Experiment and Numerical Simulation of Extrudate Swell in the Polymer Extrusion Process

2011 ◽  
Vol 314-316 ◽  
pp. 401-404 ◽  
Author(s):  
Min Zhang ◽  
Chuan Zhen Huang ◽  
Guo Wen Chen ◽  
Yu Xi Jia
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Three Dimensional ◽  
Simulation Method ◽  
Extrusion Process ◽  
High Speed Photography ◽  
The Finite Element Method ◽  
Polymer Extrusion ◽  
Extrudate Swell ◽  
Rate Profile

The extrudate swell of the polymer extrusion process was studied with the experiment and simulation method. The extrudate swell process was recorded by the high-speed photography apparatus. The swell rate at the different time was calculated. It is found that the extrudate swell rate increase at the first five seconds. The maximum swell rate is about 4.37%. The three-dimensional numerical simulation model of the experiment die path was founded. The extrusion process including the extrudate swell was simulated used the Finite Element Method. Such simulated results as the velocity vector, the shear rate profile and the end of the swell zone were analyzed. The extrudate swell end got by the simulation is similar with the experiment result.

The Inverse Prediction for Profile Extrusion Die Based on the Finite Element Method

2014 ◽  
Vol 941-944 ◽  
pp. 2332-2335 ◽  
Author(s):  
Min Zhang ◽  
Chuan Zhen Huang ◽  
Yu Xi Jia ◽  
Jin Long Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Polymer Melt ◽  
Simulation Method ◽  
Extrusion Process ◽  
The Finite Element Method ◽  
Polymer Extrusion ◽  
Extrudate Swell ◽  
Extrusion Die ◽  
Element Method

Considering the extrudate swell, the polymer extrusion process was calculated by the inversed simulation based on the visco-elastic ecology theory. The fluid characteristics of the polymer melt were described by the Phan-Thien and Tanner (PTT) model. The Finite Element Method was used. Based on the simulation data, the extrusion die lips were analyzed. So it is feasible to design the polymer extrusion die lips using inversed simulation method.

Jet motion and fiber properties arising from a parallel electric field in melt-electrospinning

2020 ◽  
pp. 004051752096419
Author(s):  
Xueqin Li ◽  
Yuansheng Zheng ◽  
Xiaoqi Mu ◽  
Binjie Xin ◽  
Lantian Lin
Keyword(s):  
Electric Field ◽  
High Speed ◽  
Three Dimensional ◽  
Great Influence ◽  
Simulation Method ◽  
High Speed Photography ◽  
Outer Diameter ◽  
Electrospinning Technique ◽  
Fiber Properties ◽  
Melt Electrospinning

It is well known that the electric field has a great influence on the diameter and properties of fiber prepared via the melt-electrospinning technique. In this paper, two parallel metal discs were introduced to create a controllable electric field in the experiments. In addition, a three-dimensional electric field was calculated by the numerical simulation method and the jet motion was captured by taking advantage of high-speed photography technology. The influences of electric field distribution on the fiber jet, fiber diameter, fiber mat area and fiber crystallinity were studied in an in-depth and systematical manner. Both whipping amplitude and whipping frequency were also used to describe the characteristics of the jet. The above-mentioned results have proven that increasing the distance between the two parallel metal discs leads to the decrease of electric field intensity and the increase of electric field action time on the fiber, which together determine the diameter and crystallinity of the fiber. With the increase of the outer diameter of the upper disc, the distribution of the electric field becomes more uniform, making it capable of steadily controlling the behavior of the jet, and thus effectively reducing the diameter of the fiber and improving the crystallinity of the fiber.

Security Analysis on Single-Screw Extrusion Process of Solid Propellant by Numerical Simulation

2014 ◽  
Vol 997 ◽  
pp. 605-609
Author(s):  
Zhong Qi He ◽  
Ke Zhou ◽  
Shu Pan Yin
Keyword(s):  
Numerical Simulation ◽  
Solid Propellant ◽  
High Speed ◽  
Security Analysis ◽  
Simulation Method ◽  
Extrusion Process ◽  
Rheological Parameters ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Screw Extrusion

Solid propellants are flammable, explosive, which maybe initiated unexpectedly under specific excitation conditions through high-speed screwing. Though single-screw extrusion process for solid propellant occurred a large proportion accidents, the rheological parameters of the propellant material were difficult to get yet, which affects the process safety greatly. In this paper, the CFD software, POLYFLOW, and a numerical simulation method were adopted to investigate the rheological parameters in single-screw extrusion process of solid propellant. By analyzing the rheological state of a solid propellant in the screw extrusion process, the applicable numerical model was established with a substitute material for the propellant. As a result, distributions of key parameters, such as material temperature, pressure, viscosity, were obtained. The simulation shows that the material has relatively higher pressure, temperature and smaller viscosity at the screw edge, where solid propellant components were mixing and plasticizing severely, also where needs pay much attention to for safety reasons.

scholarly journals Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

2020 ◽  
Vol 12 (1) ◽  
pp. 703-717
Author(s):  
Yin Wei ◽  
Wang Jiaqi ◽  
Bai Xiaomin ◽  
Sun Wenjie ◽  
Zhou Zheyuan
Keyword(s):  
Numerical Simulation ◽  
Control Strategy ◽  
Three Dimensional ◽  
Simulation Method ◽  
Mine Pressure ◽  
Hydraulic Support ◽  
Transition Area ◽  
Pressure Concentration ◽  
Strata Behavior ◽  
And Control

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

scholarly journals Study of the Effect of Centrifugal Force on Rotor Blade Icing Process

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhengzhi Wang ◽  
Chunling Zhu
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Force ◽  
Rotor Blade ◽  
Flow Direction ◽  
Three Dimensional ◽  
Simulation Method ◽  
Two Phase ◽  
Numerical Simulation Method ◽  
Calculation Results ◽  
Flow Field Characteristics

In view of the rotor icing problems, the influence of centrifugal force on rotor blade icing is investigated. A numerical simulation method of three-dimensional rotor blade icing is presented. Body-fitted grids around the rotor blade are generated using overlapping grid technology and rotor flow field characteristics are obtained by solving N-S equations. According to Eulerian two-phase flow, the droplet trajectories are calculated and droplet impingement characteristics are obtained. The mass and energy conservation equations of ice accretion model are established and a new calculation method of runback water mass based on shear stress and centrifugal force is proposed to simulate water flow and ice shape. The calculation results are compared with available experimental results in order to verify the correctness of the numerical simulation method. The influence of centrifugal force on rotor icing is calculated. The results show that the flow direction and distribution of liquid water on rotor surfaces change under the action of centrifugal force, which lead to the increasing of icing at the stagnation point and the decreasing of icing on both frozen limitations.

Calculation and Design Method Study of the Coil-Wound Heat Exchanger

2014 ◽  
Vol 1008-1009 ◽  
pp. 850-860 ◽  
Author(s):  
Zhou Wei Zhang ◽  
Jia Xing Xue ◽  
Ya Hong Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
Design Method ◽  
Fluid Velocity ◽  
Exchange Process ◽  
Three Dimensional ◽  
Simulation Method ◽  
Physical Parameters ◽  
Numerical Result

A calculation method for counter-current type coil-wound heat exchanger is presented for heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of wound bundles. By controlling the inlet fluid velocity varying in coil-wound heat exchanger to program and calculate the iterative process. The calculation data is analyzed by comparison of numerical result and the unit three dimensional pipe bundle model was built. Studies show that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration in coil-wound heat exchanger. This method can be applied to the physical modeling and heat transfer calculation of pipe bundles in coil wound heat exchanger, program to calculate the complex heat transfer changing with velocity and other parameters, and optimize the overall design and calculation of spiral bundles.

Age-Related Differences in Throwing Techniques Used by the Catcher in Baseball

1994 ◽  
Vol 6 (3) ◽  
pp. 225-235 ◽  
Author(s):  
Shinji Sakurai ◽  
Bruce Elliott ◽  
J. Robert Grove
Keyword(s):  
High Speed ◽  
High Performance ◽  
Age Groups ◽  
Three Dimensional ◽  
Transformation Method ◽  
High Speed Photography ◽  
Two Phase ◽  
Ball Speed ◽  
Age Related ◽  
Release Speed

Three-dimensional (3-D) high speed photography was used to record the overarm throwing actions of five open-age, four 18-year-old, six 16-year- old, and six 14-year-old high-performance baseball catchers. The direct linear transformation method was used for 3-D space reconstruction from 2-D images of the catchers throwing from home plate to second base recorded using two phase-locked cameras operating at a nominal rate of 200 Hz. Selected physical capacity measures were also recorded and correlated with ball release speed. In general, anthropometric and strength measures significantly increased through the 14-year-old to open-age classifications, while a range of correlation coefficients from .50 to .84 was recorded between these physical capacities and ball speed at release. While many aspects of the kinematic data at release were similar, the key factors of release angle and release speed varied for the different age groups.

The Research on Steering Fracture Numerical Simulation

2013 ◽  
Vol 734-737 ◽  
pp. 1488-1492
Author(s):  
Zhen Yu Liu ◽  
Li Hong Yao ◽  
Hu Zhen Wang ◽  
Cui Cui Ye
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
Simulation Method ◽  
Production Performance ◽  
Phase Flow ◽  
Water Production ◽  
Two Phase ◽  
Fractured Well

The fractures after artificial steering fracturing appear in shades of curved surface. Aiming at the problem of steering fracture, in the paper, numerical simulation method under the condition of three-dimensional two-phase flow is presented based on finite element method. In this method, of steering fracture was achieved by adopting surface elements fractures and tetrahedron elements to describe formation. By numerical simulation, the change rule of oil and water production performance of steering fractures can be calculated, and then the steering fracture parameters can be optimized before fracturing. A new method was supplied for the numerical simulation of artificial fractured well.

scholarly journals Numerical Simulation for Engine/Airframe Interaction Effects of the BWB300 on Aerodynamic Performances

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Gang Yu ◽  
Dong Li ◽  
Yue Shu ◽  
Zeyu Zhang
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Separated Flow ◽  
Simulation Method ◽  
Interaction Effects ◽  
Surface Flow ◽  
Concept Design ◽  
Aerodynamic Forces ◽  
Low Speed ◽  
Aerodynamic Performances

The engine/airframe interaction effects of the BWB300 on aerodynamic performances were analyzed by using the numerical simulation method. The BWB300 is a 300-seat Blended Wing Body airplane designed by the Airplane Concept Design Institute of Northwestern Polytechnical University. The engine model used for simulation was simplified as a powered nacelle. The results indicated the following: at high speed, although the engine/airframe interaction effects on the aerodynamic forces were not significant, the airframe’s upper surface flow was greatly changed; at low speed, the airframe’s aerodynamic forces (of the airplane with/without the engine) were greatly different, especially at high attack angles, i.e., the effect of the engine suction caused the engine configuration aerodynamic forces of the airframe to be bigger than those without the engine; and the engine’s installation resulting in the different development of flow separation at the airframe’s upper surface caused greater obvious differences between the 2 configurations at high angles and low speed. Moreover, at low-speed high attack angles, the separated flow from the blended area caused serious distortion at the fan inlet of the engine.

Numerical Simulation of Ultrasonic Shear Wave Propagation Based on the Finite Element Method

2014 ◽  
Vol 488-489 ◽  
pp. 926-929 ◽  
Author(s):  
Jian Ma ◽  
Yang Zhao ◽  
Ji Hua Sun ◽  
Shuai Liu
Keyword(s):  
Numerical Simulation ◽  
Shear Wave ◽  
Present Method ◽  
Steel Plate ◽  
Mode Conversion ◽  
Simulation Method ◽  
The Finite Element Method ◽  
Propagation Process ◽  
The Time Domain ◽  
Ultrasonic Shear

The present paper provided a kind of numerical simulation method which was employed to guide the process of ultrasonic nondestructive testing and analyze the inspection results. The simulation concerning the propagation process of shear wave in the steel plate was carried out using the ANSYS, according to the mechanism of ultrasonic mode conversion. Then, the frequency, velocity and refraction angle were extracted from the time-domain date in order to verify the simulation. It is found that the result of simulation agrees well with the theoretical one, which shows that the present method is correct and reliable.

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