icepak教程-网格划分

MESHING
? 2006 ANSYS, Inc. All rights reserved.
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Chapter contents
Overview Global Mesh Controls Per Object Controls Priority Non conformal meshing Mesh Display Mesh Quality
? 2006 ANSYS, Inc. All rights reserved.
214
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Icepak automatic meshing: Overview
Mesh types in Icepak
? Hex Unstructured ? Hex Structured ? Hex Dominant ? Tetrahedral
Non-conformal Mesh
? Non conformal mesh at the boundaries of separately meshed assemblies (SM assemblies)
? Different mesh types can be used in SM assemblies ? Nesting of SM assemblies allowed
Meshing priorities
? Meshing priorities determine the ownership of a common region when different objects intersect.
Meshing is the most critical aspect of CFD modeling. A good mesh is absolutely essential for a good solution
? 2006 ANSYS, Inc. All rights reserved.
215
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Icepak automatic meshing: Overview
? Available meshers:
? Two Hexahedral meshers
-Unstructured - It can be used for most applications satisfactorily ? Mesh will follow geometry ? Uses all element types to fit the mesh to the geometry ? Background mesh is made of hexahedral elements
-Cartesian – Can be used if the meshed region consists of cartesian geometry ? Structured mesh consisting only of hexahedral elements ? Stair-step approximations to non-rectangular geometry
?Hexahedral mesh can be controlled by global, per-object settings and max grid size in SM assemblies.
? Hex Dominant mesher (HDM)
?Mesh will follow geometry ? Used for meshing CAD blocks, non-uniform polygons, ellipsoids, elliptical cylinders
?Hex Dominant mesh can be mainly controlled by max grid size in SM assemblies.
? Tetra mesher
? Used for meshing ellipsoids, elliptical cylinders, or polygonal ducting (use only if other meshers fails) ? When many objects have small dimensions (such as thin plates), the tetrahedral mesher may lead to very large meshes
? 2006 ANSYS, Inc. All rights reserved.
216
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Meshing: Meshing assemblies separately
? Mesh in Separately Meshed (SM) assemblies can be isolated from the outer mesh ? Hexa (unstructured and structured), Hex Dominant and tetra mesh can all be mixed
Select default Mesh Type
Toggle on Mesh assemblies separately and Allow different subgrid types
? 2006 ANSYS, Inc. All rights reserved.
217
Toggle on Mesh separately, slack values should be defined Select the Mesh type for sub-region
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Icepak meshing: Mixed meshing example
Missile
Tetra mesh
Board
Tetra mesh (overall model )
Hexa
? 2006 ANSYS, Inc. All rights reserved.
Hexa mesh (SM assembly)
218
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Guidelines to generating a mesh
Generate First Cut Mesh Course default options,
no settings for Max X,Y,Z
Examine the Mesh
Number of elements on flow boundaries such as vents - at least 4-5
Number of elements on solid faces
Number of elements between objects e.g.: heat sink fins need at least 3
Examine mesh using surface plots and cut planes
Always check quality using diagnostic
Refine the Mesh
Generate new Mesh
Re-examine
No
the Mesh
OK?
Yes
Solve
Refine mesh in regions of high velocity and thermal gradients
Low mesh count across an object - use x,y,z count Low and High element size/ratio to refine around objects
Inward height/ratio to refine within an object Outward height to refine mesh away from planar objects
Background mesh - set Max X, Y, Z sizes Use fluid blocks to refine the mesh locally
? 2006 ANSYS, Inc. All rights reserved.
219
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Elements of an Icepak mesh
Hexa structured mesh in Separately Meshed (SM) assembly
? 2006 ANSYS, Inc. All rights reserved.
220
Hollow block no mesh
‘O’ mesh
‘O’ grid height
Background mesh (hexa unstructured) Hex dominant mesh for Non-uniform polyblock (SM assembly)
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Global settings
Global meshing panel for Hexahedral and Hex Dominant mesher
Panels to generate, Display, Check quality, and Export
Global Settings - mesh type, maximum cell size etc.
Global Settings - for refining mesh
? 2006 ANSYS, Inc. All rights reserved.
221
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Global settings
? Mesh Type z Hexa-Unstructured z Hexa-Cartesian z Hex Dominant z Tetrahedral
? Mesh Units z Apply to all mesh control parameters with length unit z O-grid height is an exception (always in meter)
? Object Parameters z Mesh control parameters on individual object (Hexahedral mesher only)
? Mesh control parameters z Max X, Max Y, Max Z - Control the largest cell size in X, Y and Z direction z Init height - Maximum height of first cell away from surface of all objects within the model
? Minimum gap (Separation) z Tolerance used to remove small gaps/misalignments during meshing in each direction z Accept “change value” check: Toggle on to avoid any minimum gap related warnings
? Mesh default settings z Normal mesh - Provides an acceptable mesh for most situations z Coarse mesh - Provides a “first cut” coarse mesh that can be refined locally
? 2006 ANSYS, Inc. All rights reserved.
222
ANSYS, Inc. Proprietary

Global settings
Introductory Icepak Notes V 4.4
z Min elements in gaps - Minimum number of cells to be placed in fluid gaps
Min elements in fluid gap = 2
Min elements in fluid gap = 3
z Min elements on solid edge - Minimum number of cells to be placed on the edge of an object z Max O-grid height - Maximum height of the O-grid region from the surface of an object z Maximum Size Ratio - Controls the growth rate of cell size
Fluid Region
Δx1
Δx2
Solid region
Δx3
? 2006 ANSYS, Inc. All rights reserved.
O-grid height
Size ratio Δxi+1/ Δxi
223
ANSYS, Inc. Proprietary

Global settings
Introductory Icepak Notes V 4.4
z Min elements on cylinder face – number of elements on a quarter of a circle z Min elements on triangle face – number of elements on inclined surface of a wedge type of
geometry z Cylinder shrink factor – adjust the radius of cylindrical object in case of geometry singularity z Max elements – total number of elements allowed
? Additional Optional Flags z No “O” grid - Prevents “O” meshing on all objects z No group “O” grid - Does not group adjacent objects for “O” meshing, each object still have separate “O” mesh z Mesh assemblies separately - When an assembly has the option to be meshed separately, a localized (non-conformal) mesh will be created that is usually different from the mesh outside of the assembly z Allow different subgrid types- Available if non-conformally meshed assemblies exist and mixing mesh types is desired for different sub regions of the model z Add intersection curves- Related only to tetra mesher when geometries intersect with each other
? 2006 ANSYS, Inc. All rights reserved.
224
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Recommendations
? Max X, Y, Z z By default this is 1/20th of the cabinet dimensions z 1/10th of the domain size is sufficient for a coarse grid z Values smaller than 1/20th domain size is rarely needed and is not recommended z These are not meant to be used to refine the mesh close to objects, but purely to generate a reasonable background mesh
? Init Height z Recommended that you do not set this on large models as it can result in very large mesh counts
? Separation (Minimum gap) z Length of a cell edge will be greater than this value z It is recommended that you set this to 10% of the smallest dimension in your model for typical calculations to prevent any large volume changes occurring that might lead to inaccuracies in the results
? 2006 ANSYS, Inc. All rights reserved.
225
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Recommendations
? Min elements in fluid gap z Either 2 or 3 z More than 4 may refine the mesh in unwanted regions ? Use Object parameters instead
? Min elements on Solid edge z No more than 2 ? Use Object parameters instead if more are needed locally
? Max Size ratio z Between 2 and 10 ? Finer than 2 can over-refine the mesh ? User Object parameters to locally enforce finer growth around objects if needed
? Max “O” grid height z Default setting of 0 means that there is no control of the height of the cut-out region – usually does not need to be changed z Recommended to set a reasonable “O”-grid height ? Very much model dependant
? 2006 ANSYS, Inc. All rights reserved.
226
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Per-object controls (Hexahedral mesher only)
? User can reach per-object parameters for an individual object using either of the two methods:
z Use Global Mesh Control window and Toggle on Object Parameters, then select the object in perobject meshing parameters window
z Select the object in model tree and click on right mouse and use Edit Mesh Parameters option to open up Per-Object Parameters window
? 2006 ANSYS, Inc. All rights reserved.
227
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Per-object parameters
Select the objects from the Tree either one or many. Once selected they will be highlighted in the tree
Click on “Use perobject parameters”
Click to activate the option and set the requested value for that
option
If a mesh has been calculated - the current value will be shown for each of the parameters
you can set
? 2006 ANSYS, Inc. All rights reserved.
228
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Per-object parameters: Rectangular geometry
? Rectangular Prism shapes - e.g.: Block/Resistance z X,Y,Z count z Low/High X,Y,Z height ? Initial height - height of first cell outside the surface of the object z Low/High X,Y,Z ratio ? Growth ratio outside the object z Inward height/ratio ? Height/growth ratio of cells into an object measured from the object surface
? 2006 ANSYS, Inc. All rights reserved.
229
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Per-object parameters: Rectangular geometry
? Rectangular planar shapes - e.g. Rectangular vent, PCB, Plate etc... z X&Y, Y&Z, X&Z count z Low/High end height ? Height of first cell on either side of planar object z Low/High end ratio ? growth rate on either side of object z Inward height/ratio ? Height/growth of cells into the object
? 2006 ANSYS, Inc. All rights reserved.
230
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Per-object parameters: Circular geometry
? Circular planar objects - e.g. fan, circular planar resistance etc… z Additional settings are: ? Diameter count ? Number of cells across the diameter ? Low/High End heights and ratios ? Outward height/ratio ? Height and aspect ratio control away from the object
? 2006 ANSYS, Inc. All rights reserved.
231
ANSYS, Inc. Proprietary

Introductory Icepak Notes V 4.4
Per-object parameters: Other shapes
?Polygonal shapes ? Analogous to prism blocks/plates ? 3 controls: ? side counts – number of cells in that direction, side “n” = from vertex “n” to
vertex “n+1” ? Side heights – first cell height outside the specific side ? Side ratio – growth ratio on the specific side
4
Side 3, between node 3 and node 4
5
3
1
? 2006 ANSYS, Inc. All rights reserved.
2
232
ANSYS, Inc. Proprietary

ICEMCFD网格划分入门基础

WorkBench ICEM CFD 网格划分入门 111AnsysWB里集成了一个非常重要的工具：ICEM CFD。 它是一个建模、划分网格的集成工具，功能非常强大。我也只是蜻蜓点水的用了几次，感觉确实非常棒，以前遇到复杂的模型，用过几个划分网格的工具。但这是我觉得最方便和最具效率的。 网格划分很大程度上影响着后续的仿真分析——相信各位都有所体会。而ICEM CFD特别长于划分六面体网格，相信无论是结构或流体（当然铁别是流体），都会得益于它的威力。 ICEM CFD建模的能力不敢恭维，但划分网格确实有其独到之处。教程开始前，作一个简单的原理介绍，方面没有使用过ICEM CFD的朋友理解主要的任务： 111如下图： 1：白色的物体是我们需要划分网格的，但是它非常不规则。 2：这时候你一定想：怎么这个不规则呢，要是它是一个方方正正的形状多好（例如红色的那个形状）01 111于是有了这样一种思想： 1：对于异型，我们用一种规则形状去描述它。 2：或者说：如果目标形状非常复杂，我们就用很多规则的，简单的形状单元合成在一起，去描述它。 之后，将网格划分的设置，做到规则形状上。 最后，这些规则，通过最初的“描述”关系，自动的“映射”到原先的复杂形状上——问题就得到了解决！！！ ICEM CFD正是使用了这种思想。 如下是一个三通管，在ProE里做得

02 在ProE里面直接启动WB 进入WB后，选择如下图： 03 111如下： 1：代表工作空间里的实体 2：代表某实体的子实体，可以控制它们的开关状态3：控制显示的地方

04 下面需要创建一个Body实体 这个实体代表了真实的物体。这个真实的物体的外形由我们导入的外形来定义。 ——我们导入的外形并不是真实的实体。这个概念要清楚。 但是今后基本上不会对这个真实的实体作什么操作。这种处理方式主要是为工作空间内有多个物体的时候准备的。 05 1：点击“创建Body” 2、3：点选这两个点 4：于是创建出一个叫“Body”的实体 操作中，左键选择，中键确认，右键完成并退出——类似的操作方法很多地方用到，要多练习，今后

ICEM CFD教程

ICEM CFD教程 四面体网格 ?对于复杂外形，ICEM CFD Tetra具有如下优点： ?根据用户事先规定一些关键的点和曲线基于8叉树算法的网格生成，生成速度快，大约为1500 cells/second ?无需表面的三角形划分，直接生成体网格 ?四面体网格能够合并到混合网格中，并实施平滑操作 ?单独区域的粗化和细化 ?ICEM CFD的CAD(CATIA V4, UG, ProE, IGES, and ParaSolid, etc)接口，保留有CAD几何模型的参数化描述，网格可以在修改过的几何模型上重新生成 这是生成的燃烧室四面体网格，共有660万网格，生成时间约为50分钟 ?八叉树算法 Tetra网格生成是基于如下的空间划分算法：这种算法需要的区域保证必要的网格密度，但是为了快速计算尽量采用大的单元。 1.在几何模型的曲线和表面上规定网格尺寸 2.构造一个初始单元来包围整个几何模型 3.单元被不断细分来达到最大网格尺寸（每个维的尺寸按照1/2分割，对于三维就是 1/8）

4.均一化网格来消除悬挂网格现象 5.构造出最初的最大尺寸单元网格来包围整个模型 6.节点调整以匹配几何模型形状 7.剔除材料外的单元 8.进一步细分单元以满足规定的网格尺寸要求 9.通过节点的合并、移动、交换和删除进行网格平滑，节点大小位于最大和最 小网格尺寸之间

? 非结构化网格的一般步骤 1. 输入几何或者网格 所有几何实体，包括曲线、表面和点都放在part 中。通过part 用户可以迅速打开/关掉所有实体，用不同颜色区分，分配网格，应用不同的边界条件。几何被收录到通用几何文件.tin 中，.tin 文件可以被ANSYS ICEM CFD’s 所有模块 1.1输入几何体Import Geometry ? 第三方接口文件：ParaSolid 、STEP 、IGES 、DWG 、GEMS 、ACIS … ? 直接接口：Catia 、Unigraphics 、Pro/E 、SolidWorks 、I-deas… 几 何变化网格可以直接随之变化

ICEM 基础教程

第一章介绍 ICEM CFD 工程 Tutorials目录中每个工程是一个次级子目录。每个工程的目录下有下列子目录：import, parts, domains, mesh, 和transfer。他们分别代表： ? import/: 要导入到ICEMCFD中的集合模型交换文件，比如igs，STL等； ? parts/: CAD模型 ? domains/: 非结构六面体网格文件(hex.unstruct), 结构六面体网格分区文件(domain.n), 非结构四面体网格文件(cut_domain.1) ? mesh/: 边界条件文件(family_boco, boco)，结构网格的拓扑定义文件(family_topo, topo_mulcad_out), 和Tetin几何文件(tetin1). ? transfer/: 求解器输入文件(star.elem), 用于Mom3d.的分析数据 mesh目录中Tetin文件代表将要划分网格的几何体。包含B-spline曲面定义和曲线信息，以及分组定义 Replay 文件是六面体网格划分的分块的脚本 鼠标和键盘操作

第二章ICEM CFD Mesh Editor界面 The Mesh Editor, 创建修改网格的集成环境，包含三个窗口 ? The ICEM CFD 主窗口 ? 显示窗口 ? The ICEM CFD 消息窗口 主窗口 主窗口中除了图形显示区域，外，还有6个radio按钮：File, Geometry, Meshing, Edit Mesh and Output. The File Menu The File menu 包含 ? Open, Save, Save as, Close, Quit, Project dir, Tetin file, Domain file, B.C file, Import geo, Export geo, Options, Utilities, Scripting, Annotations, Import mesh, DDN part.

ANSYS ICEM CFD中文教程

ANSYS.ICEM-CFD中文教程 ICEM CFD 工程 Tutorials目录中每个工程是一个次级子目录。每个工程的目录下有下列子目录：import, parts, domains, mesh, 和transfer。他们分别代表： ? import/: 要导入到ICEMCFD中的集合模型交换文件，比如igs，STL等； ? parts/: CAD模型 ? domains/: 非结构六面体网格文件(hex.unstruct), 结构六面体网格分区文件(domain.n), 非结构四面体网格文件(cut_domain.1) ? mesh/: 边界条件文件(family_boco, boco)，结构网格的拓扑定义文件(family_topo, topo_mulcad_out), 和Tetin几何文件(tetin1). ? transfer/: 求解器输入文件(star.elem), 用于Mom3d.的分析数据 mesh目录中Tetin文件代表将要划分网格的几何体。包含B-spline曲面定义和曲线信息，以及分组定义 Replay 文件是六面体网格划分的分块的脚本 鼠标和键盘操作

第二章ICEM CFD Mesh Editor界面 The Mesh Editor, 创建修改网格的集成环境，包含三个窗口 ? The ICEM CFD 主窗口 ? 显示窗口 ? The ICEM CFD 消息窗口 主窗口 主窗口中除了图形显示区域，外，还有6个radio按钮：File, Geometry, Meshing, Edit Mesh and Output. The File Menu

ICEM CFD 基础教程

有redhong731@https://www.sodocs.net/doc/b718734872.html,提供版权所有,如有雷同…. 第一章介绍 ICEM CFD 工程 Tutorials目录中每个工程是一个次级子目录。每个工程的目录下有下列子目录：import, parts, domains, mesh, 和transfer。他们分别代表： ? import/: 要导入到ICEMCFD中的集合模型交换文件，比如igs，STL等； ? parts/: CAD模型 ? domains/: 非结构六面体网格文件(hex.unstruct), 结构六面体网格分区文件(domain.n), 非结构四面体网格文件(cut_domain.1) ? mesh/: 边界条件文件(family_boco, boco)，结构网格的拓扑定义文件(family_topo, topo_mulcad_out), 和Tetin几何文件(tetin1). ? transfer/: 求解器输入文件(star.elem), 用于Mom3d.的分析数据 mesh目录中Tetin文件代表将要划分网格的几何体。包含B-spline曲面定义和曲线信息，以及分组定义 Replay 文件是六面体网格划分的分块的脚本 鼠标和键盘操作

第二章ICEM CFD Mesh Editor界面 The Mesh Editor, 创建修改网格的集成环境，包含三个窗口 ? The ICEM CFD 主窗口 ? 显示窗口 ? The ICEM CFD 消息窗口 主窗口 主窗口中除了图形显示区域，外，还有6个radio按钮：File, Geometry, Meshing, Edit Mesh and Output. The File Menu The File menu 包含

ANSYS ICEM CFD 网格划分教程1

AutoHexa Tutorial Manual Version 4.2 March 2002

ii ? 2002 by ICEM CFD Engineering All Rights Reserved. No part of this document may be reproduced or used in any form otherwise without express permission from ICEM CFD Engineering. All other products or name brands are trademarks of their respective holders. ICEM CFD Engineering 2855 Telegraph Avenue Suite 501 Berkeley, CA 94705 https://www.sodocs.net/doc/b718734872.html, info@https://www.sodocs.net/doc/b718734872.html,

iii Version 4.2AutoHexa Tutorial Manual ICEM CFD Engineering Table of Contents Getting Started xi Tutorial Example 1.1: Modeling and Meshing a Room 1 1.1.1:Starting the Project (2) 1.1.2:Menus and Windows (3) 1.1.3:Creating Objects (4) 1.1.4:Mesh Generation (15) Tutorial Example 1.2: Modeling and Meshing a Subway Station 23 1.2.1:Starting the Project (24) 1.2.2:Creating Objects (24) 1.2.3:Copying Objects (27) 1.2.4:Creating Objects (28) 1.2.5:Creating Groups of Objects (30) 1.2.6:Creating Polygons (32) 1.2.7:Creating Quads (35) 1.2.8:Mesh Generation (38) Tutorial Example 1.3: Modeling and Meshing a Chemical Vapor Deposition Reactor 43 1.3.1:Starting the Project (44) 1.3.2:Model Creation (44) 1.3.3:Copying Objects (47) 1.3.4:Creating Objects (49) 1.3.5:Mesh Generation (52) Tutorial Example 1.4: Modeling and Meshing a Lab 57 1.4.1:Starting the Project (58) 1.4.2:Creating Objects (59)