128 results about "Continuity equation" patented technology

System and method optimize fluid dynamics modeling using a physics informed neural network (FINN) and a deep neural network (DNN). The DNN is trained to create a data driven mapping for invariants and Reynolds stress tensors associated with the fluid field based on simulation data. The FINN is trained using Navier Stokes and continuity equation based losses, using Reynolds stress tensor correction terms derived from the mapping and from invariants and tensors derived from estimated flow field variables. The FINN inputs include boundary conditions, and time-space coordinates for sampling points in the fluid flow field which describe time evolution of the turbulence problem depending on geometric bounds for the flow field.

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 belongs to the technical field of coupling algorithms, and discloses a smoothed particle dynamics-based warhead shell expansion fracture simulation method, which comprises the following steps of dispersing an explosive and a metal shell into SPH particles carrying physical information; calculating a correction matrix of a smooth function derivative of the SPH particle # imgabs 1 # according to the dispersed particle space position # imgabs 0 #; calculating the stress of the SPH particle # imgabs3 # at the spatial position # imgabs2 #; reconstructing the stress of an SPH particle # imgabs4 # and a neighborhood particle # imgabs5 # of the SPH particle # imgabs4 #; updating the density and the internal energy of the SPH particles at the spatial position # imgabs6 #; and the speed and the spatial position # imgabs8 # of the SPH particle # imgabs7 # are updated. According to the warhead shell expansion fracture simulation method based on smoothed particle dynamics, the reconstructed stress is introduced into the conservation equation, the continuity equation is corrected, on the premise that the speed continuity condition is guaranteed, the complex fracture problems such as warhead shell expansion fracture can be effectively solved, and the working efficiency of the warhead shell is improved. And the method has higher precision and robustness.

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 computational fluid mechanics and combustion science, in particular to a flame surface simulation method and device for supersonic combustion, and the method comprises the steps: solving a continuity equation, a momentum equation, a mixing fraction equation and an energy equation in a supersonic cold state mixing process; obtaining a mixing fraction distribution, a pressure distribution and a mixture total internal energy distribution; calculating a one-dimensional flame to construct a four-dimensional table of at least one mixing fraction-progress variable-oxidant side total internal energy-pressure based on the one-dimensional flame; and acquiring progress variable information of the supersonic combustion based on the four-dimensional table to obtain a flame surface simulation result of the supersonic combustion. According to the method, two control variables of pressure and oxidant side total internal energy can be introduced on the basis of a traditional small flame model according to the characteristics of supersonic combustion, and an Euler random field method is introduced to describe a joint probability density distribution function between the control variables, so that the influence of a preset probability density function is reduced, and the calculation precision is improved.

The invention provides a water consumption estimation metering method and system based on an intelligent fire hydrant and application of the water consumption estimation metering method and system. The method comprises the steps that an ideal water discharge model is established, and a basic calculation relation is determined through a Bernoulli equation and a continuity equation; secondly, an actual drainage model is constructed, factors such as pipeline inner wall roughness are considered, friction loss and local resistance loss are calculated according to a Darcy-Weistbach formula and a local resistance coefficient, a flow state is determined through a Reynolds number to determine a correlation coefficient, and then the drainage speed is corrected; and finally, comparing, verifying and optimizing the model by combining actual field data. According to the invention, the water consumption of the municipal fire hydrant can be estimated and metered without a flow meter, and a low-cost solution is provided for a water supply company to master illegal water consumption and distribution.

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 invention provides a modeling method for a flow model of an industrial dehydrogenation double-ring radial reactor, which comprises the following steps of: deducing the flow model of the industrial dehydrogenation reactor according to a modified momentum equation, an Ergun equation and a continuity equation, and simulating fluid mechanics behaviors of reactant flow in a main runner and a catalyst bed layer; a modeling method for solving the mathematical model of the double-ring radial reactor by adopting a numerical algorithm; a numerical algorithm is adopted to solve a mathematical model of the double-ring radial reactor, accurate mathematical description of fluid mechanics behaviors in the industrial dehydrogenation reactor is achieved, and quantitative reference is provided for optimization selection of the structural size of the industrial double-ring radial reactor on the basis. A newly-built industrial dehydrogenation reactor based on the method can realize more balanced utilization of the catalyst at different parts, so that the treatment capacity of the dehydrogenation reactor and the overall utilization efficiency of the catalyst are 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 invention discloses a water hammer analogue simulation method and device for fracturing, and belongs to the technical field of oil and gas reservoir fracturing exploiting.The simulation method comprises the steps that a simulated shaft is determined; establishing a water hammer continuity equation and a water hammer motion equation based on the water head, the flow, the fluid density and the like; establishing a water hammer equation set by combining a liquid elastic equation combination, and solving to obtain a distribution equation of the water head, the flow velocity and the density; establishing a relational expression of fluid pressure, density and flow, and establishing a water hammer equation set in parallel to obtain a water hammer simulation model; initial conditions and boundary conditions are set, and a curve of water hammer pressure changing along with time is obtained through fitting. The device comprises a memory for storing a computer program and a processor, wherein the program comprises the steps corresponding to the method. According to the method, the water hammer pressure in the fracturing process can be more accurately simulated, developers are helped to analyze the fracturing effect by using the water hammer pressure in the fracturing process, so that fracturing parameters are optimized, a better fracturing effect is obtained, and efficient development of unconventional oil and gas resources is promoted.

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 method for predicting flow velocity and Reynolds stress transverse distribution in a vegetation riverway, and belongs to the technical field of hydraulics and river dynamics, and the method comprises the steps: determining a two-dimensional longitudinal flow velocity transverse distribution control equation with average water depth; dividing the riverway into a vegetation area and a non-vegetation area along the direction vertical to water flow by taking the center position of the boundary of the upstream end of the non-submerged vegetation community as an original point; determining a water depth average longitudinal flow velocity transverse distribution analysis model of the vegetation area and the vegetation-free area; providing boundary conditions of the analytical model and solving to obtain transverse flow velocity distribution of each cross section; and constructing a Reynolds stress transverse distribution prediction model based on the predicted flow velocity transverse distribution, and predicting the Reynolds stress transverse distribution. According to the method, the control equation of the flow velocity transverse distribution in the vegetation riverway is deduced from the water flow momentum equation and the continuity equation, solving is carried out according to boundary conditions, and prediction of the flow velocity transverse distribution and Reynolds stress transverse distribution of each cross section is achieved.

This invention presents a projection embedded discrete fracture model integrating a TPFA and MFD hybrid approach, creating a pEDFM framework for various anisotropic two-phase flow situations. It specifies the distribution of extra pressure freedoms on matrix grids for MFD implementation, maintains f-f connections in TPFA through a standard pEDFM workflow, and introduces a low-conductivity fracture treatment for MFD. It also outlines the derivation of numerical flux calculation formulas for effective m-m and m-f connections. The mixed TPFA-MFD design applies to numerical flux estimation across both K-orthogonal and non-K-orthogonal grids, enhancing computational efficiency and facilitating the spatial discretization of continuity equations for matrix and fracture grids under anisotropic permeability conditions. A global equation system is formulated based on the continuity of effective connections, with time discretization via the implicit backward Euler method and pressure and water saturation distributions determined by a Newton-Raphson based nonlinear solver.

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 discloses a method for inverting the joint stiffness in a rock mass based on reflected waves. The strain-time curve of the incident wave and the strain-time curve of the reflected wave passing through the left side of the joint are obtained by an ultra-dynamic strain meter, and are respectively converted into a series of incident harmonics and a series of reflected harmonics of frequency domain angles by discrete Fourier transform, and the reflected harmonics corresponding to each frequency are divided by the incident harmonics. According to the continuity equation and Hooke's law, as well as the linear displacement discontinuous boundary conditions when the stress wave passes through a linear deformation joint, the function expression of the reflection coefficient R when the stress wave is normally incident through a single linear deformation joint can be derived, and the size of the unknown joint stiffness kn can be fitted. The present invention can determine the joint stiffness of the joints inside the rock rod only through the strain change curve at a certain point before the joint: the time domain waveform diagram of the incident wave and the reflected wave, avoiding the drilling and coring measurement of the rock rod. The operation steps are simplified and the calculation accuracy is improved.

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.