FLOW-3D中国分公司/三维流动贸易(上海)有限公司

利用“弗劳德数”(Froude Number)作为铸造充填过程中质量评估的判断依据

作者:Carl Reilly,Supervisor: Dr. Mark Jolly,Co Supervisor: Prof Nick Green,The University of Birmingham Placeholder image

从以往的研究中,已经得知在浇铸系统控制较好条件下,铸件的质量可以进行控制。浇铸模型如图所示:

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不良的浇铸过程( X-Ray )

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良好的浇铸过程( X-Ray )

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氧化膜形成机理

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何谓弗劳德数( Froude Number )?

弗劳德数是流体质点加速度产生的作用力与重力形成的作用力的比值。

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Froude Number 弗劳德数可以用来判断流体的卷入气体程度。当 Froude Number > 1.7 时,流体就会卷气,当 Froude Number 在 4~12 之间时,流体会产生大量卷气。

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利用 FLOW-3D 的客制化功能,研究采用自行开发的子程序套入计算。

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分析后结果判定的重点

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FLOW-3D 分析的相关设定条件

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结果

运用统计分析的方式

ANOVA (Analysis of Variance)

  • Both in-gate and sump height shown to be significant
  • In-gate P-Value : 0.0001
  • Sump height P-Value : 0.0033
  • Best Result

  • Lowest sump and highest in-gate
  • Worst Result

  • Biggest sump and shortest in-gate
  • Interactions

  • Low level identified
  • 最佳设计-125mm Sump(Smallest Sump) and 100mm In-Gate(Largest)

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    最差设计-500mm Sump(Largest) and 25mm In-Gate(Smallest)

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    结论:

  • The design of a castings in-gate is of up most importance
  • Short in-gates increase the persistence of the return wave
  • The design of a sump is critical to its effectiveness
  • Incorrect designs can be extremely detrimental to casting integrity
  • Interaction is present between the sump and in-gate
  • system must be designed as a whole
  • 注:自 FLOW-3D V9.3 版之后, Froude Number 可在输出选项中选择输出(不需要再自行撰写客制化程序)

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