SCDM-Intro_Workshop04B_CFD_Geometry_from_Scratch

只显示曲线
一个重要的初始步骤为创建缺失的曲线, 建立连通的几何并诊断几何 Geometry -> Repair -> Build Topology 这可以看作是geometry 标签栏最重要的按钮, 所以我们应关注每一个细节.
2023/9/3
ICEM CFD/AI*Environment 5.0
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Building Topology 建立拓扑
创建复杂的模型是可以实现的, 我们只 对一些重要的功能作简略的概述 – 导入模型 – 建立拓扑结构 – 生成中面
采用ICECFD几何工具生成的带有反推 力装置的喷气发动机模型
2023/9/3
ICEM CFD/AI*Environment 5.0
2
几何操作
创建点
•从屏幕 •指定坐标 •平移 •中心点 •中间点 •端点 •交点 •沿曲线 •投影到曲线/曲面
ICEM CFD/AI*Environment 5.0
5
几何导入
使用 Geometry -> Import . . . CAD 文件 最初转换成 tetin (*.tin) 格式, 然后引入ICEMCFD/ AI*Environment
几何表现为一些为连接到一起的线和面, 即使是实体模型也将作为线和面导入.
在 Workbench 环境下, Design modeler 数据库可转换为 AI*Environment.
小平面数据格式: 将三角数据看作划分网格的几何 – Mesh Formats – STL – VRML
Pro/E 和UG 导入需要 Cad 库文件, 因此 CAD 软件 和注册必须能够使用时才能输入格式
– Catia V4 & V5
– UG

– 面网格可以单独保存
• 对不完整的几何体有容错能力
2023/10/21
ICEMCFD/AI*Environment 5.0
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特性: 六面体网格划分
• 强大的六面体网格生成能力 • 自顶向下或自底向上分块方法 • 复杂模型网格的快速生成 • 快速重复操作
– 弹性分块适合相似几何模型 – 对几何尺寸改变后的几何模型自动重划分网格
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模型树
• 设定窗口显示的图形 • 包含5个主要项目; Geometry几何, Mesh网格,
Properties属性, Parts部分 and Subsets子集 • 单击模型树分枝上的眼镜图标控制可见与否
– 红 X 图标表示 这一分枝(包含所有子分枝) 不显示
– 整个眼镜图标表示这一分枝下所有可显示项均可见
率
• Tri (STL-like):
– 生成三角面面网格 – 没有内部点
2023/10/21
ICEMCFD/AI*Environment 5.0
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特性: 混合网格
• 棱柱层
– 在四面体网格中提高边界层计算结果
• 六面体和四面体区域交界处采用棱锥体 网格
2023/10/21
ICEMCFD/AI*Environment 5.0
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视图操作
1 使用键盘: H – 主视图
Shift X - +X视图 Shift Y - +Y视图
Shift Z - +Z视图
2 单击视图中坐标图标
3 View > View Control
例如: 单击 Y 轴 使Y 轴 垂直屏幕
保存视图
2023/10/21
ICEMCFD/AI*EnvironmenEMCFD/AI*Environment 5.0

Example on using commercial software“ICEM CFD 5.1”Flow around a circular cylinderYTwo Dimensional problemsFlow around a circular cylinderProblem DescriptionAir flows across a cylinder with the uniform velocity in the wind tunnel. The length of the wind tunnel (fluid domain) has 25m long and 10 m height. The diameter of cylinder is 1m .Assumption and Boundary Conditions: 1. 2 dimensional problems 2. Steady state condition 3. The uniform flow velocity 4. No Heat transfer5. Neglect the gravitational force6. Constant air densityPre-processing stageIn this stage, we implement the “ICEM CFD” to perform the pre-processing work. The basic steps as follow:1. Establish geometry model2. Block the parts3. Generation the O grid4. Mesh the model and check quality of mesh5. Extrude the mesh6. R eset the BC’s (boundary conditions)7. Output toCreating Geometry1. Open ICEM CFDDouble Click the “ICEM CFD” Icon , afterwards, you can see the interface of the ICEM CFD.InletOutlet5DCylinderWall (SideB) Fluid domain5D20DWall (SideA)Open File>New Project…:2. Creating Geometry:A.PointsClick button “C reate Point ” and then click button “Explicit Coordinates ”Set the points in Cartesian coordinate system(X, Y, Z) with( X=0, Y=0, Z=0 ) respectively.Click “Apply” button and see the screen: a point is createdA tree widget can be seen at left of the screen (A) and (B)A BThe same method creates other points:X=-5; Y=5, -5X=20; Y=5, -5B.Draw line (curve)First of all see the tree widget, open Model>Geometry>Points by right buttonSelect Show Point Names and you can see the name ofeach point like the figure showed.Now you can create curvesClick button “Create/Modify Curve”Click button “Create Curve”Note: the left corner of the black screen: Select locationswith left button, middle=done, right=cancelSelect points by using left button of the mouse.Change the name of the Part with “INLET”:A BSelect and with left button (A),And draw a line with middle button “done”(B) and the INLET part is created in the tree widget.The same steps draw the curves named “OUTLET, SIDEA, SIDEB” with the 7and 8, and , POINTS.05 and respectively.We will see the line and the tree widgetDraw the cylinderClick button“Circle or arc from Center point and 2 points on plane ”.Set the Part with name “CYLINDER”Click button and select points “POINTS.00,POINTS.01, POINTS.03” with left button respectively(A).A BDraw the cylinder by middle button (B).See tree widget:Close Points name Use button to fit the window.Set the body and material.Click button “Create Body”Choose button “Mater ial Point”and select“Selected surfaces” in the “By Topology” menu.Change the name of the part with “FLUID”; open theShow Point Name of the tree widget and use selectand .The same way change the part name with “CYLINDER”and select and .Close Show Point Name and open the tree widget:Open the bodies and you can seeAt last, open the File>Geometry>Save Geometry As…Give it the name with “cylinder_2d”. Click “save”.Now we begin to block the model.Click button “Create Block”See the first one , choose the part with “FLUID”,from the pull down menu select “FLUID”And set the Initialize Blocks type with “2D Planar”Click “Apply” button.A BWe will see that the colors of figure are changed. From (A) to (B)See the tree widget: Model>BlockingThen create some assistant points with button “CreatePoint”{Y=0X=-0.45,-0.4,-0.35,-0.3,-0.25,-0.2,-0.15,-0.1,-0.5, 0.5,0.1, }{X=0}Now begin to block the regionClick button “Split Block”Then select button “Split Block”See the split method, select “Prescribed point”Use the put down menu to select the Prescribed point,Use the button firstly select the Edge “INLET” andsecondly select the Point “POINTS.03”.We will see the block line in the vertical direction of theINLET.Zoom the fiure.The same way we draw other block lines.From the to POINTS.04”See the tree widgetSelect the “Blocking” and select “Index Control”Model>Blocking: Index Control (using right button of the mouse) We can see at the right corner of the screenBy using button and we set I min=2 and see the figure The same way we set I max =3 , J min=2 , J max=3And the screen shown thatThe same way block again from to POINTS.44”:(A)(B)(C)A B CAfter block.See the tree widget: Model>Parts>VORFN :using the right button select “Add to Part”. Click button “Blocking Material”, Add Blocks to PartUsing select blocking regions and we can seeZoom the block regions (A).Select the blocks in the cylinder or attached the cylinder (B)(C).Using the middle button to set it OK , and you can see blow (D).Click button “Associate”ABD CSelect the associate edge to curve “Associate Edge toCurve”buttonUsing the choose the edge and curveChoosing edge:Select curves:Middle button:CBASet O gridClick button “Split Block”Click “Ogird Block”buttonSelect theSee the tree widget: Open Model>Parts>VORFNOpen the VORFN (A)AUsing button to selectin or attached the cylinder (B)(C)(D).B CD EUsing middle button to click “Apply”(E)Close “VORFN” from the tree widget (F)F GClick the “Reset”(G)Mesh the edgesClick button “Set Curve Mesh Size”Using button to select Curve(s):Choose Method with “Element count”Set the Number with 100 and click Apply.See the tree: close the Model>Geometry>points, and theModel>Blocking>edgesUsing right button to select Model>Geometry>Curves:Curve Node Spacing (by using right button)The same way set the “INLET” and “OUTLET” withnumber 100, the “SIDEA” and “SIDEB” with number 250.Click button “Pre-Mesh Params”Choose Blocking >Pre-Mesh ParamsClick button “Update Sizes” and keep default,Then click ApplySee tree open Model>Blocking>Pre_Mesh: Project faces(by using right button)And we will see a menuClick Yes.Now we will see the mesh of the model.Zoom it see the local partClose Geomery>Points and curves, and Blocking>Edges.Then open File>Mesh>Load from BlockingOpen File>Mesh>Save Mesh As…: and set the name with “cylinder_2d”Open File>Blocking>Save Blocking As…: Save block with the name “cylinder_2d”Check the quality of the meshClick button “Display Mesh Quality”Click ApplyWe can see no negatives mesh.Extrude meshClick button “Extrude Mesh”Use to select Elements:Method 1Click button “Select items in a part” and a menu appears:Click “All” and “Accept”Method 2A BPut the left button and drag it to select all the regions (A)(C). Click middle button to accept (B)Give the New volume part name “FLUID2D”, new side part name “SIDE”, new top par name “TOP”And set the Spacing type>spacing with ”, then ApplyCSo the mesh change a height in the Z direction (D)DBox ZoomE FClick button “Shaded Full Display”(E)(F) Check the quality of the extrude meshSee the tree widget:Close top “TOP” (B) Close “FLUID” (C)A BSet the new boundary conditionsSee the tree widget:Model>Parts: Create Part (by using the right button)Click “Create Part by Selection ” button From the pull down menu of the Part: select the “CYLINDER ” Using and left button drag the regionUsing middle button accepts it, so a new CYLINDER boundary condition has been set (C).CBACThe same way set the INLET, OUTLET, SIDEA and SIDEB boundary conditions. INLETThe Whole Boundary Conditions See the tree widget: CA BA Open Model>Parts>FLUID(B)B Open Model>Parts>TOP(C)CSix kinds of patterns Click File>Mesh>Save Mesh As… And save the new mesh with name “cylinder_2d_extrude”.Output the mesh file to CFXClick button “Select solver ” and choose “CFX-5” Click “Okay ”C B FE D AClick button “Write input”Keep default and click “Done”Then the Domain selection appearsKeep the Selected domains with “cylinder_2d_extrude.uns” and click “Done”.Now we will see the created files in working directions:From these files, we must note that only the file named “cfx5” can be inputted in to .1 The mesh is finished.Other examples:。

5梁
抽取
– 利用此工具把3D实体转换成梁，抽取完成后会自动生成横梁 轮廓
定向
显示
– 在显示线型横梁与实体横梁之间切换
A Pera Global Company © 2009 PERA China
小型表面
– 探测并去除小面以及长条面
相切
– 探测面与面之间近似相切的线，并调节面使其相切
A Pera Global Company © 2009 PERA China
2调整
简化
– 检查涉及，把复杂的面和曲线简化成平面、圆锥、圆柱、直线、 圆弧等。
A Pera Global Company © 2009 PERA China
ANSYS SCDM
第三章 模型修复与结构建模
A Pera Global Company © 2009 PERA China
Байду номын сангаас 1修复
间距
– 用于去除面面之间的小间隙
缺失的表面
– 可自动探测并填充目标对象上的缺失面
A Pera Global Company © 2009 PERA China
1修复
干涉
– 探测并去除不协调体之间的干涉
A Pera Global Company © 2009 PERA China
5梁
轮廓
创建梁
– 选择轮廓后，创建选项才会激活，然后可沿边或是一系列的点，或是选择两 点在两点之间创建梁。
A Pera Global Company © 2009 PERA China
3定义
点焊
– 在两个面之间创建点焊，每个焊点由两个点组成，分别位 于焊接的两个面上，没个点必须依附于线或面