31results about How to "Accurate boundary conditions" patented technology

The invention provides a coronary blood-flow volume acquiring method. The coronary blood-flow volume acquiring method comprises acquiring coronary image information to acquire coronary geometrical characteristic data; according to the coronary geometrical characteristic data, acquiring the total volume V of a coronary reference lumen, and calculating the blood-flow volume Q of an coronary openingaccording to a following formula, wherein, when the unit of Q is mm3 / s and that of V is mm3, K ranges between 5 and 9.5. The invention also provides a coronary blood-flow speed acquiring method. According to the coronary blood-flow volume and speed acquiring method, the coronary blood-flow volume and speed can be acquired through the coronary image information; compared with a method for estimating coronary blood-flow volume according to myocardium size in the prior art, the coronary blood-flow volume and speed acquiring method can provide more accurate boundary conditions for image-based hamodynamic calculation.

The invention relates to the field of aircraft structure strength calculation, in particular to a boundary condition iteration method based on progressive failure of structural damage, so as to solve the problems that the operation of extracting a boundary condition from an overall model and applying the boundary condition to a detail model in a calculation process of progressive failure of structural damage wastes time and energy, and the boundary condition is inaccurate gradually with an increase in damage. The boundary condition iteration method based on progressive failure of structural damage comprises the following steps: automatically extracting the boundary condition; establishing the detail model; and performing iterative solving on a constraint condition. According to the method, the change of the boundary condition caused by factors such as gradual damage extension, degeneration of material performance, rigidity and the like, and the like is fully considered, so that the boundary condition is more accurate; and in addition, the calculation process is repeatedly iterated in a full-aircraft model and the detail model, so that the calculation precision is greatly improved and the result accuracy is higher.

The invention provides a device and method for measuring the excitation force of the camshaft to the cam bearing cap. The device is based on the existing cam bearing cap and is divided into internal components and internal components, and the horizontal and vertical The pressure sensing plate is installed in the direction, the two sides of the horizontal pressure sensing plate are respectively in contact with the plane of the inner and outer members, and the vertical pressure sensing plate is pre-tightened on the top of the inner member through the adjusting bolt on the top of the outer member. The components and adjusting the positional relationship between the bolt and the pressure sensing plate ensure that the excitation force of the camshaft is accurately transmitted to the pressure sensing plate; the method uses the excitation force generated by the measuring device on the camshaft in horizontal and vertical Acquisition is carried out, and according to the calibration relationship, the signal output by the pressure sensing plate is converted to obtain the force data. The invention can accurately measure the horizontal and vertical forces of the cam bearing cover respectively, so as to accurately reflect the excitation force of the camshaft on the cam bearing cover.

The invention discloses a test determination method for a friction coefficient of a contact surface of a bearing cap and a bearing pedestal. First a test device comprising connection bolts, the bearing cap and the bearing pedestal is mounted; the connection bolts are loaded for a test; loaded bolt pump pressure and related data of the opening amount of two sides of the bearing cap corresponding to the bolt pump pressure are measured and recorded; corresponding relationships between the bolt pump pressure and the expanding volume in a test result are obtained; analogue simulation calculation under different friction coefficient preset values is carried out on the loading processes of the connection bolts by employing a finite element method, and the corresponding relationships between the bolt pump pressure and the corresponding the opening amount of two sides of the bearing pedestal under the friction coefficient preset values in a simulation result are obtained; a scatter diagram for the relationships of the opening amount of two sides of the bearing cap and the bolt pump pressure is made according to the test result and the simulation result; and the simulation result and the test result are compared, and the friction coefficient of the contact surface of the bearing cap and the bearing pedestal is determined according to the closest data. According to the method, the friction coefficient of the contact surface of the bearing cap and the bearing pedestal that better satisfying a practical structure can be obtained; a more precise boundary condition is provided for strength check of the complete machine, and the research and development cycle is shortened.

The invention discloses a calculation method for the concentration distribution of radioactive gas diffused in underground rock mass, comprising the steps of: 1) modeling the underground cavern mountain body, and obtaining the water level distribution through two-dimensional saturated-unsaturated seepage analysis; 2) solving the unstable 3) Calculate the diffusion coefficient, adsorption coefficient and absorption coefficient of radioactive gas in the cracked air of underground rock mass, and analyze the half-life of radioactive gas; 4) Establish the two-dimensional unsteady diffusion equation of the radioactive gas in the underground rock mass; 5) Solve the two-dimensional diffusion equation of the radioactive gas in the underground rock mass above the groundwater level to obtain its concentration distribution. The diffusion model of radioactive gas in underground rock mass is established, which can systematically, scientifically and accurately calculate the concentration distribution of radioactive gas in underground rock mass, and provide theoretical support for the prevention and control of radioactive pollution in underground nuclear facilities.

The invention relates to a method for inversion of non-uniform mechanical parameters of rock based on DSCM-FEMU. Based on the digital speckle correlation method, the deformation of the specimen during the rock loading experiment was observed, and the strain field was calculated; based on the finite element model correction method, the numerical calculation model of the experimental loading was established in ABAQUS, and the initial elastic parameters of each element were given, using Python The program assigns the elastic parameters of each element based on the Weibull distribution, performs finite element calculation, and automatically outputs the stress field of the numerical model through the Python program; based on the finite element theory, the inversion objective function of the non-uniform mechanical parameters of the rock is deduced, representing the strain field measured by the experiment. Using the optimization algorithm to minimize the objective function and output the most matching elastic parameters of each element, if the objective function does not meet the iterative convergence conditions, the elastic parameters of each element are automatically modified through the Python program, and the new elements are substituted. In one round of finite element calculation, until the objective function converges, the elastic parameters of each element are output.

The invention discloses a method for simulating the surface heat transfer coefficient of a metal additive formed part based on heat flow coupling, which includes the following steps: (1) using a three-dimensional drawing software to prepare a geometric model of the printed part and the flow field around the printed part and perform finite element analysis; (2) ) Assign corresponding material properties to the geometric model; (3) Use tetrahedral mesh division for the geometric model; (4) Establish a heat transfer analysis module for solving the temperature field in the process of metal additive printing; (5) Establish a module for Volume heat source module for simulating the laser heating process in metal additive printing; (6) Establish a fluid analysis module for solving the flow field model in the metal additive printing process; (7) Set the solution time and solve the temperature field and flow field at the same time Get the surface heat transfer coefficient. The surface heat transfer coefficient of the printed part obtained by the present invention provides accurate boundary conditions for numerical simulations (such as heat flow simulations and thermal simulations) related to additive manufacturing, so that the numerical simulation results are accurate.

The invention discloses a coupling calculation method of one and two circuits of a nuclear power system. The steps are as follows: 1. Establish a three-dimensional geometric model of a reactor steam generator and divide the grid, and establish a one-dimensional simplified model of a nuclear reactor one and two circuits; 2. Use a calculation fluid The dynamics software sets the initial boundary conditions of the geometric model of the steam generator and the initial state of the calculation domain; 3. The computational fluid dynamics software calculates the steam generator model, obtains the calculation results, and transfers the calculation results to the system analysis program as a system analysis The boundary conditions of this time step of the program; 4. The system analysis program calculates the first and second loop models, obtains the calculation results, and transmits the calculation results to the computational fluid dynamics software as the calculation time of the next time step of the computational fluid dynamics software 5. Repeat steps 3 and 4 until the reactor system model completes the full-time calculation. Complete the multi-dimensional and high-fidelity coupling analysis of the reactor system.

The invention provides a coronary blood-flow volume acquiring method. The coronary blood-flow volume acquiring method comprises acquiring coronary image information to acquire coronary geometrical characteristic data; according to the coronary geometrical characteristic data, acquiring the total volume V of a coronary reference lumen, and calculating the blood-flow volume Q of an coronary openingaccording to a following formula, wherein, when the unit of Q is mm3 / s and that of V is mm3, K ranges between 5 and 9.5. The invention also provides a coronary blood-flow speed acquiring method. According to the coronary blood-flow volume and speed acquiring method, the coronary blood-flow volume and speed can be acquired through the coronary image information; compared with a method for estimating coronary blood-flow volume according to myocardium size in the prior art, the coronary blood-flow volume and speed acquiring method can provide more accurate boundary conditions for image-based hamodynamic calculation.

The invention discloses a method for determining object surface temperature under a fog-comprising condition. The method comprises the steps that: a fog-drop size distribution model and a fog-drop motion model are established; a heat transfer model of object surface under the fog-comprising condition is decomposed into a plurality of sub-models; a collision adsorption model of the fog-drops and the surface is established according to the fog-drop size distribution model and the motion model; an evaporation model of liquid film formed on the surface, a surface dew condensation model, a surface convection heat transfer model, a radiative heat transfer model between the surface and the atmosphere background, and a solar radiation model are established; object surface total heat flow is determined according to the object surface sub-models under the fog-comprising condition; and object surface temperature distribution is obtained according to an energy equation. According to the invention, the heat transfer model suitable for the object surface under a fog-comprising condition is established. Under a situation that external flow field is not calculated, the influences of external environments are converted into a plurality of reasonable and accurate boundary conditions. Therefore, object temperature field can be highly efficiently and rapidly calculated.

The invention discloses a calculation method for traction characteristics of straight-line running of a transport vehicle, relates to a calculation method for straight-line traction characteristics of vehicles, and belongs to the field of vehicle power calculation. The invention includes the following steps: Step 1: comprehensively consider various working conditions, and establish the relationship between the unit traction force and the straight-line speed of the engine under stable working conditions from the perspective of statistical probability of working conditions. Step 2: Use the relationship established in step 1 to establish the relationship between the unit traction force and the straight-line speed of the engine under steady working conditions, and calculate the traction force of the engine in each gear and the corresponding vehicle speed under different working conditions, and then evaluate the vehicle in a given working condition. The possibility of straight-line driving at a constant speed can be used to predict the steady-state performance of transport vehicles. The invention can be used for predicting the straight-line driving traction characteristics of mechanical or hydromechanical transmission piston engine wheeled or crawler vehicles.

The invention provides a refuse incinerator which comprises a fume spiral channel device, an incinerator body, a hot air gathering slot, a fume exhaust tube and a chimney, wherein the hot air gathering slot is arranged at the bottom of the incinerator body and is fixedly connected with the bottom surface of the incinerator body; the incinerator body comprises an insulating layer and an inner core layer; a space is reserved between the insulating layer and the inner core layer, thus forming a cold air preheating duct; the side wall at the top of the inner core layer is provided with an air hole; the side wall of the upper part of the incinerator body is provided with a feed port; fire bars are arranged on a bottom plate of the incinerator body; the fume spiral channel device is arranged at the top of the incinerator body; a fume spiral channel outer plate and the incinerator body define a fume spiral channel; the chimney is communicated with the fume spiral channel; and the fume exhaust tube is arranged on the side wall of a bottom end. The refuse incinerator has the advantages that the failure rate is low; the service life is long; the problem of influence of coking on fume flow path and oxygen supply in a hearth can be avoided; the refuse incinerating capacity is increased; and the incineration effect is good.

The invention discloses a method for determining tie line power feasible region based on multi-parameter programming theory, which mainly comprises the following steps: 1) acquiring power network basic parameters under AC tie line and power network basic parameters under DC tie line. 2) According to the basic parameters of power network under AC tie line, the optimal power flow model of external network under AC tie line is established. 3) According to the basic parameters of the power network under the DC tie line, the optimal power flow model of the external network under the DC tie line isestablished. 4) solving the feasible region of the power of the AC tie line; 5) solving that feasible region of the power of the DC tie line. The invention can accurately depict the feasible region ofthe power of the DC tie line and the AC tie line, provides accurate tie line boundary conditions for the optimization of the regional power network, and ensure the safety and economy of the optimization result of the regional power network.