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【英文摘要】
ABSTRACT
Magnesium alloys are metals which have high specific strength, low density and
high thermal conductivity. They are non-magnetic materials with very good
damping and EMI shielding capacities. These characteristics enable the
magnesium alloys to be used in the communication, electronic devices and many
other computer components. Among these applications, the chassis of notebook
computer becomes one of the prominent usages in recent years. The chassis are
usually thin-walled plate constructions, manufactured by die casting or semi-
solid forming process which encounters many difficulties.
In order to increase the yield of magnesium alloy in die casting, this study
simulate the thin-walled plate in die casting process with a commercial code
FLOW-3D, investigates the material flow in the die cavity, its solidification
in the mold and their relations to defects of the products. The gate system
effects on the results of the die casting products are also discussed.
From the simulation, it is found that for AZ91D magnesium alloy, the best die
casting parameter combination is: casting pressure 100 MPa, liquid flow speed
110 m/s, casting temperature 630℃ and mold temperature 240℃. This die
casting condition promotes lower temperature variation in mold cavity, which
in turn may lead to better yield.
One of the goals of simulation is to compare results obtained when particular parameters are changed. An easy way to compare results of different simulations is to use the plot overlay option available in the FLOW-PLOT and PLTFSI display utilities. Users running on UNIX and LINUX platforms will have to use PLTFSI.
In either case the first step is to open a flsgrf results file from Results, Custom. It is fairly straightforward to compare time history plots, 1D and 2D spatial plots from the same results file, since they can be directly overlaid. To overlay the two plots using PLTFSI, enter D n+m where n and m represent the plot numbers. In FLOW-PLOT you must change the option in the Control Panel from “single” to “overlay,” then click on the plots to be overlaid.
Comparing plots from two or more different flsgrf files requires an extra step. Let’s say you’d like to compare the temperature history at a particular point in the domain. The simplest method is to first open an flsgrf file containing one set of results to be compared. In FLOWPLOT, choose Files, Create, then open another flsgrf results file containing the other set of data using option 8 in PLTFSI or the Files, Open(Add) option in the Control Panel of FLOW-PLOT. This creates a combined plot file from which you can select members to be overlaid.
An alternative that is sometimes useful is to save the plots to be compared from one flsgrf results file to a temporary file. Then open the second results file and add to it the temporary file. This creates a smaller file to deal with. Of course, you could then select the plots to be compared in the combined file and save them to another temporary file. Continuing in this way it is possible to build up a file containing selected results from many separate flsgrf files.
A useful, but often overlooked feature in PLTFSI is the ability to specify the colors of individual plot lines. For example, you could set the line color for plot number 2 to red and plot number 3 to violet. To set plot attributes, enter option 10 (select plotting options), and then option 7 (select plot line attributes).<--mstheme-->作者: markchan 时间: 2005-7-15 18:21
flow_3d@126.com作者: markchan 时间: 2005-7-29 07:37
flow-3d 案例作者: markchan 时间: 2005-7-29 12:48
flow3d案例动画作者: markchan 时间: 2005-7-29 19:55
flow3d案例作者: markchan 时间: 2005-8-7 18:01
FLOW3D推广信息: 成君工作室----漳州培训分处9/1开始招生！！！
FLOW3D边界条件之Continuative
Use of the Continuative Mesh Boundary Condition
When there is a need to have fluid flow out one or more of the boundaries of a computational domain, the question arises: what is the right boundary condition? Several mesh boundary conditions can serve as outflow boundaries in FLOW-3D, including specified pressure, continuative and outflow.
The simplest and most commonly used outflow condition is the continuative boundary. A continuative boundary condition consists of zero normal derivatives at the boundary for all flow quantities. The zero-derivative condition is intended to represent a smooth continuation of the flow through the boundary. Therefore, using the continuative boundary condition is most suitable when the flow upstream from the boundary exhibits little variation in space (at least in the direction normal to the boundary) and time. This condition usually requires the continuative boundaries to be placed far downstream from any disturbances in the flow like constrictions or submerged bodies.
It must be stressed that the continuative boundary condition has little physical basis. Rather, it is a mathematical statement that may or may not provide the desired flow behavior. In particular, if flow is observed to enter the computational region across such a boundary, then the computations may be wrong because nothing has been specified about flow conditions existing outside the boundary. The entering flow is forced to do so from the condition of rest. This practice helps to reduce inflow and often results in a reasonable approximation of a smooth outflow condition.
Among other things, the zero-derivative condition at continuative boundaries implies that there is no acceleration or deceleration of the flow as it crosses the boundary. Therefore, the continuative boundary condition is not consistent with a significant non-zero force component normal to the boundary (for example, gravity).
The only input variable that can be defined at a continuative mesh boundary is fluid height, which can be used in free-surface type flows. However, its effect on the flow is quite limited since the flow near the boundary is not computed from the conservation equations, but rather set from the zero-derivative condition.
In short, a continuative boundary employs a very simple algorithm, but the results must be viewed with a good degree of suspicion. As a general rule, a more physically meaningful boundary condition, such as a specified pressure condition, should be used at outflow boundaries whenever possible.作者: wujianbei 时间: 2005-8-11 09:42
顶，我觉得不错哦，想学习学习作者: markchan 时间: 2005-8-12 08:26
实战案例
成君工作室出品13606906674
flow_3d@126.com作者: hzw-3 时间: 2005-8-12 15:32 谢谢作者: markchan 时间: 2005-8-13 08:57
TRUST ME,YOU CAN MAKE IT!!!作者: tkltkltkl 时间: 2005-8-21 17:28
mouldbbs.com的找来的充充数---FLOW3D船体设计作者: tkltkltkl 时间: 2005-8-21 17:29
FLOW3D船体设计2作者: tkltkltkl 时间: 2005-8-23 13:36
test作者: kfwkhh8 时间: 2005-8-27 14:56
支持一下。作者: markchan 时间: 2005-8-28 10:35
应用0作者: markchan 时间: 2005-8-28 10:36
应用1作者: markchan 时间: 2005-8-28 10:36
应用2作者: markchan 时间: 2005-8-28 10:37
应用3作者: markchan 时间: 2005-8-28 10:38
应用4
--谨供参考作者: markchan 时间: 2005-8-28 15:52
感受FLOW3D9.0作者: markchan 时间: 2005-8-28 15:55
感受FLOW3D9.0--物理求解界面作者: chbo 时间: 2005-8-28 16:33
培训怎样收费作者: markchan 时间: 2005-9-9 18:37
成君工作室flow_3d@126.com
压铸分析欢迎交流！
谢谢