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Journal of System Simulation

Numerical simulation

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Full-Text Articles in Engineering

An Intelligent Driver Model Simulation Considering Both Backward Looking Effect And Velocity Difference, Yin Xu, Yun Pu, Haixu Liu, Yifan Tan Aug 2023

An Intelligent Driver Model Simulation Considering Both Backward Looking Effect And Velocity Difference, Yin Xu, Yun Pu, Haixu Liu, Yifan Tan

Journal of System Simulation

Abstract: Aiming at the phenomenon that driver adjusts vehicle movement by observing the following vehicles through rearview mirror in the actual car-following driving, an improved intelligent driver model accounting for both backward looking effect and velocity difference is proposed, and the critical stability condition of the new model is obtained by employing the linear stability analysis. Based on the numerical simulation experiments, the car following characteristics analysis during the acceleration process of the vehicle and the traffic safety evaluation are carried out. A small disturbance simulation under the periodic boundary condition is used to verify the conclusion consistency of stability …


Numerical Simulation Of Aerodynamic Characteristics For Double-All-Wing Unmanned Aerial Vehicle Based On Computational Fluid Dynamics Theory, Kuizhi Yue, Zhang Yuan, Liangliang Cheng, Dazhao Yu Jul 2021

Numerical Simulation Of Aerodynamic Characteristics For Double-All-Wing Unmanned Aerial Vehicle Based On Computational Fluid Dynamics Theory, Kuizhi Yue, Zhang Yuan, Liangliang Cheng, Dazhao Yu

Journal of System Simulation

Abstract: Follow the rapid progress of the nation's blue ocean strategic projection capability of sea power, an Unmanned Aerial Vehicle (UAV) with double-all-wing configuration is studied to match the trend. The UAV is conceptually designed by CATIA software, the aerodynamic characteristic of the model is numerically simulated by computational fluid dynamics (Computational Fluid Dynamics, CFD) theory, and the performance of the UAV to take off from the aircraft carrier is also analyzed. The lift coefficient, drag coefficient and lift-drag ratio of the double-all-wing UAV model with a angle of attack of 0 can reach 0.596 2, 0.037 6 and 15.824 …


Study On Navigation Simulation Method Of Crude Oil Fleet In Bridge Area, Chunhui Zhou, Hongxun Huang, Wanxia Yi, Lijia Chen, Yuanqiao Wen, Linxu Tan Mar 2021

Study On Navigation Simulation Method Of Crude Oil Fleet In Bridge Area, Chunhui Zhou, Hongxun Huang, Wanxia Yi, Lijia Chen, Yuanqiao Wen, Linxu Tan

Journal of System Simulation

Abstract: In view of the safety of over-scale fleet sailing through bridge, the water area of Wuhan Yangtze River Bridge is taken as the research area. Numerical simulation of flow field is conducted based on MIKE software to analyze the changes of water flow in different water periods and their effects on ship navigation. On this basis, according to the simulation results of the flow field, several test conditions are set up by using the Large Ship Maneuvering Simulator to carry out the simulation test of over-scale fleet sailing through the bridge. The results show that under the preset wind …


Error Correction Methods In Numerical Simulation For Unilateral Constraint Dynamics, Haitao Gao, Yali Han, Youxiong Xu, Songqing Zhu, Zailuo Wu Sep 2020

Error Correction Methods In Numerical Simulation For Unilateral Constraint Dynamics, Haitao Gao, Yali Han, Youxiong Xu, Songqing Zhu, Zailuo Wu

Journal of System Simulation

Abstract: Aiming at problem of calculation errors and constraint violation in numerical simulation for dynamics of unilateral constraint such as contact and collision, the error projection correction methods were put forward. On the basis of dynamical behavior of unilateral constraint described by linear programming model, mixed linear complementarity dynamics was built. Numerical simulation methods for the mixed linear complementarity dynamics were derived. In order to reduce calculation error and constraint violation caused by this error in the numerical simulation, an error correction method was built for correcting position and velocity error of numerical solution on the base of bilateral …


Simulation Study On External Explode Of Large Equivalent Charge On Large Buildings, Weiping Zhao, Xiankun Ge, Chuanwu Liu, Fengchun Zhu Aug 2020

Simulation Study On External Explode Of Large Equivalent Charge On Large Buildings, Weiping Zhao, Xiankun Ge, Chuanwu Liu, Fengchun Zhu

Journal of System Simulation

Abstract: The particle algorithm in AUTODYN, Smoothed Particle Hydrodynamics (SPH), was used to simulate dynamic damage of the external explosion on large buildings, which provided a visual effect. The dynamic damage details of reinforced concrete and brick masonry structure at different time were proposed by the simulation of single component. Additionally, the overpressure of shock wave, caving velocity and kinetic energy were obtained. It shows that the caving can speed up to a maximum value of 152 m/s with the kinetic energy of 18 000 J, that means a great damage to personnel and equipment in the building. Under …


Study Of Synchronization For Fractional-Order Hyperchaotic System And Its Application In Secure Communication, Xue Wei, Jinkang Xu, Hongyan Jia Aug 2020

Study Of Synchronization For Fractional-Order Hyperchaotic System And Its Application In Secure Communication, Xue Wei, Jinkang Xu, Hongyan Jia

Journal of System Simulation

Abstract: A unidirectionally coupled synchronization method was adopted to design and implement the synchronization for the reported commensurate fractional-order hyperchaotic system, and its correctness and effectiveness were analyzed in theory. Moreover, taking an example of 3.6-order hyperchaotic system, analog circuits were designed to implement the fractional-order hyperchaotic system and its unidirectionally coupled synchronization with the frequency-domain approximation method based on Bode diagram. By conducting the circuit implementation, it is found that the results of the circuit implementation are in good agreement with those of the numerical simulation, which demonstrates the feasibility of the synchronization. On this basis, a secure communication …


Dynamic Simulation Of Single Abrasive Grain Cutting Tc4 Based On Sph Method, Wang Yan, Wang Shuai, Jianguo Liu, Xiong Wei Aug 2020

Dynamic Simulation Of Single Abrasive Grain Cutting Tc4 Based On Sph Method, Wang Yan, Wang Shuai, Jianguo Liu, Xiong Wei

Journal of System Simulation

Abstract: Considering the negative effects of mesh distortion on calculation accuracy in FEM simulation, a novel mesh free method named Smoothed Particle Hydrodynamics (SPH) method was employed to simulate the process of single CBN abrasive grain cutting TC4. Establishing a SPH model of TC4 workpiece and a FEM model of single abrasive grain with cutting edges similar to the real abrasive grain, the influences of cutting depth on grinding forces and chip formative process were studied systematically. The simulation results state that grinding forces enlarge with the increase of cutting depth, while grinding force ratio decreases. And TC4 chip formative …


Fire Reconstruction Method Based On Les And Linear Programming, Guangyao Yao, Peizhong Yang, Tan Xun Jul 2020

Fire Reconstruction Method Based On Les And Linear Programming, Guangyao Yao, Peizhong Yang, Tan Xun

Journal of System Simulation

Abstract: A method based on LES and linear programming was proposed for the numerical construction of fire accident. In the simulation with LES method, all the quantities were decomposed into large-scale components and small-scale components. For large-scale components, the direct simulation method was used. For small-scale components, the subgrid model was used. The LES method could improve the simulation accuracy. In the linear programming method, the parameters were locally linearized to solve the optimization problem. It could improve the simulation efficiency. The method was applied to the numerical reconstruction of a wholesale market fire in Shanghai. The spread of fire …


Numerical Simulation Of Hot And Cold Fluids Mixing In A Tee-Junction, Wenli Wei, Yunfei Hong, Shipeng Shao, Yuling Liu Jul 2020

Numerical Simulation Of Hot And Cold Fluids Mixing In A Tee-Junction, Wenli Wei, Yunfei Hong, Shipeng Shao, Yuling Liu

Journal of System Simulation

Abstract: Flow and heat transfer model in tee junction was established and the 3D RNG k-ε turbulence model was completed to simulate the process of mixing and capture the information of velocity and temperature. The simulation results and measured data of the mean value of velocity and temperature were analyzed and compared, and are in a good agreement, which indicates that the RNG k-ε model combined with the heat transfer model can well simulate the hydraulic characteristics and heat transfer mechanism of hot and cold fluids in a tee junction. Furthermore, the upstream segment of a tee junction has two …


Numerical Simulation About Fuel Injection Source Location Impacting On Turbulent Combustion Process, Sun Hui, Guangcheng Cai, Jiang Lin, Shibo Wang Jul 2020

Numerical Simulation About Fuel Injection Source Location Impacting On Turbulent Combustion Process, Sun Hui, Guangcheng Cai, Jiang Lin, Shibo Wang

Journal of System Simulation

Abstract: Fuel injection source location has very important influence on combustion process. It determines the location of the furnace flame. The three dimensional model of the furnace was established by the numerical simulation method. Under different conditions, the fuel injection source location on the temperature field within the furnace, the pollutant concentration field, and the flow field distribution inside the furnace combustion process were investigated. The results were compared and analyzed. After analysis, the results show that the fuel injection source location from 1.1 ~ 1.5 meter process of change, the average temperature within the furnace continue to rise, the …


Numerical Simulation And Experimental Study Of Three-Dimensional Flow Field On Roots-Type Power Machine Based On Dynamic Mesh Technique, Yanjun Xiao, Yuxiang Liu, Dayuan Wang, Feng Hua, Chunxia Li Jul 2020

Numerical Simulation And Experimental Study Of Three-Dimensional Flow Field On Roots-Type Power Machine Based On Dynamic Mesh Technique, Yanjun Xiao, Yuxiang Liu, Dayuan Wang, Feng Hua, Chunxia Li

Journal of System Simulation

Abstract: A new roots-type power machine was recommended. As for it, the working fluid of low pressure waste heat according was simulated to both the different operating conditions and the different intake and exhaust pressure and flow, and the changing process of internal flow field over time period using dynamic mesh technique was simulated when the power machine was in rotating work. The pressure field, velocity field and mass flow rate with the simulation results were analyzed, thus reaching the optimum operating conditions and the key parameters of the roots-type power machine. A test platform and conducted field tests was …


Numerical Simulation For Influence Of Baffle Length On Hydraulic Characteristics In Radial Sedimentation Tanks, Wenli Wei, Zewei Zhang, Yunfei Hong, Yuling Liu Jul 2020

Numerical Simulation For Influence Of Baffle Length On Hydraulic Characteristics In Radial Sedimentation Tanks, Wenli Wei, Zewei Zhang, Yunfei Hong, Yuling Liu

Journal of System Simulation

Abstract: The VOF (volume of fluid) method was applied to track the free water surface, and the RNG turbulent model was used to close the two-phase flow time-averaged equations. The influence of inlet vertical baffle with different lengths on hydraulic characteristics in radial sedimentation tank was simulated and analyzed. The control equations were discretized using the finite volume method. Velocity and pressure were solved using the PISO (Pressure-Implicit with Splitting of Operators) algorithm. The research results show that: the long length feed flow baffle model has a smaller recirculation zone, better velocity field distribution than short length baffle, and the …


Study On Diffraction Effects Of Planar Underwater Shock Interaction With Rigid Quadrilateral Structure, Yuchun Li, Zhenru Gao, Bin Feng, Liu Qiang, Shen Wei Jul 2020

Study On Diffraction Effects Of Planar Underwater Shock Interaction With Rigid Quadrilateral Structure, Yuchun Li, Zhenru Gao, Bin Feng, Liu Qiang, Shen Wei

Journal of System Simulation

Abstract: Finite element simulation using LS-DYNA was performed to investigate the interaction of underwater planar shock wave and rigid quadrilateral structure. The characteristics of diffraction waves on both front and back surface of the rigid structure were analyzed and trace lines were gained. Vortex was formed near the corner of the structure diffracted by underwater shock with a void part of zero pressure existing in the local fluid region. Bulk cavitation near fluid-structure interface leads fluid pressure to drop to negative value, which is an important damage factor to merged structures. A derived pressure formulas of diffraction wave to rigid …


Numerical Simulation Of Cavitation And Failure Analysis In Hydraulic Loader, Mo Li, Yang Qi, Yumei Wang Jun 2020

Numerical Simulation Of Cavitation And Failure Analysis In Hydraulic Loader, Mo Li, Yang Qi, Yumei Wang

Journal of System Simulation

Abstract: Using software CFX with SST κ-ω model and Rayleigh-Plesset cavitation model, the numerical simulation of 3-D steady flow with water liquid and water vapour two phases in whole flow passage of hydraulic loader was conducted. The influences of different parameters (inlet flow rate, rotational speed and blade angle) on cavitation of hydraulic loader were studied. The results show that, under small flow rate, large blade angle (≥60°) and low speed (≤3 000 r/min), cavitation is light. At different working conditions, where cavitation appears in radial direction of position is the same. The cavitation mainly distributes where the r/R …


Numerical Simulation Of Aluminum Foam Cushion Performance Analysis On Set-Forward Overload Of Fuze, Kuahai Yu, Xuhui Zhang, Hongyu Xu, Li Rong, Xingguo Kang Jun 2020

Numerical Simulation Of Aluminum Foam Cushion Performance Analysis On Set-Forward Overload Of Fuze, Kuahai Yu, Xuhui Zhang, Hongyu Xu, Li Rong, Xingguo Kang

Journal of System Simulation

Abstract: Buffering protect of fuze under high-speed impact was realized using aluminum foam gasket with special pore structure, and numerical simulation method to achieve the buffer validity analysis. Numerical model of three-layered concrete target projectile penetration was established, and the numerical model was validated to be accurate by comparing the fuze acceleration curves of simulation and experiment results. Numerical simulations were completed to predict the cushioning effect for different foamed aluminum structures. The result reveals that foamed aluminum cushioning can reduce the load of the fuze, and the foam's void ratio and thickness will significantly affect the cushioning performance, and …


Modeling And Numerical Simulation Of Micro-Tube Scale Effects In 3dp Process, Congping Chen, Xiaoyun Wang, Jieguang Huang, Li Bo Jun 2020

Modeling And Numerical Simulation Of Micro-Tube Scale Effects In 3dp Process, Congping Chen, Xiaoyun Wang, Jieguang Huang, Li Bo

Journal of System Simulation

Abstract: Wall slip and viscous dissipation are two main scale effects in 3DP (Three dimensional printing) process, which has influences on the material's flow properties and thermophysical properties and the printing quality. According to the two phenomena above, theoretic models of wall slip and viscous dissipation were established, respectively, and the software Polyflow was used to study the two scale effects and their interactions with molten ABS in micro-tubes of different radius. Simulation results show that wall slip level increases with the slip coefficient decreasing, and material's velocity decreases with the increase of tube radius; Viscous dissipation level decreases …


Numerical Simulation On Hydraulic Characteristics Of Free Hydraulic Jump On Corrugated Beds Of Stilling Basin, Wenli Wei, Yunfei Hong, Yuling Liu Jun 2020

Numerical Simulation On Hydraulic Characteristics Of Free Hydraulic Jump On Corrugated Beds Of Stilling Basin, Wenli Wei, Yunfei Hong, Yuling Liu

Journal of System Simulation

Abstract: The VOF (volume of fluid) method was applied to track the free water surface, and the RNG k–ε turbulent model was used to close the two-phase flow time-averaged equations. The conditions properties of free hydraulic jumps on corrugated beds with a stilling basin under 9 kinds of conditions were studied by numerical simulation. Simulation research results show: There are vortexes generated by corrugated beds surfaces, rotating in the clockwise direction. The pressure distribution on corrugated beds in hydraulic jump region appears a wavy change, and the difference between the pressure values at adjacent crest and trough gradually decreases along …


Numerical Simulation Of Diffusion Regularity Of Co In Fire Smoldering Phase In Aircraft Cabin, Jiaquan Lin, Ruiting Wang, Pi Jun, Ma Min, Jianzhong Yang Jun 2020

Numerical Simulation Of Diffusion Regularity Of Co In Fire Smoldering Phase In Aircraft Cabin, Jiaquan Lin, Ruiting Wang, Pi Jun, Ma Min, Jianzhong Yang

Journal of System Simulation

Abstract: In order to study the impact of the cabin air conditioning supply velocity on CO diffusing in the fire smoldering phase and the effect of the transportation of CO to human body, a simulation model of A320 aircraft cabin was established, and velocity field and CO concentration field under the different air supply velocity were simulated based on the fluid dynamics control equations. The relationship between the air conditioning supply velocity and the value of CO concentration as well as the diffusion area was obtained by the analysis of the transportation of CO in different directions. The drainage efficiency …


Inertia Effect In Dynamic Tensile Tests Of Concrete-Like Materials, Zhang Shu, Yubin Lu, Dongmei Zhao, Chen Xing Jun 2020

Inertia Effect In Dynamic Tensile Tests Of Concrete-Like Materials, Zhang Shu, Yubin Lu, Dongmei Zhao, Chen Xing

Journal of System Simulation

Abstract: The different understanding on the influential degree of the inertial effect does exist among researchers, and it has not been uniformly defined in dynamic tensile tests. The finite element numerical simulation method was employed to analyze the three typical dynamic tensile tests, without considering the real strain-rate effect in these models, where a constitutive model only considered the influence of hydrostatic pressure was used for modeling the specimen in these models. It is found that the dynamic tensile strength of concrete specimens in the three models mentioned is strengthened with the increase of loading strain-rate, owing to the …


Survey Of Studies On Numerical Simulations Of Optical-Wave Propagation In Atmospheric Turbulence, Bin Ren, Chunyi Chen, Huamin Yang Jun 2020

Survey Of Studies On Numerical Simulations Of Optical-Wave Propagation In Atmospheric Turbulence, Bin Ren, Chunyi Chen, Huamin Yang

Journal of System Simulation

Abstract: The complicated random behavior of atmospheric turbulence makes it difficult to verify the theories of optical-wave propagation in atmospheric turbulence by conducting experimental measurements. The parameters used in numerical simulations can be easily controlled; therefore numerical simulations have been used as another important tool to investigate the optical-wave propagation in atmospheric turbulence. Based on the existing literature, both the theoretical models and numerical generating methods for random phase screens of atmospheric turbulence are surveyed, and the spatial sampling constraints for numerical simulations of optical propagation in atmospheric turbulence were summarized. By comprehending the existing results, it has been pointed …


Stability Of Electrically Conducting Fluid Flow In Channel Under Magnetic Field, Dong Shuai, Lishuai Liu, Xuemin Ye Jun 2020

Stability Of Electrically Conducting Fluid Flow In Channel Under Magnetic Field, Dong Shuai, Lishuai Liu, Xuemin Ye

Journal of System Simulation

Abstract: The stability of conducting fluid flow in a channel under a vertical magnetic field was simulated by non-normal modal stability analysis. The perfect conductivity assumption of the channel wall was employed in the model, and its effect on the stability problem was considered. The results show that when the Hartmann number Ha is larger than 9, the two opposite Hartmann boundary layers are essentially independent of each other; however, when the Hartmann number Ha is smaller than 9, there are still residual interactions between the two opposite Hartmann boundary layers, which has influences on the stability of the flow. …


Simulation Analysis On Ballistic Deflection Of Projectile Obliquely Penetrating Into Concrete, Jianfeng Xue, Peihui Shen, Xiaoming Wang Jun 2020

Simulation Analysis On Ballistic Deflection Of Projectile Obliquely Penetrating Into Concrete, Jianfeng Xue, Peihui Shen, Xiaoming Wang

Journal of System Simulation

Abstract: In order to study the trajectory deflection law of projectiles obliquely penetrating into concrete targets, based on the theory of rigid body kinematics and cavity expansion, the penetration motion differential equations of ogive-nosed projectile were established. The variation rules of trajectory offset and invasion depth were given in different initial conditions through the programming calculation and numerical simulation by MATALB and ANSYS-LYNA software. The calculation results agree well with experimental data. The results show that the influence of penetration depth and deflection angle increase with the oblique angle increasing. The influence of ballistic deflection decreases with the …


Research On Cavitation Evolution Model In Venturi Tube, Guihua Han, Yanan Liu, Junpeng Shao, Cijun Zhang Feb 2020

Research On Cavitation Evolution Model In Venturi Tube, Guihua Han, Yanan Liu, Junpeng Shao, Cijun Zhang

Journal of System Simulation

Abstract: The dynamic cavitation model of venturi tube air-water two-phase flow was established according to the time variation of air precipitation and digestion process in water. FLUENT three-dimension numerical simulation were studied to simulate the air-water two-phase flow, and the variation law of venturi tube throat diameter and inlet pressure on vapor volume fraction were obtained. The results of numerical simulation and experiments show that the vapor volume fraction increases following the increase of the inlet pressure. If the throat diameter is increased, the inlet pressure can be increased as the compensation to achieve the same cavitation effect. The …


Numerical Simulation Analysis Of Anti-Blast Impact Of Underground Rescue Capsule Based On Ls-Dyna, Zhang Fan, Yuanhua Yang, Xiaoxu He, Deng Yu Dec 2019

Numerical Simulation Analysis Of Anti-Blast Impact Of Underground Rescue Capsule Based On Ls-Dyna, Zhang Fan, Yuanhua Yang, Xiaoxu He, Deng Yu

Journal of System Simulation

Abstract: Aiming at the strength problem of the underground rescue cabin under explosion impact load, a finite element model of overall explosion impact load and fluid-solid coupling structure response is established in transient dynamic soft LS-DYNA. The flow field impact load is generated by explosion algorithm, and the propagation of the impact load in the air is calculated. The dynamic response of the rescue cabin structure under the impact load is calculated by the fluid-solid coupling method. The results show that the maximum load occurs on the end surface closest to the explosion source, and the structural deformation is small …


Fatigue Life Prediction Of Turbine Blades Based On Qar Data, Pi Jun, Shuwei Gao, Jiangbo Huang, Huang Lei, Ma Long Dec 2019

Fatigue Life Prediction Of Turbine Blades Based On Qar Data, Pi Jun, Shuwei Gao, Jiangbo Huang, Huang Lei, Ma Long

Journal of System Simulation

Abstract: Based on the characteristics of the high-pressure turbine blade, a numerical simulation method for the actual load spectrum of the high-pressure turbine blade of the civil aircraft engine based on the QAR data is proposed. The actual service load spectrum of the engine recorded during aircraft flight is extracted from the QAR data; the time history of centrifugal force, aerodynamic force and thermal stress of the turbine blade in actual use is obtained by means of finite element simulation; and with life prediction model, the actual service life of the blade is estimated. This method provides a reliable …


Numerical Simulation Of Spread And Infection Risk Of Respiratory Pathogens In The Aircraft Cabin, Jiaquan Lin, Fengshan Sun, Yachong Li Dec 2019

Numerical Simulation Of Spread And Infection Risk Of Respiratory Pathogens In The Aircraft Cabin, Jiaquan Lin, Fengshan Sun, Yachong Li

Journal of System Simulation

Abstract: In order to study the transmission law of respiratory pathogens through the breath of the sick passengers in the aircraft cabin and reduce the risk of infection, the numerical model of respiratory pathogens spread in Boeing737 economy cabin is established. The dynamic propagation process of respiratory pathogens released by the sick passenger is simulated. The risk of infection for other passengers is obtained. Taking SEI (Susceptible Exposure Index) as an evaluation index,,the seats with the least risk of infection for other passengers are obtained based on the simulated data by changing the seats of the sick passengers. Some seats …


Numerical Simulation For Airflow Field Around Car Wheels, Haibo Huang, Xudong Yu, Qingguo Liu, Zhang Tao, Jianan Dong Nov 2019

Numerical Simulation For Airflow Field Around Car Wheels, Haibo Huang, Xudong Yu, Qingguo Liu, Zhang Tao, Jianan Dong

Journal of System Simulation

Abstract: The airflow field characteristics around the wheels have great influence on the flying of road dust and tire wear particles. Using the rotating wall boundary technology, an aerodynamic model of the vehicle-tire was built and verified. The airflow field around the wheels was obtained. The results show that the two airflows between the wheel and the wheel guard meet leading to the vortex. The airflows mainly overflow near the intersection. Due to the significant pumping effects, the airflow tends to fly to outside and upward near the front and rear wheels, respectively. In the …


Simulation Of Gas-Liquid Mixing Flow In A Stirred Tank With Inverted Umbrella-Type Surface Aerator, Wenli Wei, Weili Lou, Panpan Li, Yuling Liu Nov 2019

Simulation Of Gas-Liquid Mixing Flow In A Stirred Tank With Inverted Umbrella-Type Surface Aerator, Wenli Wei, Weili Lou, Panpan Li, Yuling Liu

Journal of System Simulation

Abstract: The way of computational fluid dynamics with k-ε turbulence model as well as multiple reference frame method was used to simulate the hydraulic characteristics of gas-liquid mixing flow in a stirred tank installed with an inverted umbrella-type surface aerator. The inverted umbrella aerator consists of eight blades, and rotates at 5.23rad/s. The main purpose of this simulation is to study the distributions of air volume fraction and characteristics of mixing flow. The simulation results show that the distribution of the mixing flow is symmetrical; the change rules of the gas distribution at different positions along the axis direction are …


Finite Element Numerical Simulation Of Pre-Damaged Reinforced Concrete Beam, Jiaquan Wu, Hongyan Li, Ye Fei, Xinyu Zhang, Kun Ma Jan 2019

Finite Element Numerical Simulation Of Pre-Damaged Reinforced Concrete Beam, Jiaquan Wu, Hongyan Li, Ye Fei, Xinyu Zhang, Kun Ma

Journal of System Simulation

Abstract: Based on the theory of model analysis, the general variation of model parameters, such as the structure natural frequency, displacement mode, curvature mode and strain mode etc.model of reinforced concrete beams with different damage locations and different damage states are reversely studied by finite element numerical simulation with the pre-damaged reinforced concrete beam structure as the research object, model and the aptability, sensitivity in the reinforced concrete structure damage identification are discussed. The results show that the frequency and displacement mode can not effectively reflect the existence of structural damage, but curvature mode and strain mode can reflect the …


Mechanism Of Biofouling Control On Micro-Structured Surface, Chunxi Li, Quanxi Xue, Zhang Shuo, Xuemin Ye Jan 2019

Mechanism Of Biofouling Control On Micro-Structured Surface, Chunxi Li, Quanxi Xue, Zhang Shuo, Xuemin Ye

Journal of System Simulation

Abstract: Changing the wall microstructure geometry can improve the performance of surface antifouling and selfcleaning. A 3D numerical simulation of microfluidic in the near-wall region attached with microorganisms is performed with Fluent, and the kinetic and dynamic characteristics of fluid in the near- wall region are examined. The inherent mechanism of antifouling on microwell surfaces is discussed. Results reveal that streamwise vortices are formed in the microwells, thus the distinctly periodic fluctuations of velocity, strain rate and wall shear stress on microwell surfaces are exhibited, resulting in the interference on microorganisms migration and the harder adhesion of microorganisms to …