Flow Science 於 2006 年 2 月正式發行 FLOW-3D V9.1 ,以下是 V9.1 主要新增功能說明:

I. Solver

New Split Lagrangian VOF advection model .
此新模型可以強化追蹤擴散的流體界面

A new VOF advection model has been added to track sharp and diffuse fluid interfaces. Compared to other VOF methods in FLOW-3D , the new method has superior accuracy in tracking sharp fluid interfaces and in conserving fluid volume. It is applicable to one and two-fluid, sharp and diffuse interface problems, but tracking sharp interfaces is where its real strength lies. This new model was featured in an article in the FLOW-3D Newsletter .
Additions to General Moving Objects Model.
移動物件模型 (GMO) 中新增熱傳遞及質量源的計算功能

Simulation of a sloshing tank using the new Split Lagrangian VOF method
Components defined as general moving objects (GMOs) will now be able to have the same heat transfer and mass source capabilities as non-moving components. These changes were featured in an article in the FLOW-3D Newsletter . Other additions to the GMO model include the ability to attach a moving history probe to a GMO component and the ability of marker and mass particles to stick to the surface of a moving object.
New Electric Conductivity model.
新增漏流介電質 (leaky dielectric) 材料計算模型

An extended “leaky dielectric” model has been added to the code. It works in conjunction with the electric potential, electric charge and dielectric models, and requires a positive electrical conductivity of the fluid. Electrical charge is generated at free surfaces and walls due to the differences in dielectric properties of the fluid, void and solid components. The existence of the charge changes the electric field and results in additional forces on the fluid. This new model was covered in an article in the FLOW-3D Newsletter .

GMO enhancements-- 'Sticky' particles adhering to moving sphere

Additions to Air Entrainment model
紊流模型不再需要使用空氣滲入 (air entrainment model) 。 自由液面氣泡產生模型增加入空氣回釋率計算。

Several important enhancements have been made to this model:
A turbulence model is no longer required to use the air entrainment model. Also, the entrained air is now allowed to escape back into the atmosphere. Finally, air entrained from or released into a confined adiabatic bubble will appropriately influence the pressure and volume of the bubble.
The model for the escape of rising gas bubbles at free surfaces, which is a part of the drift-flux model, has been improved to include a rate for their escape. This, in particular, improves the air entrainment model, where both the entrainment and escape of air occur at the free surface, and the resulting air concentration is determined by the rates of these processes.
  These changes were featured in an article in the FLOW-3D Newsletter .
Additions to two-fluid phase change model .
雙流體模型增加模擬純氣體的冷凝及純液體的蒸發現象,也更加入壁面上沸騰現象的模擬。

The two-fluid (liquid and compressible gas) evaporation/condensation model has been extended to allow condensation in pure gas and evaporation in pure liquid for both sharp and diffuse interface cases, and to enable preferential vapor nucleation (boiling) at walls.

New electric conductivity model used to simulate stream focusing

Two-fluid interface slip .
此功能可改善以往兩種密度相差非常大的流體間接觸面的流動性質計算的精度與穩定性。
When the two-fluid, sharp interface model is used, and the ratio of the densities of the two fluids is large (fluid #1 is heavier than fluid #2, like water and air), then velocities of the fluids at the interface can differ significantly. The newly-added interface slip model takes this into account improving accuracy and stability of the flow solution.
New “Cavitation potential” model .
此新模型專門用於預測壓鑄製程中,模腔受液態金屬流動侵蝕的情況。
This new model is designed to predict die erosion due to cavitation during filling in high pressure die casting. Metal pressure can drop several atmospheres below the metal vapor pressure in areas of very fast flow, possibly causing cavitation and erosion.
Surface tension model enhancement
.
新增的 Split Lagrangian VOF 方法可增強自由液面的表面張力模式的計算精度。

The accuracy of free surface curvature evaluation has been improved by including more fluid cells in the calculation. Additional improvements in free surface normal evaluation result in reduced noise in surface tension pressure. These enhancements, combined with the Split Lagrangian VOF method, improve the accuracy of the surface tension model in general.
Heat transfer solver improvement .
對於隱性及顯性的熱傳解已經做過最佳化的控制,因此收斂速度可以倍增。
The speed of the implicit solver for the heat transfer model has been increased by up to a factor of two. Convergence has also been improved. The explicit solver for the thermal conduction in fluids has also been optimized for speed.

The bottle filling example above shows how the new features of the air entrainment model can be used to model bulking in fluids due to air entrainment.

 


II. POST-PROCESSING
增加許多改善後處理結果顯示效率的措施,例如增強了加了 STL 物件及其 3-D 網格的顯示功能。對於向量圖及流線圖也可以 3-D 圖顯示等高面。
Numerous enhancements have been implemented for both improving display options and for improving rendering speed and efficiency. For example, the mesh used to create a simulation will be able to be displayed in 3-D plots, users will be able to apply transparency individually to each STL object imported into the Display window, vectors and streamlines can be displayed together with isosurfaces in 3-D plots, and dynamic memory allocation has been fully implemented in the post-processor to improve post-processing efficiency in terms of memory use and speed and remove limitations on the size of the results file.

III. GRAPHICAL USER INTERFACE (GUI)
以全新的 V9.0 的人機介面為基礎, V9.1 人機介面更大步躍進。
The redesigned GUI introduced with Version 9.0 has undergone further advances for Version 9.1. For example, rubber-band mesh creation has been added for cylindrical coordinate; features have been added to enable users to copy, move split and slice mesh blocks; icons for many frequently-used GUI functions have been added to Meshing & Geometry and Display tool bars for faster setup; and subcomponents that are defined as a complement are automatically shown in a semi-transparent mode to reveal any geometric features inside. Even though some variables must still be defined directly in the prepin file using the Text Editor , access to input variables and models has been expanded in the model builder.

IIII. Support 64-bit Windows

V9.1 已經可以支援 AMD Opteron 及 Intel Xeon 等 X86 64 位元 CPU 於 64 位元 Windows 及 RedHat Enterprise 3.0 等作業系統上之運算。使用者可以建立的模擬模型大小遠遠超過 32 位元的限制,在 64 位元中的FLOW-3D V9.1 ,使用者的模擬分析將僅受到安裝於電腦中記憶體容量大小的限制,例如具有 4GB 記憶體可以模擬最多接近 1 千萬網格的模型。
Flow Science's latest release of FLOW-3D -- Version 9.1 -- adds support for 64-bit Windows and RedHat Enterprise 3.0 for the x86 64-bit processors in AMD's Opteron and Intel's Xeon workstations. In addition, Version 9.1 also supports Windows XP Pro IA64 and Windows Server 2003 IA64 for the Intel Itanium 2 workstation. Moreover, for the first time, FLOW-3D can run in shared-memory parallel mode on 32-bit Linux processors and 64-bit processors running either Windows or Linux.
With 64-bit support, users will be able to build large simulations exceeding the traditional limits of 32-bit memory. Users' simulations will be limited only by the amount of installed memory on their computers. For example, with 4 GB of installed memory, a user could run a simulation with up to 10 million cells (depending on the number of physical models activated).

The new two-fluid interface slip boundary condition allows the velocities fields in the two fluids to be decoupled




New cavitation potential model enables casting users to predict potential for die erosion due to cavitation





New post-processing options include vector and streamline displays


相關課程連結:
FLOW-3D (CFD 流體動力分析 )
FLOW-3D (鑄造模流分析應用)
最新課程連結:
3C 電子散熱設計與分析
塑膠模具設計實務
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