81 results about "Kinetic theory" patented technology

This invention discloses a combined simulation method and a device for dynamic performance of trains and their circuit system, which utilizes a visual technology of computers to simulate various dynamic performances of stability, smoothness and curves of trains running on the circuit and simulates the operation state of any train at any circuit in carriages, trucks and various shaft locomotives and displays the moving state in three-dimension scene.

The invention discloses a simulation calculation method for an aerodynamic performance of an automobile wind protecting cover. The simulation calculation method for the aerodynamic performance of the automobile wind protecting cover comprises a first step of building a physical model of the fan wind protecting cover; a second step of carrying out calculation region setting and grid division; a third step of setting border conditions; a fourth step of carrying out simulation calculation on the aerodynamic performance of the wind protecting cover in the presence of a given rotating speed of the fan by utilizing CFD simulation software Fluent; and a fifth step of optimizing a wind protecting ring structure based on a vortex dynamic theory and characteristics of a flow field around vanes, and benchmarking with experimental data to verify accuracy of the model. By post-processing a simulation calculation result and utilizing the vortex dynamic theory and the characteristics of flow lines around the fan, the structure of the wind protecting cover is optimized, and the performance of the fan wind protecting cover is accordingly improved.

The invention provides a method for controlling coordinated operation of multiple missiles, which can accurately control the position, attack time, attack angle and attack velocity of each of the multiple missiles. The method comprises the following steps: selecting one missile from the multiple missiles to serve as a driving missile, and defining the rest missiles as driven missiles; assigning a virtual lead point to the driving missile as well as each of the driven missiles, and designing the path of motion of each lead point; determining the law of motion of the lead points in an arc coordinate system; establishing a model of relative motion of missiles and the lead points; designing the relative distances xr, yr and zr between the missles and the virtual lead points according to the needs of the missiles for cooperation in terms of position, attack angle and attack velocity; and designing a tracking controller based on the relative kinetics theory and allowing the missiles to fly in a way of tracking the virtual lead points with the designed relative distances, so as to perform coordinated operation. The method has the advantages of convenience in application and flexibility in use and has broad application prospects in the military field.

The invention relates to a road gradient and car state parameter combined estimation method based on a parameter estimation error, and belongs to the field of vehicle engineering. The method comprises the steps of firstly establishing a car driving longitudinal kinetic model according to a car kinetics theory and the newton second law; measuring a car speed and a driving force of an engine by virtue of a car-borne sensor, and adopting the measured car speed and the driving force as input quantities of an estimation algorithm; filtering the car driving longitudinal kinetic model, and extracting a parameter estimation error; judging whether an excitation condition is satisfied: estimating an unknown parameter vector by utilizing a vector designing self-adaptive law containing the parameter estimation error if the excitation condition is satisfied; adding random interference to the driving force if the excitation condition is not satisfied, and returning for re-measurement; finally calculating estimated values of a road gradient, car weight, viscous friction coefficient, rolling friction coefficient and air resistance coefficient by virtue of basic mathematical manipulation. By adopting the method, the cost is reduced, the accumulation of measurement noise can be avoided, and the precision is improved; the calculation quantity is reduced.

An UAV dynamic path planning method suitable for high-speed environment combines the theory of kinematic mechanics, establishes speed-dependent gravitational and repulsive functions, increases the virtual resistance, abandons the concept of "potential field", and directly calculates the resultant force born by the UAV through the virtual force function. The simulation experiments show that the method is effective and safe when the UAV is moving at high speed. The beneficial effect is that the method of the invention does not need to generate the motion path of the UAV, and only needs to calculate the expected resultant force of the UAV, not only reduces the complexity of the algorithm, but also substitutes the desired acceleration for the desired position as the input of the control system, so that one closed loop is omitted, the system complexity is lowered, the stabilizing time is greatly shortened, and the problem that the existing path planning method is not suitable for the high speed environment.

The invention provides a method for computational fluid dynamics and apparatuses making enable an efficient implementation and use of an enhanced jet-effect, either the Coanda-jet-effect, the hydrophobic jet-effect, or the waving-jet-effect, triggered by specifically shaped corpuses and tunnels. The method is based on the approaches of the kinetic theory of matter, thermodynamics, and continuum mechanics, providing generalized equations of fluid motion. The method is applicable for slow-flowing as well as fast-flowing real compressible-extendable fluids and enables optimal design of convergent-divergent nozzles, providing for the most efficient jet-thrust. The method can be applied to airfoil shape optimization for bodies flying separately and in a multi-stage cascaded sequence. The method enables apparatuses for electricity harvesting from the fluid heat-energy, providing a positive net-efficiency. The method enables efficient water-harvesting from air. The method enables generators for practical-expedient power harvesting using constructive interference of waves due to the waving jet-effect.

The invention relates to five-shaft structure error measuring method of a mirror image milling system, a system and a device thereof. The method comprises the steps of constructing a geometric model,based on a multi-body system kinetic theory, constructing a geometric model of spatial positioning errors of a cutter central point P0 of a mill image milling processing area and a supporting centralpoint P1 of a supporting head in a motion process; acquiring pose data, through a displacement measuring device on a processing head of the mirror image milling system, acquiring pose (position and attitude) data of P0 and P1 in a preset measuring path; calculating a dynamic error, performing calculation processing on the acquired pose data of the P0 and P1, and obtaining a characteristic value ofthe motion error of the five-shaft structure; and performing data feedback adjustment, and based on the characteristic value of the five-shaft structure, performing feedback of the error compensationdata of the five-shaft structure to the control system of the image mirror milling system, making adjustment of the five-shaft structure according to error compensation data by the control system, sothat the supporting head performs synchronous movement with the processing head.

The invention relates to the field of metallurgy, in particular to a single pipe style multifunctional vacuum refining system and a method thereof. Aiming at the problems that when DH, VD, RH and single snorkel refining furnaces are used for steelmaking, the refining efficiency is low and a whole furnace steel scrapping risk exists in a smelting process, the invention provides the single pipe style multifunctional vacuum refining system and the method thereof based on metallurgical kinetics theoretical calculation. An argon blowing device is arranged around a single dip pipe, and argon blowing bubble size and amount and argon blowing time are adjusted and controlled, so the refining efficiency is improved, the service life of the dip pipe is prolonged, and the potential scrapping risk of ladle water caused by the fault or low efficiency of the argon blowing device when argon is blown at the bottom or only at one side is eliminated.

The invention discloses a method for predicting a pyrolysis process of environment-friendly flame-retarding asphalt, belongs to the technical field of flame retarding of asphalt pavements, and solves the problems of low prediction accuracy in the pyrolysis process of an asphalt material and lack of scientific theoretical basis in the prior art. By virtue of the method, the pyrolysis behavior of the environment-friendly flame-retarding asphalt in a high-temperature environment can be deeply revealed. The method comprises the following steps: adding an environment-friendly flame retardant magnesium hydroxide in hot asphalt according to a certain proportion; fully stirring to prepare a uniform and stable flame-retarding asphalt sample; performing test through a thermogravimetric analyzer to acquire data such as a thermogravimetry-derivative thermogravimetry (TG-DTG) curve and char yield; performing optimization and identification through a reaction mechanism according to a thermal analysis kinetic theory, determining a flame-retarding asphalt pyrolysis reaction mechanism function and a conversion rate function to work out pyrolysis kinetic parameters of a flame-retarding asphalt material, namely activation energy and pre-exponential factors; establishing a flame-retarding asphalt pyrolysis model with certain flame retardant mixing amount to obtain a flame-retarding asphalt pyrolysis TG curve through the model so as to predict an asphalt pyrolysis process.

The invention provides a method for designing a passive vibration isolation system for a flywheel of a satellite. The method includes analyzing configuration and composition of the flywheel, creating and correcting a multi-body kinetic model of the flywheel on the basis of a multi-body kinetic theory and a finite element theory; providing a design of a passive vibration isolation scheme for the flywheel according to ground test data and a simulation analysis result for vibration characteristics of the corrected model of the flywheel; performing simulation analysis on the performance of the scheme according to a combination of the design of the scheme and the kinetic model of the flywheel, verifying the scheme by means of ground tests if index requirements are met, or redesigning the scheme if the index requirements are not met; performing ground passive vibration isolation tests on the flywheel in order to further verify the feasibility of the scheme, completing a design procedure if requirements are met, or redesigning the passive vibration isolation scheme if the requirements are not met. The passive vibration isolation scheme includes a vibration isolator rigidity design, a damping design and a layout design. The method has the advantages that micro-vibration interference of the flywheel on a satellite platform can be effectively reduced, and technical support can be provided for development of high-precision, high-resolution and high-stability hyper-static platforms.

The invention belongs to the field of road traffic safety. In order to provide a method for traffic safety evaluation during phase switching and achieve the purpose, the invention adopts the technical scheme that the method for evaluating traffic safety of signal intersection during phase switching facing an operation management stage comprises the following steps of: calculating encountering time difference PET, wherein PET=(Y+AR+te)-tc-Te; calculating collision loss of momentum, assuming that two cars collide with each other by keeping the original speed, according to the collision kinetic theory, calculating the loss of momentum before and after collision according to formula 5, wherein the system collision before momentum Pm; calculating the collision occurrence probability P; and carrying out evaluation on the traffic safety of the intersection during phase switching. The method is mainly applied to the design of roads meeting the requirement of traffic safety.

The invention discloses a wind turbine generator system self-adaptive inversion sliding mode optimized control method based on a high-order sliding mode observer. The method includes the steps that a,a mathematical model of a wind turbine generator system is established according to kinematics and dynamics theories; b, a self-adaptive inversion sliding mode controller of the wind turbine generator system is designed on the basis of the traditional optimal torque method design through inversion control, self-adaptive control, sliding mode control theories and the mathematical model; c, the system state is estimated online in real time through the high-order sliding mode observer, the power output is smoothened, and shake and vibration are reduced; d, parameter optimization is conducted onthe designed controller through a particle swarm algorithm to find the optimal control parameter; and e, self-adaptive inversion sliding mode control is conducted on the wind turbine generator systemthrough the self-adaptive inversion sliding mode controller with the control law. In this way, the problems that the wind turbine generator system has unknown parameters and bonded disturbance are solved, and robustness of the system is improved. Finally, the maximum power point tracing control of the wind turbine generator system in the low-wind-speed area is achieved.

The invention relates to non-optical spherical elements, in particular to a splicing measurement method for two sections of profiles of a large-caliber optical aspheric element. The splicing measurement method includes providing a method of aligning data points of an overlapped area on the basis of a principle that radius of curvature is unchanged; building a preliminary optimized mathematic model for twp-section surface figure profile splicing according to a multibody system kinetic theory, a slope difference value and an inversion method; according to a simulation result of the preliminary splicing mathematic model, performing linear least square fitting on preliminary splicing errors, removing accumulated errors, and providing a final two-section splicing optimized algorithm. Experiments in which a Taylor Hobson contourgraph and an auxiliary measuring clamp are utilized to measure planar optical elements of 150mm and data processing by using the splicing optimized algorithm are performed, and results of the experiments show that maximum standard deviation of the splicing errors is 0.868 micrometer, and high-accuracy surface figure detection needs of optical elements at a grinding stage can be met.

The invention discloses automobile rollover evaluation indexes and evaluation method, and belongs to the field of vehicle active safety. In the method, the theory of vehicle rollover dynamics is applied to solve rollover threshold conditions of the automobile rollover evaluation indexes, and the rollover threshold conditions are converted into a phase diagram mode; and a roll angle, a roll angle acceleration and a lateral acceleration which are measured in real time during a driving process of the automobile are converted into a phase diagram of the roll angle and the roll angle acceleration,a phase diagram of the roll angle and the lateral acceleration and a phase diagram of the lateral acceleration and the roll angle acceleration, and the phase diagrams are compared with the rollover threshold conditions to judge whether the automobile is at risk of rollover. Driving parameters measured in real time are directly compared with the threshold conditions, and so the rollover evaluationindexes are accurate and the real-time performance is good. Furthermore, The imaging of the parameters can more directly reflect the influence of a plurality of parameters on the automobile rollover,which is conducive to guiding drivers or active safety equipment to take anti-rollover measures in actual driving.

The invention discloses a personalized drill bit dynamic design method for a complex and difficult-to-drill stratum. The personalized drill bit dynamic design method comprises the following steps thatS1, rock drillability indexes of the drilled stratum are obtained; s2, performing drill bit tooth rock breaking digital simulation analysis and a gear ring and drill bit composite rock breaking experiment, and establishing a shaft bottom rock interaction mechanical model; s3, establishing a drill string Drill bit The rock system is coupled with the overall dynamic model; s4, designing the toothshape, the tooth distribution density, the crown shape and the gauge protection structure according to the rock mechanical property of the complex difficult-to-drill stratum; s5, optimizing the parameters of the nozzle and the hydraulic structure of the drill bit by utilizing a computational fluid dynamics theory and a numerical simulation method; s6, a tooth material cobalt removal strengtheningtechnology, a high-strength drill bit body material technology and a special tooth-shaped tooth technology are adopted, and the manufacturing process of the drill bit is optimized; the personalized drill bit design method has the advantages that the personalized drill bit design method for the complex and difficult-to-drill stratum is provided, so that the drill bit development period is shortened, and the development cost is reduced.

A method for determining optimum catalyst particle size for a gas-solid, liquid-solid, or gas-liquid-solid fluidized bed reactor such as a slurry bubble column reactor (SBCR) for converting synthesis gas into liquid fuels considers the complete granular temperature balance based on the kinetic theory of granular flow, the effect of a volumetric mass transfer coefficient between the liquid and the gas, and the water gas shift reaction. The granular temperature of the catalyst particles representing the kinetic energy of the catalyst particles is measured and the volumetric mass transfer coefficient between the gas and liquid phases is calculated using the granular temperature. Catalyst particle size is varied from 20 μm to 120 μm and a maximum mass transfer coefficient corresponding to optimum liquid hydrocarbon fuel production is determined. Optimum catalyst particle size for maximum methanol production in a SBCR was determined to be in the range of 60-70 μm.

The invention belongs to the technical field of aeronautical engineering and particularly relates to a dynamics simulation model of an aircraft arrestment landing process. The method is characterized in that a many-body dynamics theory is combined, a complete aircraft arrestment landing dynamics mathematic model is established, and arrestment landing use conditions of various typical landing attitudes are comprehensively considered, so that a complete aircraft arrestment landing dynamic characteristic analysis method of the system is established. The method has the beneficial effects that by virtue of dynamics simulation calculation, the aircraft landing tailhook load and the load impacting an aircraft body are obtained, reference is provided for the aircraft arrestment characteristic analysis, and meanwhile a basis is provided for designing a tailhook; the modeling time can be saved, the manufacture and test expenses of a test piece are reduced, the working efficiency is improved, and the method has important engineering application value.

The invention provides a method for computational fluid dynamics and apparatuses making enable an efficient implementation and use of an enhanced jet-effect, either the Coanda-jet-effect, the hydrophobic jet-effect, or the waving-jet-effect, triggered by specifically shaped corpuses and tunnels. The method is based on the approaches of the kinetic theory of matter providing generalized equations of fluid motion and is generalized and translated into terms of electromagnetism. The method is applicable for slow-flowing as well as fast-flowing real compressible-extendable generalized fluids and enables optimal design of convergent-divergent nozzles, providing for the most efficient jet-thrust. The method can be applied to airfoil shape optimization for bodies flying separately and in a multi-stage cascaded sequence. The method enables apparatuses for electricity harvesting from the fluid heat-energy, providing a positive net-efficiency. The method enables generators for practical-expedient power harvesting using constructive interference of waves due to the waving jet-effect.

The invention discloses a method for separating and extracting shell pieces and clitellum from kieselguhr or diatoms. The method comprises the following steps of: classifying and extracting the shell pieces and the clitellum by adopting a Stokes sedimentation method in the extraction process; calculating the sedimentation velocity difference between the shell pieces and the clitellum with same particle diameters by combining with a fluid dynamics theory; and carrying out sedimentation by adding deionized water a plurality of times to finish high-purity classification and extraction of the shell pieces and the clitellum. The method can not damage structures of the shell pieces and the clitellum and keep the topography and the microstructure of the original species of diatoms, and the shell pieces and the clitellum are only separated at connecting strips. 0.2 to 0.6g of shell pieces and 0.1 to 0.3g of clitellum can be extracted from 1g of siliceous shells.

The invention discloses a multi-scale simulation method for multiphase electrohydrodynamics of core-shell structure. According to the method, three-phase fluids are considered and include core and shell printing fluids and surrounding wrapping air; tensions at different fluid interfaces are calculated by adopting a micro-scale all-atomic molecular dynamics method; a viscosity pressure tensor is calculated by adopting a meso-scale lattice Boltzmann method; information obtained by micro-scale and meso-scale calculation is substituted into a macro-scale; a multi-scale calculation model is built;and an injection characteristic is obtained. The multi-scale calculation model can improve the calculation efficiency, save the calculation resources and take the calculation precision into account, and has important theoretical significance for perfecting a multiphase electrohydrodynamics theory of the core-shell structure.

The invention relates to the technical field of freshness preservation, in particular to a fruit and vegetable respiration rate model. A fruit and vegetable respiration rate modeling method comprises the following steps of: firstly, establishing a model that a respiration rate changes along with storage time: r=K1{1-K2exp(-kdt)}, in the formula, K1=ks/kd*k and K2=1-kd/ks[E]0; secondly, on the basis of the established model that the respiration rate changes along with storage time, establishing a respiration rate model which contains a storage temperature and a storage time factor: r=K3{1-K2exp(-kdt)}, in the formula, K3=ks/kd*Aexp(-Ea/RT); and finally, on the basis of the established respiration rate model which contains the storage temperature and the storage time factor, establishing the respiration rate model which contains a gas volume fraction and the storage time factor: r=K4{1-K2exp(-kdt)}, in the formula, K4=ksktheta/kd*ayO/(1+ayO+aiyOyC). Due to the adoption of the technical scheme, a mathematical model about the respiration rate of fruit and vegetable main bodies is established based on an enzyme kinetic theory to lay a theoretical foundation for the predication of the respiration rate of the fruit and vegetable main bodies in an air conditioned storage period and the analysis of storage quality.