201 results about "Fluid modeling" patented technology

A very simple model has been presented which is able to reproduce slug flow from the instability of a flow with average hold-up and slip. The disclosure demonstrates that slug flow may be modeled as two different, stable solutions to the multiphase flow which coexist at different points in the line, moving with a celerity of UG. By using a white-noise inlet condition which preserves the average hold-up in the pipeline, a series of stable slug and stratified regions can be created without any need to resort to a Lagrangian slug tracking scheme. A quite good fit to field data was obtained with minimal effort by adjusting the slip relation. At present, the model merely demonstrates a potential, very attractive, flexible, and easy-to-implement alternative to Lagrangian slug tracking.

The invention belongs to the field of environment protection, and in particular relates to an optimization design method of an anaerobic continuous flow agitator bath type biological hydrogen production reactor. The method comprises the following steps: researching reactor internal flow field characteristics of different types of stirring paddles under the conditions of different paddle-bath diameter ratios and different agitating speeds and influence on hydrogen production process, by using a numerical simulation software based on computational fluid mechanics technology; obtaining detailed flow field information, such as velocity field, turbulence energy and dissipation rate thereof, biogas integration rate and shearing rate distribution by adopting a two-phase flow model, and analyzing and comparing different flow field information obtained through simulation according to influence on hydrogen production process by the various flow field information, thereby determining an optimal stirring paddle style and agitating speed combination, and providing an effective method for the optimization design of the agitator bath reactor. The optimization design method of the anaerobic continuous flow agitator bath biological hydrogen production reactor is mature in technology, avoids the blindness of hydraulic design of the reactor using an empirical or semiempirical association method, and has the advantages of being visual in optimization cycle effect and short in optimization cycle, saving cost, and the like.

The invention aims to disclose a method for constructing a turbulence model by a spatial filtering method. By simulating full-channel turbulence of an axial-flow pump of the turbulence model, corresponding flow details can be obtained, flowing in all flow passage components can be qualitatively recognized, the energy and cavitation performance of the axial-flow pump can be estimated quantitatively according to a calculation result, and the mechanisms of important hydraulic characteristics such as hydraulic cavitation, hydraulic vibration and the like are disclosed, so that theoretical and technical basis is provided for researching and developing a water pump or a water turbine device with high performance, large flow and a high water head and the aim of the invention is fulfilled.

The invention discloses a reactor primary loop coolant flow field, temperature field and stress field coupling calculation method. The method comprises the following steps: 1) constructing a high-temperature gas cooled reactor core model and a steam generator model with the same size as actual equipment; 2) establishing a computational domain 1, a computational domain 2 and a computational domain3; 3) setting equipment materials and fluid domains in the computational domain 1, the computational domain 2 and the computational domain 3; 4) setting areas and boundary layers of a flow field, a temperature field and a stress field; 5) meshing the flow field, the temperature field and the stress field; 6) adopting a k-epsilon turbulence model in the computational domain 1 and the computationaldomain 3, and adopting a porous medium model in the computational domain 2; 7) obtaining flow field, temperature field and stress field distribution results of the computational domain 1, the computational domain 2 and the computational domain 3, and 8) obtaining optimal operation parameter configuration of the high-temperature gas cooled reactor at different power levels. The method can realize coupling numerical simulation calculation of the coolant flow field, the temperature field and the stress field of a reactor primary loop.

The invention discloses a microgrid flow model suitable for various operation modes, and a calculation method. The invention discloses a flow calculation method suitable for microgrids in various operation modes, and the method comprises the steps: forming five types of microgrid operation modes and four types of nodes according to two types of basic operation modes and three types of control strategies of a microgrid; enabling the microgrid flow calculation in five types of different operation modes to be divided into two types of flow calculation; building a unified flow model; and proposing an LM-TR (Levenberg Marquardt method combined with trust region technique, LM-TR) flow algorithm for solving. The method does not need the jacobian matrix of a flow equation to be nonsingular, has global convergence, is small in dependence on initial values of unknown variables, effectively improves the convergence of flow calculation, and can solve a problem that the convergence of flow calculation of a microgrid system is difficult because that the jacobian matrix is singular or there is no balance point. Moreover, the method can process various types of nodes conveniently, and can solve a problem of the diversity of microgrid flow calculation in different operation modes. The method is suitable for the flow calculation of the microgrid in various operation modes, and is good in engineering application value.

The invention discloses a viscous fluid modeling method based on SPH method approximate solution. An N-S equation is firstly simplified according to the characteristics of a particle system method; then, according to the simplified equation, a framework for simulating a viscous fluid is built; and then, according to the simulation framework, each physical quantity is subjected to approximate solution based on an SPH method. a corresponding pressure term in the N-S equation is solved approximately through a pressure-density method, and the problem that strict time step constraints exist when the SPH method simulates the viscous fluid is solved; and besides, the phenomenon of particle clustering in a fluid motion process is solved. Through building a spring model, that is, adding, modifyingand deleting springs between adjacent particle pairs, viscoelasticity of the fluid motion is realized; and through influences on the relative velocity of particles by introduced temperature, influences on the fluid viscosity by the temperature are thus described. Compared with the traditional method, the method of the invention has the advantages that the calculation is simple; real-time simulation can be realized basically; and the viscous fluid motion scene can be simulated more vividly.

The invention provides a simulation method for the flow field and convection / radiation coupling heat transfer of a multi-nozzle rocket. Firstly, a three-dimensional model of the multi-nozzle rocket isestablished. Secondly, the multi-block structured mesh method is used to mesh the three-dimensional model. The mathematical model of plume field and convection heat transfer of multi-nozzle rocket isestablished again. S multicomponent equation is discretized and integrated by AUSM + scheme. The inviscid flux at the boundary of the model is obtained by differentiation. Then the improved radiationmodel DOM is opened to obtain the radiation absorption coefficient of the model: the integral of radiation heat transfer by DOM model. Differential fundamental equation discretization; The radiationintensity values of each point are obtained; Finally, use RNG k-Epsilon turbulence model, output Mach number, temperature, pressure flow field and convection / coupled heat flux cloud map; The method ofthe invention can not only improve the calculation accuracy but also reduce the calculation cost, and the calculation result can provide guiding significance for the thermal protection of the bottomof the rocket.

A spray injection analysis and nozzle configuration system is described having a user input unit that collects spray system input parameters and relays the collected parameters to a fluid performance matching unit and / or problem geometry unit for subsequent processing. The user inputs basic system parameters, including the desired spray fluid characteristics, to obtain suggested system configuration, including spray nozzle types and quantities. Accuracy of suggested spray nozzle type and configuration is increased via approximating the viscosity and / or surface tension parameters of the desired spray fluid with that of collected performance data. When a user already knows the desired spray nozzle type and associated system parameters, the user input unit routes this information to the problem geometry unit for creation of a problem geometry file, including calculation of the drop size distribution and spray velocity, and performance modeling via the fluid modeling unit.

The invention provides a method and device for calculating the virtual energy storage capacity of a heat / cold supply system and electronic equipment; the method comprises the steps: building a heat flow model of the system according to the structure of the heat / cold supply system; according to the real-time measurement information of the heat / cold supply system, determining the real-time operation state information, and solving a heat flow model of the heat / cold supply system; according to the solving result of the heat flow model, determining the running states that the virtual energy storage amount of the heat / cold supply system is zero and the virtual energy storage amount is full, and calculating the instantaneous energy storage power limit and the instantaneous energy discharge power limit; under any preset adjustment duration, based on the real-time operation state information of the heating / cooling system, solving and optimizing a heat flow model of the heating / cooling system according to the upper limit constraint condition and the lower limit constraint condition of the heat transfer fluid temperature in the pipe network and the indoor temperature of the user side; and obtaining the average energy storage power limit, the average energy release power limit, the energy storage capacity and the energy release capacity of the heat / cold supply system under the adjustment duration according to the optimization result.

The invention relates to the simulation method and apparatus used in plasma modeling. It includes a method to transform transient formulations of the phenomenological plasma model into a quasi-stochastic spatial formulation. Specifically, the invention aids in decreasing computational time for the modeling of plasma in a plasma processing system, particularly those involving two different time-based parameters. The invention is particularly described in connection with plasma simulations used for the optimization dual-frequency capacitively-coupled plasma etching systems.

The invention discloses a hypersonic velocity blunt front edge streaming turbulent kinetic energy inlet boundary setting method, which comprises the following steps of S1, calculating a basic flow field, and obtaining a steady basic flow field variable; S2, performing direct disturbance wave simulation by using a numerical simulation system to obtain an unsteady flow field variable; S3, analyzing the flow field to obtain a disturbance field [phi]', and obtaining turbulent energy distribution characteristics; S4, setting a turbulent energy inlet boundary; and S5, calculating turbulence / transition and the like. According to the method, the turbulent energy equation in the turbulence model does not need to be modified, the calculation deviation of the turbulent energy equation at the shock wave downstream can be avoided by setting the inlet boundary condition, the more accurate turbulent energy inlet boundary condition is set based on a direct numerical simulation result, and the method has the advantages of reasonable calculation result, high realizability and high reliability, and can be popularized to three-dimensional flow conditions and the like.

The invention discloses an oil-water two-phase non-Darcy seepage numerical simulation method based on a discrete fracture model, and the method comprises the steps: determining an oil-water two-phaseseepage mode, and selecting a low-speed non-Darcy seepage model in a fracture system; selecting a low-speed nonlinear seepage model in the matrix for characterization; establishing continuity equations of an oil phase and a water phase respectively according to the law of conservation of mass; discretizing the continuity equation, and establishing a numerical simulation model; correcting the numerical simulation model by using an embedded discrete fracture model, adding a variety of non-adjacent link information, and establishing a nonlinear equation system; solving the nonlinear equation system to obtain oil-water two-phase pressure and saturation parameters; establishing a water-oil displacement model under a complex fracture condition, performing numerical simulation, and analyzing output characteristics of an injection well and an oil production well. The problem that an existing commercial numerical simulation method cannot simulate two-phase low-speed non-darcy flow in a matrix is solved, and the method has obvious advantages in the aspects of calculation precision and calculation efficiency.

The invention discloses a numerical prediction method for the size of bubbles in a gas-liquid multiphase pump, and the method comprises the following steps: 1, obtaining the final shapes of an impeller and a guide vane through the three-dimensional inverse problem design of the gas-liquid multiphase pump; 2, establishing a three-dimensional geometric model of the gas-liquid multiphase pump according to the step 1; 3, according to the geometric model in the step 2, carrying out full-flow-channel hexahedron structure grid division, and improving the grid quality by adopting different types of topological structures; 4, establishing a bubble size prediction model which comprises a basic control equation, a turbulence model and a bubble equation; 5, based on the bubble size prediction model inthe step 4, setting boundary conditions and solving parameters by adopting simulation calculation of computational fluid dynamics CFD, and carrying out numerical prediction on the bubble size and thegas-liquid two-phase flow field in the multiphase pump; and 6, carrying out post-processing analysis on the numerical calculation prediction in the step 5 to obtain a bubble size change rule in the impeller and the guide vane of the multiphase pump and gas-liquid two-phase flow field information.

The invention discloses a hyporheic exchange influence factor sensitivity analysis method based on orthogonal experimental method. The method specifically comprises the following steps: firstly constructing a two-dimensional sand slope upper surface water-underwater exchange mathematical model based on Reynolds average N-S equation and k-Omega turbulent model, wherein the model comprises a two-dimensional sand porosity water flow steady movement equation, and establishing a solute migration model; and then setting a boundary condition for the surface water-underwater exchange mathematical model; and finally solving the surface water-underwater exchange mathematical model by adopting the orthogonal experimental method, taking the time consumed for changing the monitoring domain point soluteconcentration to the balance as an evaluation index of the sensitivity analysis, thereby analyzing the surface water-underwater exchange mathematical model and solute movement model parameter sensitivity. The problem that the prior art is large in hyporheic exchange sensitivity analysis workload and difficult to implement is avoided.

The invention discloses a spawning site positioning inversion simulation method based on drifting roe embryo development time. The method comprises the following steps of collecting roes at a preset detection position; identifying the development time of the collected roes to obtain the drifting time of the roes; establishing a gridding two-dimensional water flow model, and calculating the flow velocity of each grid node in the two-dimensional water flow model; and based on the flow velocity of each grid node in the two-dimensional water flow model and the drifting time of the roes, taking each collected fish roe motion as a simulation object to carry out inversion calculation, thereby realizing positioning of the spawning site. According to the method disclosed by the invention, the waterflow is gridded based on the two-dimensional water flow mathematical model, so that the flow field distribution of the water flow is calculated, and then the position of the fish spawning site is deduced and positioned according to the collection position and the drifting time of the fish roes. Compared with the mode that water flow is regarded as constant-speed fluid in the prior art, the difference of water flow speeds at different positions is considered, so that the positioning accuracy of the fish spawning site is greatly improved.

The invention discloses a turbulence field updating method. The method comprises the steps of obtaining sample turbulence data; carrying out model training by utilizing the sample turbulence data to obtain a reinforcement learning turbulence model; calculating to obtain initial turbulence data of the turbulence field through an RANS equation; processing the initial turbulence data through the reinforcement learning turbulence model to obtain predicted Reynolds stress; calculating the predicted Reynolds stress through the RANS equation to obtain updated turbulence data; according to the turbulence field updating method, the calculation precision can be effectively improved, and more accurate turbulence field updating is realized. The invention further discloses a turbulence field updating device and equipment and a computer readable storage medium, which all have the above beneficial effects.

A spray injection analysis and nozzle configuration system is described having a user input unit that collects spray system input parameters and relays the collected parameters to a fluid performance matching unit and / or problem geometry unit for subsequent processing. The user inputs basic system parameters, including the desired spray fluid characteristics, to obtain suggested system configuration, including spray nozzle types and quantities. Accuracy of suggested spray nozzle type and configuration is increased via approximating the viscosity and / or surface tension parameters of the desired spray fluid with that of collected performance data. When a user already knows the desired spray nozzle type and associated system parameters, the user input unit routes this information to the problem geometry unit for creation of a problem geometry file, including calculation of the drop size distribution and spray velocity, and performance modeling via the fluid modeling unit.

The invention provides a component prediction method combining machine learning and CVD modeling. The method comprises the following steps: determining the size of a reactor and the shape and size ofa substrate; establishing a corresponding reactor geometric model; adding material attributes to the geometric region and the boundary; carrying out model mesh generation; selecting to establish a multi-physical field model, and carrying out multi-physical field coupling; establishing a fluid heat transfer and laminar flow model; establishing a concentrated substance transfer model; calculating aphysical field of laminar flow and fluid heat transfer coupling, and calculating a physical field interface of chemical and concentrated substance transfer by taking the obtained solution as an initial value to obtain concentration distribution of various intermediate substances obtained by reaction of the boron-carbon system precursor gas; respectively obtaining different results for contrastiveanalysis, and finally obtaining substance concentration distribution results under various deposition process conditions; a machine learning algorithm is utilized to associate the deposited boron-carbon ratio with the boron-carbon ratio, the boron-carbon ratio deposited under different deposition conditions is predicted, and the error is analyzed. The method can accurately predict the component ratio of the deposition product.

The invention discloses an EIT tomography-based different fluid model identification and pipe blocking positioning method, which comprises the following steps of: 1, applying electric excitation to afluid conveying pipeline, measuring to obtain a boundary voltage sequence, and processing the measured boundary voltage sequence by a computer to obtain an EIT image; 2, inputting the EIT image into aTensorflow fluid model identification network by the computer, and identifying a core flow model, a laminar flow model, a bubble flow model and a circulation model; 3, the computer calculates the minimum error value of each fluid model; 4, the computer calls a fluid model optimization module to optimize the fluid model to obtain an optimized reconstructed image of each fluid model; Fifthly, the blocked pipe blocks are positioned through a computer; and sixthly, the computer judges the pipe blocking degree. The pipe blocking device is novel and reasonable in design, capable of accurately positioning in real time and judging the pipe blocking degree, capable of improving the conveying efficiency and reducing the conveying cost, high in practicability and convenient to popularize and use.

The invention provides a parallel grid simulation method for an aero-engine combustion chamber through-flow mode, complete depiction of a geometric structure of a combustion chamber air inlet bucket in through-flow calculation can be realized and fidelity of numerical simulation of an aero-engine combustion chamber is ensured. For a meridian plane where the combustion chamber air inlet hopper is located, the meridian plane corresponds to the inner space and the outer space of the air inlet hopper. The flow structures in the two spaces are completely different, and the same solving mode cannotbe adopted. Therefore, firstly, a control equation of through-flow calculation is obtained through derivation, and through-flow items which need to be processed independently and are caused by the special structure of the combustion chamber air inlet hopper are clarified. Secondly, the internal flux and the external flux of the air inlet hopper are calculated by utilizing a parallel grid method, and further completing the depiction of the internal and external gas flow of the air inlet hopper and the mixing physical process of the air inlet hopper in the through-flow model. The method has certain guiding significance and engineering practical value for improving the precision of the through-flow model for numerical simulation of the combustion chamber of the gas turbine.

The invention relates to a single-phase fluid network modeling method. The method comprises the following steps: according to single-phase fluid characteristics, establishing a branch model of a single-phase fluid network; according to a mass conservation law of a single-phase fluid network node, establishing a node model of the single-phase fluid network; according to the branch model of the single-phase fluid network, establishing a node pressure equation of the single-phase fluid network; solving the node pressure equation by adopting an improved Gaussian elimination method and a Gauss-Seidel iteration mixed algorithm, and calculating the pressure of the single-phase fluid network node; according to the branch model and the pressure of the single-phase fluid network node, calculating the flow of each branch; and according to the pressure of the single-phase fluid network node and the flow of each branch, establishing a mathematic model of the single-phase fluid network. The mathematic model of the single-phase fluid network, obtained with the single-phase fluid modeling method, can reflect a practical operational condition of the single-phase fluid network accurately in real time.

The invention discloses a method for constructing real-time visual fluid in a complex three-dimensional pipe network, which comprises the following steps of: analyzing and concluding various pipelinesand intersections in the complex three-dimensional pipe network, obtaining pipe network center line data through pipe network modeling and center line acquisition, and determining the types of the pipelines and the intersections; For various pipelines and intersections, methods of intersection operation, pipe network bottom surface reconstruction and the like are adopted to establish a fluid surface model so as to reduce the real-time fluid modeling calculation amount. The fluid surface and the fluid depth are updated in real time based on real-time fluid depth information obtained through asensor network or numerical simulation and the pipe network model category, and real-time fluid modeling is achieved; And finally realizing real-time visualization of the fluid under the complex three-dimensional pipe network scene by adopting a rendering technology. Taking mine water inrush as an example, the feasibility of the method is verified, and visual analysis is carried out. The problem that real-time visualization of fluid in a complex three-dimensional pipe network is difficult to achieve is solved.

The invention discloses a nuclear facility near-field environment simulation numerical wind tunnel establishing system and method, and the system comprises a preprocessing module which is used for setting boundary conditions and experiment conditions through a GUI interface, importing and processing a geometric model of a numerical wind tunnel simulation object, setting grid parameters, and automatically generating a grid; a CFD solver module which is used for realizing steady-state model solving, isothermal or non-isothermal model solving, multi-component transfer model solving and Lagrange particle model solving, considering the influence of buoyancy and lifting force and providing various turbulence models; a numerical wind tunnel simulation module which is used for selecting a corresponding turbulence model based on the preprocessing module and the CFD solver module and performing numerical wind tunnel simulation on near-field atmospheric diffusion of the nuclear facility to obtaina simulation result; and a post-processing module which is used for automatically extracting various types of data in the simulation result and carrying out visual output. Based on the CFD principle,a proper air turbulence model is selected, and nuclear facility near-field atmospheric diffusion can be accurately simulated.

The invention provides a turbulence model for numerical simulation of vortex-induced vibration of a rigid cylinder. The model is based on a low Reynolds number k-epsilon (LSKE) turbulence model of Launder and Sharma; referring to a limiting method of a turbulence energy generation item of the SST k-omega turbulence model, turbulence energy generation items of a near-boundary region and a wake flowfield of the flow field are respectively limited, meanwhile, the turbulence energy generation items and dissipation items of different regions in the flow field are corrected through a correction function, and a turbulence model suitable for numerical simulation of vortex-induced vibration of a rigid cylinder in a subcritical Reynolds number range is established. Compared with an existing turbulence model, the turbulence model has the advantage that the calculation precision is greatly improved on the premise that the calculation speed is guaranteed in the numerical simulation of the vortex-induced vibration of the rigid cylinder.

The invention relates to a turbulence model correction method suitable for moving boundary streaming, and belongs to the technical field of hydraulic machinery. The method comprises steps of defininga filtering function fFBM through a vortex structure judgment criterion; dividing the flow field into a vortex region and a non-vortex region based on the filter function fFBM, determining the vortexregion when the vortex structure judgment criterion is greater than or equal to a set threshold A, and determining the non-vortex region when the vortex structure judgment criterion is less than the set threshold A; multiplying the vortex viscosity coefficient mu t of the turbulence model of the vortex region by the dynamic correction coefficient fv, keeping the vortex viscosity coefficient mu t of the turbulence model of the non-vortex region in the original expression, and substituting the vortex viscosity coefficient into the turbulence model equation again to solve the flow field. According to the method, a vortex structure is adopted as a filtering scale, numerical prediction simulation is associated with flow field information, the influence of the dynamic boundary on the vortex viscosity coefficient of the turbulence model is considered, and the streaming prediction precision of the dynamic boundary is greatly improved.

The invention discloses a mortise broaching process simulation analysis method based on thermal force flow multi-field coupling. The method comprises the steps of creating a broaching thermal force model according to the sizes of a cutter and a workpiece, material related parameters, cutting related parameters and heat conduction characteristics, and making analog simulation; establishing a broaching heat flow model according to the cooling related parameters of the cutter, the workpiece and the cooling liquid, and performing analog simulation; and coupling the simulation results of the broaching thermal force model and the broaching thermal flow model to obtain a broaching thermal force flow multi-field coupling model, and simulating the cooling effect of the cooling liquid on the workpiece, the cutter and the cuttings in the broaching process. The thermal force and thermal flow simulation analysis model in the broaching process is established, a data transmission platform among the models is established, coupling simulation analysis among three fields of broaching thermal force flow is achieved, the flow speed, temperature and impact pressure of cooling liquid are fully considered, and simulation precision is greatly improved.

The invention discloses a henhouse ventilation simulation method and electronic equipment applying the method. The simulation method comprises the following steps: acquiring geometric and physical information of a henhouse to be simulated; determining a control equation; establishing a three-dimensional physical model and dividing calculation grids; determining a spatial discretization method; determining calculation reference conditions and methods; defining material characteristics; determining a turbulence model and a near-wall flow processing method; defining surface boundaries and regionconditions; setting solving control parameters; initializing solving parameters; setting a residual error limit value and a monitoring parameter; solving a control equation, judging convergence, entering the next step if the convergence occurs, and otherwise, returning to the second step; displaying and outputting computational results. According to the method, consideration factors are comprehensive, the simulation degree is high, hardware requirements are low, the calculation speed is high, the speed, pressure, temperature and pollutant concentration distribution information in the henhousecan be known in detail, and the henhouse ventilation design level and energy utilization efficiency are improved.

The invention discloses a novel non-Newtonian fluid micro-coating system, which comprises a non-Newtonian fluid material loading mechanism, a fluid modeling unit and an intelligent feedback coating control unit, wherein the non-Newtonian fluid material loading mechanism comprises a material storage pressure barrel internally provided with a pressure regulating valve, and an ejector pin valve typenozzle connected by means of a feeding pipeline; the pressure regulating valve controls the air pressure of the material storage barrel, and the fluid can be pressed into a feeding pipeline and then sprayed out by means of the nozzle; the fluid modeling system is responsible for performing process analysis on non-linear characteristics of the non-Newtonian fluid and dynamically modeling a micro-coating process; the intelligent feedback coating control system comprises an upper computer, a signal input module, a controller, a controlled object module, a detection unit and an execution module, and is responsible for performing feedback control on the flow velocity of pipeline fluid based on a non-Newtonian fluid model. The novel non-Newtonian fluid micro-coating system solves the problem that feedback control is not carried out according to fluid nonlinear features in the existing micro-coating process, and can be applied to various surface coating processes such as paint spraying and fluorescent powder glue coating.