139 results about "Momentum conservation" patented technology

The invention discloses a vivid and interesting desktop icon displaying method and device. The method includes the following steps: when entering a desktop, initializing desktop icons, and randomly distributing same or different initial directions and initial speeds to all the desktop icons of the current desktop; detecting whether collision occurs among the icons or not in real time; if yes, playing a pre-stored first collision sound, and calculating respective motion directions and motion speeds of two collided icons according to the momentum conservation law and the energy conservation law; detecting whether the icons collide with the edge of a touch screen or not in real time; if yes, playing a pre-stored second collision sound, wherein the icons rebound in a collision speed. After the vivid and interesting desktop icon displaying method and device is applied, the terminal desktop displays showy dynamic effect and makes the icon collision sounds, and users can interact with the desktop and optionally change motion state of the icons, so that much interestingness is realized, and the users have a lot of fun and good use and operation experiences.

A general purpose program implemented on a computer analyzes steady state and transient flow in a complex fluid network, modeling phase changes, compressibility, mixture thermodynamics and external body forces such as gravity and centrifugal force. A preprocessor provides for the interactive development of a fluid network simulation having nodes and branches. Mass, energy, and specie conservation equations are solved at the nodes, and momentum conservation equations are solved in the branches. Contained herein are subroutines for computing "real fluid" thermodynamic and thermophysical properties for 12 fluids, and a number of different source options are provided for modeling momentum sources or sinks in the branches. The system of equations describing the fluid network is solved by a hybrid numerical method that is a combination of the Newton-Raphson and successive substitution methods. Application and verification of this invention are provided through an example problem, which demonstrates that the predictions of the present invention compare most reasonably with test data.

A method and apparatus for analyzing steady state and transient flow in a complex fluid network, modeling phase changes, compressibility, mixture thermodynamics, external body forces such as gravity and centrifugal force and conjugate heat transfer. In some embodiments, a graphical user interface provides for the interactive development of a fluid network simulation having nodes and branches. In some embodiments, mass, energy, and specific conservation equations are solved at the nodes, and momentum conservation equations are solved in the branches. In some embodiments, contained herein are data objects for computing thermodynamic and thermophysical properties for fluids. In some embodiments, the systems of equations describing the fluid network are solved by a hybrid numerical method that is a combination of the Newton-Raphson and successive substitution methods.

The invention belongs to the technical field of aero-engines, and particularly relates to an aero-engine nonlinear model modeling method. The method comprises the following steps: calculating an engine design point nonlinear model, and calculating a transmitter transition state nonlinear model; the method comprises the steps that an engine subsection model is established, and the model is mainly divided into an air inlet channel, a fan, a gas compressor, a combustion chamber, a turbine and an exhaust port according to the structure and function of an aero-engine; describing the aerothermodynamic law obeyed by each component during working by using a nonlinear equation in sequence, and establishing a component-level model of an aeroengine design point; the latter assumes that the characteristics of the parts in the transition state are the same as those in the steady state, and the volume effect of the parts is considered in numerical simulation in the transition state; only the volumetric effect of parts with large volumes is considered in calculation, and meanwhile momentum conservation is simplified to be replaced by the total pressure recovery coefficient of the channel, so thatenough engineering precision can be ensured, and calculation is greatly simplified.

The invention discloses a collaborative path planning method for a kinematic redundant two-arm space robot. The collaborative path planning method for the kinematic redundant two-arm space robot comprises the following steps that a dynamic equation and a kinematic equation of a space robot system are established; a redundant solution of an inverse kinematics equation of an end-effector is solved,and a system non-holonomic constraint equation is obtained through a momentum conservation equation; a task space constraint equation of the relationship between the end-effector motion and the attitude of a base is obtained through the system non-holonomic constraint equation; the path planning of the end-effector in a task space is obtained by using a quintic bezier curve, and path execution time is determined by the velocity and acceleration boundary of the end-effector; and the joint motion trajectory planning corresponding to different task priorities is obtained through the end-effectormotion equation and the task space constraint equation. The collaborative path planning method of the space two-arm robot is implemented, various tasks can be performed according to the priorities ofthe tasks such as a multi-arm collaborative task and a dynamic balancing task, and the operation ability of a space manipulator is greatly expanded.

The invention provides a coupling analysis method for a one-dimensional mathematical model and two-dimensional mathematical model of river way outburst flood. After corresponding data is collected, adyke breach outflux inundated area and a river way section obviously influenced by dyke breach outflux are first dispersed by using a quadrilateral or triangular unstructured grid, and other river sections adopt one-dimensional cross-section data generalization. The one-dimensional model is solved by adopting a classical Presimann implicit format, the two-dimensional model is solved by adopting aGodunov format with a shock capturing ability. In order to avoid numerical oscillation, mass conservation and momentum conservation of the connection portion between the one-dimensional mathematical model and the two-dimensional mathematical model are ensured; according to the coupling analysis method for the one-dimensional mathematical model and two-dimensional mathematical model of river way outburst flood, provided connection portion is a transition region, one-dimensional model calculation and two-dimensional model calculation are both conducted in the transition region. After the dyke breach is started, the dyke breach outflux inundated area and a river way two-dimensional computing area automatically become an integrated two-dimensional computing area, and the calculation of dyke breach outflux process is completed by the two-dimensional model. The processing method can fully consider the hydrodynamic response process inside and outside the river way on the dyke breach, the numerical simulation precision of the dyke breach outflux process is improved, and the shortcoming in a traditional method is overcome that only a weir formula is adopted to calculate the dyke breach outflux process, so that the momentum exchange inside and outside the river way can not be considered.

The invention discloses an automatic balancing device and method of a motorcycle-type robot. The automatic balancing device is applied to the motorcycle-type robot, the motorcycle-type robot and the automatic balancing device form a single-dimensional inverted pendulum structure supported by two points, upright automatic balance of the motorcycle-type robot is achieved through the adoption of themomentum exchange principle in the inverted pendulum principles and according to the momentum conservation law; the automatic balancing device comprises a gesture collector for detecting gesture dataof a motorcycle body tilting leftwards and rightwards, a momentum wheel, a motor driving the momentum wheel to rotate and a motorcycle body controller connected with the gesture collector and the motor separately, the motorcycle body controller obtains the rotation data of the momentum wheel and the gesture data and utilizes a control algorithm to control the motor to output motor rotation data corresponding to the gesture data and the rotation data, and therefore the momentum wheel is controlled to rotate to achieve the upright automatic balance of the motorcycle-type robot.

The invention discloses a resistance distribution-based method for analyzing a sub-channel with a grid mixing effect. The method comprises the steps of collecting experimental data of multiple mixing grids including a mixing grid of a to-be-analyzed reactor core in different working conditions, fitting a momentum source term relational expression capable of reflecting mixing performance of key parts of the mixing grids, and adding the momentum source term relational expression to a corresponding momentum conservation equation; and by solving a mass conservation equation, the momentum conservation equation and an energy conservation equation, obtaining more accurate local thermo-hydraulic parameters in the reactor core, thereby enabling prediction of a critical heat flux (CHF) value and a CHF position to be more accurate. The method is not limited by a structure and a solving method of a sub-channel program, and can be widely applied to the calculation of various types of sub-channel programs including a sub-channel program of a uniform flow model, a drift flow model or a two-fluid model.

A photoetching machine workpiece stage magnetic preloading balance positioning system belongs to the field of semiconductor photoetching technology; the system mainly comprises a base stage, a balance mass system, a magnetic preloading system, a motion unit, a silicon wafer stage, and a balance mass drift-resistant system; the balance mass system comprises two frames which nest each other, and has freedom degrees in the X and Y directions; the motion unit is disposed at the upper part; the impact force caused by the motion part to the base stage is weakened by momentum conservation principle;the balance mass drift-resistant system is used to compensate the position displacement of the balance mass system caused by external resistance during working; the magnetic preloading system is usedfor real-time compensation of the torsion of the workpiece stage along a Z axis; the invention can effectively reduce internal vibration, compensate the torsion of the workpiece stage along the Z axis, and thus greatly improve the motion positioning precision of the silicon wafer stage.

The invention discloses a method using a mechanical arm to inhibit the attitude interference of a spacecraft pedestal. The method comprises the following steps that a many-body dynamic model is established according to configuration of a space robot, and a momentum conservation problem of the mechanical arm, an antenna and the pedestal is analyzed on the basis of the model; a track of the spatialmechanical arm is designed by considering the task priority on the basis of a dynamic balance control and zero-reaction space theory, so as to coordinate a tail-end executor task of the spatial mechanical arm and inhibit an attitude interference task of the satellite pedestal; and on the basis of the analysis, closed-loop inverse kinetic control of the spatial mechanical arm is designed, and the problem that error accumulation is increased gradually in pedestal attitude inhibition is solved. Concepts of dynamic balance control and zero reaction space are combined, and the track of the kineticredundancy mechanical arm is constructed to inhibit aircraft pedestal attitude interference caused by other rotation mechanisms.

The invention relates to a method for testing actuating pressure of an explosion contact surface of an explosive and a test device. According to the method, the purpose of test on the explosion pressure of the explosive under high temperature and high pressure (dozens of GPa) is achieved. The pressure on the explosion contact surface comprises change of pressure on the contact surface, which is caused by the pressure in an explosive detonation strengthening and attenuating process. Theoretical derivation for measuring the explosion pressure is realized by a higher mathematics calculus relation and value analysis method according to momentum conservation in order to realize measurement of the pressure on the explosion contact surface of the explosive. The test device is designed to comprise an explosion container, a throwing columnar rigid body, a high-speed camera, a data analysis system, a vacuum pump, a safety valve, a container for the throwing columnar rigid body, a detonation device and a scaleplate.

Methods for computer-implemented simulation for the interaction of two or more objects are provided. Data describing particles that represent each of the objects is generated from geometric data for objects. The data for each particle describes a mass density, velocity and energy at a position of the corresponding object. The particles are grouped into sectors to define a computational mesh comprising a plurality of sectors, wherein each sector is a volume region at a position in space in which particles associated with the objects may reside. For each of a plurality of select particles, so called neighboring particles are determined that are within a region of influence with respect to a select particle. Computations are performed based on laws of conservation of mass, energy and momentum to produce updated values for mass, velocity, energy, pressure, stress and position for the particles at each of a plurality of time steps. According to one aspect, when determining neighboring particles for a given select particle, a search is made through a limited or bounded volume region with respect to the select particle that consists of the region of influence for the select particle at the previous time step and within those sectors in contact with or bordering the region of influence at the previous time step. According to another aspect, the plurality of select particles are identified as those particles that reside in an active sector, wherein an active sector is a sector that contains, or is adjacent to a sector that contains, particles that is actively involved in the engagement between the two objects. For example, an active sector is a sector that contains, or is adjacent to a sector that contains, at least one particle that has a velocity, pressure or stress greater than a corresponding predetermined amount.

The invention provides a modeling method for a coupling numerical value of cracking reaction in a furnace tube and combustion of an industrial dichloroethane cracking furnace chamber. According to the method, the dichloroethane cracking furnace is divided into a furnace chamber model and a furnace tube model during modeling, and grids are divided on the furnace chamber and the furnace tube. The furnace chamber takes an outer tube wall temperature given by the furnace tube model as a boundary condition, important furnace chamber parameter distribution of the furnace chamber flue gas temperature, the speed, the component concentration and the like is calculated by a combustion model, a flowing model and a heat transmission model; the furnace tube takes a furnace tube heat flux calculated by the furnace chamber as a boundary condition, and process temperature, pressure and concentration distribution in a tube length direction is calculated through a cracking reaction model in the tube and taking mass conservation, momentum conservation, energy conservation relations in the tube, so that analyses of important economic targets of the dichloroethane cracking conversion rate, the selectivity, the unit consumption and the like under current operation conditions are facilitated, and guidance of filed process optimization is facilitated. The modeling method is applicable to various high-temperature cracking furnaces and has a wide adaptability.

The invention relates to a method for measuring the concentration distribution of compositions in a particle-fluid two-phase flow reactor. The method comprises the following steps of: S1, calculation of the mass conservation equation and the momentum conservation equation of each micro unit in a measuring area of the particle-fluid two-phase flow reactor and acquisition of the fluid-solid speed and the particle concentration distribution of each micro unit; S2, acquisition of matrixes which are formed by spacial discrete distribution of dilute and dense phase structural parameters; S3, acquisition of the composition concentration of dilute phase and dense phase; S4, calculation of the mean fluid density of the micro unit according to the composition concentration of the dilute phase and the dense phase, in which, if the mean fluid density meets the precision requirement, the fluid-solid speed, the particle concentration and the composition concentration are outputted and the operation is ended; if the mean fluid density fails to meet the precision requirement, the calculated mean fluid density of the dilute phase and the dense phase is substituted in the step S1, and the next iteration begins. The method introduces a multi-scale flow structure into the particle-fluid mass transfer measuring process, takes malconformation of local mass transfer into account, and more accurately measures the composition concentration distribution in the particle-fluid two-phase flow reactor.

The invention discloses a general hydrodynamic calculation method for an ultra-supercritical boiler, and provides a flow network system method consisting of a nonlinear model applied to a computer. The calculation method is suitable for hydrodynamic calculation and wall temperature safety analysis of the ultra-supercritical once-through boiler under various boiler overall arrangement forms, various pipe coil forms, various combustion technologies and various mass velocity combinations. The method comprises the steps of simplifying a water wall into a flow network system consisting of elements such as a connecting pipe loop, a heated loop, a pressure node and the like according to structure characteristics of the water wall and heat load distribution of a furnace chamber; and building the nonlinear calculation model of flow distribution according to a mass conservation equation, a momentum conservation equation and an energy conservation equation. Through direct solving of a nonlinear equation set, flow distribution and node pressure distribution in the heated loop and a connecting pipe are determined, and based on this, boiler water wall flow and metal wall temperature are subjected to safety check, so that guidance calculation can be performed for design and safety check of the boiler.

A device with models constructed based on thermodynamics laws and fluid dynamics laws including the energy conservation law, momentum conservation law and mass conservation law. Compressor outflow flow rate calculation section calculates the flow rate of air that flows out of a compressor based on a relationship between an in-cylinder intake air flow rate during steady-state operation in an internal combustion engine system and supercharging pressure, which is pressure of air compressed by the compressor, and a value of the in-cylinder intake air flow rate calculated by in-cylinder intake air flow rate calculation section.

The invention relates to a method for inverting the mass concentration of atmospheric particulates based on the flight time of the particulates. The mass concentration of the particulates can be inverted according to the flight speed and the sampling flow on the basis of an aerodynamic particulate spectrometer. According to the work principle of the aerodynamic particulate spectrometer, the particulates with different particle sizes have only speed up at any one point on an airflow track after the particulates pass through an accelerating nozzle, so the flight speed of particles can be obtained through the flight time. The relationship between the flight speed and the mass of the particles can be obtained according to a momentum conservation theorem and aerodynamic and hydromechanical principles, so the mass concentration of the particulates can be inverted through the flight speed and the sampling flow. The method provided by the invention can be used for inverting the mass concentration of the atmospheric particulates according to the dynamic feature of the particulates and provides an inversion algorithm capable of measuring the mass concentration of the atmospheric particulates accurately, in real time and on line.

The invention relates to an optimal transportation meshless (OTM) method for solving large deformation of a material and aims at solving the problems of effective and stable solving of maximum deformation, high-speed impact and geometric distortion, metal material molding, multiphase coupling and the like. The OTM method adopts a material point and node pair original problem domain to perform discretion and adopts a local maximum entropy interpolation function to construct a continuous movement function, and the problem that mesh distortion caused in maximum deformation processed by adopting a finite element method, the problem that a Dirichlet boundary condition cannot be directly added for a meshless method, calculating misconvergence and the like are avoided. In addition, due to the fact that interpolation and integration are performed at different discrete points, an effective meshless numerical integration mode is provided, and the problem of tensile stress instability is solved. The OTM method serves as an incremental updating Lagrangian method to make mass conservation automatically achieved without solving. Time discretion is performed by adopting an optimal transportation theory, the momentum conservation and symplectic conservation of a discrete system are ensured, and the operation efficiency and precision are greatly improved.

The invention provides a method for casting grain structure numerical prediction, and relates to a prediction method of a casting grain structure. The method aims at solving the problems that in existing grain structure numerical prediction, the calculation time is long and the calculation amount is large. The method includes the steps of calculating a dendritic crystal growth kinetics KGT model first, obtaining the dendritic crystal tip radius-dendritic crystal tip growth speed change curve, conducting macro-scale mesh generation on a casting system, only calculating an energy conservation equation for a computational grid (i,j)chan=/0 to obtain temperature field distribution, calculating a momentum conservation equation for a computational grid (i,j)chan=0 to obtain the metal liquid flowing speed in the computational grid, judging whether the computational grid (i,j)chan=0 is located on the solidification front or not, calculating the solidification front temperature gradient and the solidification front movement speed corresponding to the grid if yes, and outputting distribution of a grain growth morphology identification grain in a casting till solidification ends. The method is suitable for casting grain structure numerical prediction.

The invention discloses a magnetic levitation guide rail used for verifying momentum conservation law in high school physics, belonging to the technical field of high school physics experiment equipment. The magnetic levitation guide rail includes a base, the upper end of the base is fixedly connected with a fixed guide rail, the fixed guide rail is sleeved with a pair of sliding blocks matched with the fixed guide rail, the two sliders have the same mass, There is a gap between the stationary guide and the slider, the lower end of the fixed guide rail is fixedly connected with a pair of firstsuspension magnets, the slider is fixedly connected with a second suspension magnet matched with the first suspension magnet, the principle of magnetic levitation can be realized, The invention replaces the air cushion guide rail of the external air pump in the high school experiment, is simple in operation and convenient in handling, solves various complicated assembly steps of the air pump usedin the prior art to a great extent, eliminates various potential safety hazards, greatly improves the teaching efficiency of teachers, and facilitates students to learn knowledge through the experiment quickly and accurately.

The present invention is method and device for measuring impact kinetic energy of resiliometer and belongs to the field of resiliometer metering and calibrating technology. Through measuring the hammer impulse the attack rod transmits during attacking and calculating the striking speed of the hammer to the attack rod by means of the impulse-momentum conservation law, the impact kinetic energy of the resiliometer is obtained and used in metering and calibrating the resiliometer. The present invention may be used in different types of resiliometer, and has low measuring cost and fast and convenient resiliometer metering and calibrating.

The invention discloses a component nonuniformity numerical prediction method for magnesium alloy casting parts, and relates to a component nonuniformity numerical prediction method for magnesium alloy casting parts. The objective of the invention is to solve the problem that macrosegregation formation of the magnesium alloy casting parts cannot be accurately predicted by an existing method. The component nonuniformity numerical prediction method comprises the following steps: 1, simulating the growth of alpha-Mg dendrites with different growth orientations by adopting a cellular automaton method to obtain a curve that the specific surface area of the dendrites changes along with the solid phase fraction; 2, performing mesh generation on the casting system; 3, calculating an energy, component and momentum conservation equation for all grids with subscript char = 0, and obtaining distribution of temperature, average component and speed in the casting parts; 4, calculating an energy conservation equation for all grids of which the subscript chars are not 0 to obtain temperature distribution; and 5, repeating the step 2, the step 3 and the step 4 until solidification is finished, and outputting an average component field in the casting parts. The component nonuniformity numerical prediction method is applied to the field of magnesium alloy casting part component prediction.