Study on the Flow Behavior in a Tubular Cavity during Water-Assisted Injection Molding

2010 ◽  
Vol 154-155 ◽  
pp. 359-362
Author(s):  
Tang Qing Kuang
Keyword(s):  
Injection Molding ◽  
Control Volume ◽  
Flow Behavior ◽  
Polymer Melt ◽  
Bulk Temperature ◽  
Curved Pipe ◽  
Fluid Behavior ◽  
Simulation Results ◽  
Injection Location ◽  
Good Agreement

A simulation model for the filling of a tubular cavity during water assisted injection molding is proposed. The polymer melt and water are assumed to be incompressible and to follow a Hele-Shaw fluid behavior. The finite element/finite difference/control volume methods are adopted for numerical simulation of the melt front, pressure at injection location variation, water thickness fraction and bulk temperature about a curved pipe, the simulation results have good agreement with the results presented in the former experiment. In comparison with the simulation result of gas-assisted injection molding, water assisted injection molding can give parts with thinner and more uniform walls and more rapid cooling.

Strain Analysis on Weld Zone of Tailor Welded Blanks in the Case of Welded Seam Cracking

2010 ◽  
Vol 154-155 ◽  
pp. 355-358
Author(s):  
Qiao Sheng Hu ◽  
Feng Ni ◽  
Jian Ping Lin
Keyword(s):  
Injection Molding ◽  
Control Volume ◽  
Weld Zone ◽  
Strain Analysis ◽  
Polymer Melt ◽  
Bulk Temperature ◽  
Curved Pipe ◽  
Tailor Welded Blanks ◽  
Fluid Behavior ◽  
Welded Seam

A simulation model for the filling of a tubular cavity during water assisted injection molding is proposed. The polymer melt and water are assumed to be incompressible and to follow a Hele-Shaw fluid behavior. The finite element/finite difference/control volume methods are adopted for numerical simulation of the melt front, pressure at injection location variation, water thickness fraction and bulk temperature about a curved pipe, the simulation results have good agreement with the results presented in the former experiment. In comparison with the simulation result of gas-assisted injection molding, water assisted injection molding can give parts with thinner and more uniform walls and more rapid cooling.

Study on the Flow Behavior in Thin Cavity during Water-Assisted Injection Molding

2011 ◽  
Vol 467-469 ◽  
pp. 80-83
Author(s):  
Tang Qing Kuang ◽  
Kun Han
Keyword(s):  
Injection Molding ◽  
Control Volume ◽  
Fluid Model ◽  
Flow Behavior ◽  
Experimental Result ◽  
Bulk Temperature ◽  
Injection Molding Process ◽  
Molding Process ◽  
Injection Location ◽  
Good Agreement

A numerical simulation model for the flow behavior of fluids in thin cavity during water assisted injection molding process is built up by adopting general Newtonian fluid model for the filling stage and non-Newtonian and compressible fluid model for the packing stage separately. Finite element/finite difference/control volume methods are adopted for the simulation of melt front, pressure variation at injection location, water thickness fraction and bulk temperature about a plate with trapezoidal cross-section. The simulated melt front location and shape have good agreement with experimental result. In comparison with the simulation results of conventional injection molding, it turns out that water assisted injection molding can obtain parts with low pressure requirement, perfect surface quality and rapid cooling.

Simulation of Spouted Bed Using a Eulerian Multiphase Model

2005 ◽  
Vol 498-499 ◽  
pp. 270-277 ◽  
Author(s):  
Claudio Roberto Duarte ◽  
Valéria V. Murata ◽  
Marcos A.S. Barrozo
Keyword(s):  
Control Volume ◽  
Flow Behavior ◽  
Cfd Modeling ◽  
Gas Flows ◽  
Present Calculation ◽  
Multiphase Model ◽  
Spouted Bed ◽  
Particle Coating ◽  
Spouted Beds ◽  
Good Agreement

Spouted bed systems have emerged as very efficient fluid-particle contactors and find many applications in the chemical and biochemical industry. Some important applications of spouted beds include coal combustion, biochemical reactions, drying of solids, drying of solutions and suspensions, granulation, blending, grinding, and particle coating. An extensive overview can be found in Mathur and Epstein[1]. The pattern of solid and gas flows in a spouted bed was numerically simulated using a CFD modeling technique. The Eulerian-Eulerian multifluid modeling approach was applied to predict gas-solid flow behavior. A commercially available, control-volume-based code FLUENT 6.1 was chosen to carry out the computer simulations. In order to reduce computational times and required system resources, the 2D axisymmetric segregated solver was chosen. The typical flow pattern of the spouted bed was obtained in the present calculation. The simulated velocity and voidage profiles presented a good agreement qualitative and quantitative with the experimental results obtained by He et al. [4].

Dynamic Simulation and Graphics for the Injection Molding of Three-Dimensional Thin Parts

1986 ◽  
Vol 7 (1) ◽  
pp. 21-46 ◽  
Author(s):  
V.W. Wang ◽  
C.A. Hieber ◽  
K.K. Wang
Keyword(s):  
Injection Molding ◽  
Delivery System ◽  
Pressure Field ◽  
Control Volume ◽  
Polymer Melt ◽  
Time Step ◽  
One Dimensional ◽  
Molded Part ◽  
Injection Molded ◽  
Control Volumes

Summary A numerical formulation is presented for simulating the injection-molding filling of thin cavities, together with the delivery system, in three dimensions. The modelling is based on generalized Hele-Shaw flow for an inelastic, non-Newtonian fluid under non-isothermal conditions, which has been previously shown to be satisfactory for simulating the polymer melt flow in the cavities. A hybrid numerical scheme is employed in which the injection-molded part is described by two-dimensional triangular elements, provided that the cavity thickness is relatively thin, and the gapwise and time derivatives are expressed in terms of finite differences. The elements are flat, but can have any orientation in 3-D space to approximate the surfaces of the molded part. A triangular element is further divided into three sub-areas by joining the centroid of the element to the mid-point of its three edges. The control volume associated with any vertex node is then defined as the sum of all such sub-areas containing that node multiplied by each respective thickness. The numerical calculation of the flow field (or the pressure field) is based on the conservation of mass in each control volume which, at any given instant, can be either empty, partially filled, or totally filled with polymer melt. The melt-front location is defined by the partially filled control volumes which are allowed to advance in the calculation such that one partially filled control volume gets filled during each properly chosen time step with all of its adjacent empty control volumes then becoming new melt-front control volumes. The pressure and temperature are calculated at each time step, with the resulting pressure field determining the flow direction which, in turn, determines which partially-filled control volume should get filled during the following time step. One-dimensional flow segments, such as circular or non-circular tubes, can also be employed to represent the delivery system. This one-dimensional flow is coupled with the cavity filling in order to form a complete simulation of the mold filling. Comparisons with experiment have been made for a rectangular cavity with three inserts. The results show good agreement in terms of pressure traces and weldline locations. Another complex 3-D injection molded part has also been modelled to demonstrate the capability of the analysis.

Integrated Simulation of Fluid Flow and Heat Transfer in Injection Molding for the Prediction of Shrinkage and Warpage

1993 ◽  
Vol 115 (1) ◽  
pp. 37-47 ◽  
Author(s):  
H. H. Chiang ◽  
K. Himasekhar ◽  
N. Santhanam ◽  
K. K. Wang
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Injection Molding ◽  
Data Exchange ◽  
Control Volume ◽  
Polymer Melt ◽  
Coupled Analysis ◽  
Injection Molding Process ◽  
Integrated Simulation ◽  
Flow And Heat Transfer

This work employs a coupled analysis of the fluid flow and heat transfer in the polymer melt during the filling and post-filling stages of the injection-molding process and of mold cooling/heating which occurs during the entire process. Polymer melt analysis (PMA) has been carried out through a unified theoretical model implemented using a hybrid finite-element/finite-difference/control-volume numerical solution of the generalized Hele-Shaw flow of a compressible viscous fluid under non-isothermal conditions. Further, mold-cooling analysis (MCA) has been carried out utilizing a periodic heat conduction model implemented using a modified three-dimensional boundary-element method. To faithfully accommodate the effects of mold cooling on the fluid flow and heat transfer in the polymer melt, PMA and MCA have been coupled for appropriate data exchange and iterations carried out until a convergent solution for mold temperatures and for flow, pressure and temperatures within the polymer melt is obtained. The results obtained from this integrated simulation for different test cases have been compared with experimental data and a favorable agreement has been noticed. Using an illustrative example, the results are discussed in detail.

The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding

2003 ◽  
Vol 18 (4) ◽  
pp. 405-411 ◽  
Author(s):  
D. Watanabe ◽  
U. S. Ishiaku ◽  
T. Nagaoka ◽  
K. Tomari ◽  
H. Hamada
Keyword(s):  
Injection Molding ◽  
Flow Behavior ◽  
Core Material

scholarly journals Measuring Hydrometeors Using a Precipitation Microphysical Characteristics Sensor: Sampling Effect of Different Bin Sizes on Drop Size Distribution Parameters

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Xichuan Liu ◽  
Taichang Gao ◽  
Yuntao Hu ◽  
Xiaojian Shu
Keyword(s):  
Drop Size ◽  
Rain Rate ◽  
Monte Carlo Model ◽  
Rain Gauge ◽  
Sampling Schemes ◽  
Distribution Parameters ◽  
Optimum Sampling ◽  
Simulation Results ◽  
The Impact ◽  
Good Agreement

In order to improve the measurement of precipitation microphysical characteristics sensor (PMCS), the sampling process of raindrops by PMCS based on a particle-by-particle Monte-Carlo model was simulated to discuss the effect of different bin sizes on DSD measurement, and the optimum sampling bin sizes for PMCS were proposed based on the simulation results. The simulation results of five sampling schemes of bin sizes in four rain-rate categories show that the raw capture DSD has a significant fluctuation variation influenced by the capture probability, whereas the appropriate sampling bin size and width can reduce the impact of variation of raindrop number on DSD shape. A field measurement of a PMCS, an OTT PARSIVEL disdrometer, and a tipping bucket rain Gauge shows that the rain-rate and rainfall accumulations have good consistencies between PMCS, OTT, and Gauge; the DSD obtained by PMCS and OTT has a good agreement; the probability of N0, μ, and Λ shows that there is a good agreement between the Gamma parameters of PMCS and OTT; the fitted μ-Λ and Z-R relationship measured by PMCS is close to that measured by OTT, which validates the performance of PMCS on rain-rate, rainfall accumulation, and DSD related parameters.

scholarly journals Simulation and Experimental Study on Wear of U-Shaped Rings of Power Connection Fittings under Strong Wind Environment

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 735
Author(s):  
Songchen Wang ◽  
Xianchen Yang ◽  
Xinmei Li ◽  
Cheng Chai ◽  
Gen Wang ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Adhesive Wear ◽  
Surface Hardness ◽  
Wear Depth ◽  
Strong Wind ◽  
Wear Model ◽  
Wind Environment ◽  
Simulation Results ◽  
Oxidation Wear ◽  
Good Agreement

The objective of this study was to investigate the wear characteristics of the U-shaped rings of power connection fittings, and to construct a wear failure prediction model of U-shaped rings in strong wind environments. First, the wear evolution and failure mechanism of U-shaped rings with different wear loads were studied by using a swinging wear tester. Then, based on the Archard wear model, the U-shaped ring wear was dynamically simulated in ABAQUS, via the Umeshmotion subroutine. The results indicated that the wear load has an important effect on the wear of the U-shaped ring. As the wear load increases, the surface hardness decreases, while plastic deformation layers increase. Furthermore, the wear mechanism transforms from adhesive wear, slight abrasive wear, and slight oxidation wear, to serious adhesive wear, abrasive wear, and oxidation wear with the increase of wear load. As plastic flow progresses, the dislocation density in ferrite increases, leading to dislocation plugs and cementite fractures. The simulation results of wear depth were in good agreement with the test value of, with an error of 1.56%.

Upward Vertical Two-Phase Flow Through an Annulus—Part II: Modeling Bubble, Slug, and Annular Flow

1992 ◽  
Vol 114 (1) ◽  
pp. 14-30 ◽  
Author(s):  
E. F. Caetano ◽  
O. Shoham ◽  
J. P. Brill
Keyword(s):  
Flow Pattern ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Bubble Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through ◽  
Physical Phenomena ◽  
Good Agreement

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.

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