on typical working conditions, and production scheme simulation and risk assessment in an accident state of the oil pipeline in the permafrost region with very complex conditions are realized.

The invention provides an unconventional oil and gas reservoir heat-fluid-solid coupling numerical simulation method and system. The method comprises the steps that a multiphase numerical model of a coupling temperature field, a seepage field and a stress field is built; the multiphase numerical model is integrated with a Cahn-Hilliard equation, a heat conduction equation, a continuity equation, a Navier-Stokes equation and a mechanical equilibrium equation; determining a model computational domain of the multiphase numerical model; performing grid discretization processing on the model calculation domain and performing grid refinement processing on the peripheries of the mass flow inlet and the pressure outlet to obtain a plurality of grid units; inputting the environmental parameters and the initial condition parameters into the multiphase numerical model, controlling the multiphase numerical model to perform discrete calculation in each grid unit, judging whether a convergence condition is met or not, and if yes, updating the physical property parameters of the multiphase fluid according to the current temperature and pressure, and outputting a numerical simulation result of the unconventional oil and gas reservoir. According to the invention, the productivity prediction deviation can be reduced.

The invention relates to the technical field of oil and gas field development, and provides a method, device and equipment for analyzing the pressure drop of a serpentine well. The method comprises the steps that micro-arc section extraction and basic parameter setting are conducted on the serpentine well; according to the set basic parameters, micro-arc section flow characteristic analysis is conducted, and in combination with a fluid continuity equation and a momentum conservation equation, a serpentine well horizontal section single-phase pressure drop gradient prediction model is established; predicting pressure gradient data in the serpentine well by using the serpentine well horizontal section single-phase pressure drop gradient prediction model; and the serpentine well is set to adopt fixed bottom hole flowing pressure production, and the pressure drop of the horizontal section of the serpentine well is calculated by adopting a pressure drop superposition method according to the pressure gradient data in the serpentine well. According to the method, the influence of the geometrical morphology change of the shaft on fluid flow is effectively described, especially the continuous change of the gravity component along with the hole drift angle, and the inherent defect that a traditional model simplifies the shaft into horizontal flow is overcome.

The application discloses a method for calculating critical submerged water depth of a side-type water inlet based on a CSSS method. A point sink spherical critical surface model is constructed, and a conservation relationship between an effective working area and a radial flow velocity is established based on a continuity equation. For complex boundary working conditions, a dimensionless criterion is introduced to determine the effectiveness of the spherical assumption, and when the spherical assumption is invalid, an anisotropic ellipsoid correction is started, and a coordinate stretching equivalent method is used to calculate a limited effective area. A physical correction coefficient is constructed by using a potential flow geometric component and a dynamic loss component to replace pure statistical regression. A dynamic safety margin is calculated in combination with a vortex evolution time scale. The application solves the problem of prediction distortion of the critical water depth under a complex flow field, and improves the physical precision and operation safety of engineering design.

The invention relates to the technical field of fluid mechanics, and discloses a method for determining a volume evolution model of a Newtonian fluid liquid film under the action of shear airflow, and the method comprises the following steps: determining the thickness of the liquid film; determining an equilibrium equation based on set conditions; determining an expression of shear force of the liquid film surface according to the liquid film thickness and the liquid film surface speed; determining an expression of shearing force of the shearing airflow to the liquid film; substituting the two expressions into an equilibrium equation to obtain a liquid film surface velocity equation; determining a liquid membrane continuity equation and a liquid membrane internal velocity equation; substituting the liquid film internal velocity equation and the liquid film surface velocity equation into a liquid film continuity equation to solve the time evolution process of the liquid film, and obtaining differential equations of liquid film volume evolution under the action of uniformly accelerated shear airflow and uniform shear airflow, so as to construct a model; the model has high accuracy for the volume evolution rule of the Newtonian fluid membrane.

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 present invention relates to the technical field of filling mining. Disclosed are a filling pipeline resistance loss value calculation method, a product, a medium, and a device. The method comprises: providing a plurality of pressure sensors on a filling pipeline and acquiring detected pressure data; on the basis of the pressure data, determining the flow velocity of a fluid at each pressure sensor of the filling pipeline using a continuity equation and momentum equation of fluid mechanics; calculating the Reynolds number of the fluid at each pressure sensor on the basis of the flow velocity of the fluid at each pressure sensor; dividing the filling pipeline into a stable flow pipeline and an unstable flow pipeline by means of the Reynolds number, and calculating the length of the unstable flow pipeline; calculating the frictional resistance loss of the filling pipeline on the basis of the length of the unstable flow pipeline; and calculating the resistance loss value of the filling pipeline on the basis of the frictional resistance loss. The filling pipeline resistance loss value calculation method, the product, the medium and the device provided by the present invention can effectively improve the calculation accuracy of the resistance loss value of the filling pipeline.

The present invention provides a method for simulating the movement of typhoon-storm debris flow considering the spatiotemporal rainfall process, which iteratively performs the following calculations until the convergence condition is met: decomposing the average mud depth increment of the continuity equation into a mass flux term and a rainfall intrusion term, wherein: the mass flux term calculates the contribution of fluid movement to mud depth through divergence; the rainfall intrusion term is calculated through the spatiotemporal rainfall distribution function. q w Dynamically correct mud depth; calculate the volume concentration of the current time step based on the updated mud depth distribution, and dynamically correct the turbulent resistance coefficient of the rheological model through an exponential function according to the volume concentration; calculate the debris flow friction resistance based on the corrected rheological model, solve the momentum equation, drive the SPH particle motion, and output the spatiotemporal evolution results.

The invention discloses a pipe network pressure-speed coupling solving method based on an IDEAL algorithm, and the method comprises the steps: building a pipe network structure, and generating a staggered grid for each pipeline; speed equations of nodes in the pipeline and boundary nodes are obtained through the discrete momentum equation, and the pipe network speed equation is closed; a pressure equation of nodes in the pipeline is obtained through a continuity equation of pressure control volume, and closing of a pipe network pressure equation is achieved; solving the pressure equation for the first time, and substituting the obtained pressure into the speed equation to obtain an intermediate speed; solving the pressure equation for the second time to obtain the final pressure on the current level, and obtaining the final speed on the current level by utilizing the speed equation; and iteration is repeated until convergence pressure and velocity solutions are obtained. According to the method, by constructing equations of pipeline boundary points and pipe network connection points, closing of a speed equation and a pressure equation based on staggered grids is achieved, and coupling of pipe network pressure-speed information is promoted.

The application discloses a kind of construction method and system of gate control water network digital twinborn model, including using Preissmann four-point implicit difference format to the conversion of the continuity equation and momentum equation of St.Venant equation group;Channel water conveyance internal compatibility condition equation is constructed, and constant flow and non-constant flow equation in water network water conveyance are established, according to the external boundary condition of the water network channel set, calculate water network flow state;Internal compatibility condition equation is constructed at the branch point of water network, according to the internal compatibility condition equation of gate in water network channel, calculate the flow of regulating gate;The water network model of the application is compared and verified with physical model test, prototype observation experimental data, and further parameter adjustment is satisfied to water level flow accurate simulation requirement.The application accurately and practically reflects the running state of water network in virtual state space model, and can solve the state simulation and accurate prediction problem of gate control water network under various complex operating conditions.

The present invention provides a simulation method for a retaining ring structure in a chemical mechanical polishing process, comprising constructing a CFD model of the chemical mechanical polishing process, dividing a fluid region into discrete grids, wherein the grids are non-repetitive control volumes, and within each control volume, using a momentum equation, a continuity equation, and a VOF model to control the motion of the polishing liquid fluid, and a DPM model to control the motion of the abrasive, integrating the momentum equation, the continuity equation, and the VOF model for each control volume to obtain a discrete equation, solving the discrete equation to obtain simulation data, the simulation data including abrasive motion data, plotting the abrasive distribution and the abrasive aggregation state on the polishing pad and / or the wafer edge based on the abrasive motion data, and having the beneficial effects of visualizing the polishing liquid / abrasive flow through a finite element method, helping to understand the influence of the retaining ring on the polishing liquid flow, providing a retaining ring structure improvement to solve wafer edge over-polishing, conforming to actual production processes, and having high simulation accuracy.

This application relates to the field of gas transportation technology, and provides an equivalent inertia correction method and apparatus for a lumped parameter model of a gas pipeline. The method includes: generating a lumped parameter model of the gas pipeline based on the continuity equation and momentum equation of a one-dimensional compressible gas; generating an equivalent inertia factor based on the equation of state of a real gas under isothermal conditions; wherein the equivalent inertia factor characterizes the nonlinear sensitivity of the compressibility factor of the real gas to pressure; correcting the equivalent inertia of the lumped parameter model based on the equivalent inertia factor; and updating the boundary values ​​of the lumped parameter model after correction based on the fluid sound velocity under the current operating conditions of the gas pipeline and the pipeline length constraint when a system disturbance occurs. The method provided in this application effectively compensates for the inertial distortion caused by lumped averaging of material properties and solves the global phase shift problem under complex operating conditions.

The invention relates to a cavitation numerical simulation method based on consideration of a multiphase flow shear state, and the method comprises the steps: initializing basic parameters of a navigation body, the basic parameters including the shape, the length, the underwater navigation speed, the global cavitation number and the like; constructing a mathematical model based on the preprocessing matrix, wherein the mathematical model based on the preprocessing matrix comprises a continuous equation, a momentum equation, a component transport equation based on cavitation vapor phase volume fraction, a turbulence model equation and a cavitation model considering a multiphase flow shear state; constructing a flux calculation model adopting a windward format; constructing a grid for the wall surface of the navigation body; initializing flow field setting for the navigation body; and based on the basic parameters of the navigation body, the mathematical model based on the preprocessing matrix, the flux calculation model, the grid constructed for the wall surface of the navigation body and the flow field setting initialized for the navigation body, carrying out cavitation numerical simulation calculation on the navigation body.

The present application discloses a method and device for simulating water hammer in fracturing, which belongs to the technical field of fracturing and exploitation of oil and gas reservoirs. The simulation method includes: determining the simulated wellbore; establishing a water hammer continuity equation and a water hammer motion equation based on water head, flow rate and fluid density; then combining the liquid elasticity equation to establish a water hammer equation group, and solving to obtain the distribution equation of water head, flow rate and density; establishing a relationship between fluid pressure and density and flow rate, and setting up the water hammer equation group in parallel to obtain a water hammer simulation model; setting initial conditions and boundary conditions, and fitting to obtain a curve of water hammer pressure changing with time. The device includes a memory and a processor for storing a computer program, and the program includes the steps corresponding to the above method. The present application can more accurately simulate the water hammer pressure in the fracturing process, help developers use the water hammer pressure in the fracturing process to analyze the fracturing effect, thereby optimizing the fracturing parameters, obtaining a better fracturing effect, and promoting the efficient development of unconventional oil and gas resources.

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.

The application provides an unconventional oil and gas reservoir thermal fluid-solid coupling numerical simulation method and system, and the method comprises the following steps: constructing a multiphase numerical model coupling a temperature field, a seepage field and a stress field; the multiphase numerical model integrates a Cahn-Hilliard equation, a heat conduction equation, a continuity equation, a Navier-Stokes equation and a mechanical equilibrium equation; determining a model calculation domain of the multiphase numerical model; performing grid discretization processing on the model calculation domain and performing grid refinement processing on the periphery of a mass flow inlet and a pressure outlet, thereby obtaining a plurality of grid units; inputting environmental parameters and initial condition parameters into the multiphase numerical model, controlling the multiphase numerical model to perform discrete calculation in each grid unit, judging whether a convergence condition is met, if the convergence condition is met, updating physical property parameters of a multiphase fluid according to a current temperature and pressure, and outputting a numerical simulation result of the unconventional oil and gas reservoir. The application can reduce the production capacity prediction deviation.