Meshing software comparison
·
Tgrid (now named Fluent meshing)
·
Ansys meshing
·
ICEM CFD
·
Pointwise
·
GAMBIT
·
Hypermesh
·
Gridpro
·
Turbogrid
Top down method
- ICEM CFD, Gridpro
Bottom up
- Pointwise
ANSYS Meshing
Combines and builds on strengths of preprocessing offerings
from ANSYS: ICEM CFD, TGRID (Fluent Meshing), CFX-Mesh,
Gambit
a general purpose meshing tool that leverages the libraries
from the more advanced ANSYS meshing modules, delivering an easy to
use and parametric meshing solution. The tool works with fully
associative CAD geometry, allowing for automatic updates and easy to use
parametric studies.
The mesh types supported are:
·
Tetrahedral
·
Hexahedral
·
Prismatic
inflation layer
·
Hexahedral
inflation layer
·
Hexahedral
core
·
Body
fitted Cartesian
·
Cut
cell Cartesian
For detail of ansys meshing, see file
“ansys meshing”
Fluent Meshing
Fluent meshing is based on Tgrid,
What is it used for?
large and complex
geometries.
aerospace and automotive
area
HVAC, Oil & Gas,
Biomedical or underhood thermal
management where
• Starting point is
faceted/STL geometry or CAD
• Geometry can be
“dirty” with disconnected surfaces,
·
Overlapping geometry,
surface intersections, holes etc.
Fluent Meshing can
create very high quality, large cell count,
hybrid volume meshes for external aerodynamics.
create a high quality surface mesh externally
and use
Fluent Meshing for volume mesh growth
Problem:
Extracting the fluid
volume from solid CAD entities using a Boolean tool at the geometry level is a
great strategy for simpler geometries but can become extremely troublesome when
the number of parts in an assembly increases and gaps or holes (geometry
imperfections) exist.
Advantages:
First, Fluent meshing
gives me tools to automatically find and fix problems in assemblies (gaps
between surfaces, holes, etc). This speeds up considerably what was previously
a very manual process.
Second, once all of
these geometric problems are resolved, I can use a wrapper tool to extract the
fluid volume. It has excellent surface wrapping technology.
TGrid
Unstructured mesh
complex and very large surface meshes
ANSYS TGrid offers advanced prism
layer creation tools including collision detection and sharp corner
handling. ANSYS TGrid is also equipped with an advanced wrapping
procedure that produces a high-quality, size function driven connected
triangular surface mesh from a large set of unconnected faceted surfaces.
Surface and volume meshes may be imported into TGrid from GAMBIT,
ANSYS structural mechanics solutions, CATIA®, I-DEAS®, NASTRAN®, PATRAN®,
Pro/ENGINEER®, Hypermesh® and more. Extensive tools are included in TGrid
for improving imported surface mesh quality and for rapidly assembling meshes from
multiple parts.
TGrid's convenient mesh quality diagnostic tools allow for easy
verification of mesh size and quality.
ANSYS TurboGrid
bladed geometries, rotating machinery
high-quality hexahedral meshes
Geometry: blade design software, i.e. ANSYS BladeModeler
In a modern graphical user interface, selected topologies
are adjusted to the specifics of a particular blade design. The
integrated grid topologies ensure that an optimal mesh can be created, with
minimal user input required. The same topology is then automatically
adapted to variants of a design, ensuring that the mesh produced is consistent.
Such self-consistent meshes are critical when assessing differences in
performance predictions between designs to minimize the mesh dependency in any
such comparisons.
ANSYS TurboGrid includes full scripting for batch mode operation
to maximize productivity when assessing many variants to optimize blade
geometries.
ANSYS ICEM CFD
ANSYS ICEM CFD meshing software starts with advanced CAD/geometry
readers and repair tools to allow the user to quickly progress to a variety of
geometry-tolerant meshers and produce high-quality volume or surface meshes
with minimal effort. Advanced mesh diagnostics, interactive and automated
mesh editing, output to a wide variety of computational fluid dynamics (CFD)
and finite element analysis (FEA) solvers and multiphysics post-processing
tools make ANSYS ICEM CFD a complete meshing solution. ANSYS endeavors to
provide a variety of flexible tools that can take the model from any geometry
to any solver in one modern and fully scriptable environment.
·
Mesh
from dirty CAD and/or faceted geometry such as STL
·
Efficiently
mesh large, complex models
·
Hexa
mesh (structured or unstructured) with advanced control
·
Extended
mesh diagnostics and advanced interactive mesh editing
·
Output
to a wide variety of CFD and FEA solvers as well as neutral formats
Ansys Meshing Vs ICEM
ICEM CFD offers better control for creating the mesh and then
better diagnostics and mesh editing (automatic and interactive), so you can
probably get a better quality mesh... It just takes some experience and maybe
some effort.
But...
ANSYS Meshing is more automated and the mesh it generates passes
the checks (also done automatically in the background), so you don't need to
worry about it. In other words, it doesn't make much difference to the solver
if the quality is 0.45 or 0.55, but what should matter to you is how much
effort it took you to get that mesh. (I am assuming similar mesh type and
topology, which do make a difference, and I am assuming we are not talking
about poor elements (<0.1) in the areas of interest).
If ANSYS Meshing is giving you a decent mesh without too much
effort (you are happy) and the solver doesn't seem to mind, then just stick
with it and don't worry about doubling your effort to get 10% better quality.
ICEM VS pointwise
1. 非结构网格上，处理复杂外形，ICEM比Pointwise有优势，但是自从PW18出来后，这种优势已经很小了；
2. ICEM搞网格之前要修改几何，麻烦；Pointwise基本不用改几何;
3. ICEM生成混合网格比Pointwise鲁棒，复杂外形Pointwise有时候生成棱柱网格易出问题；
4. ICEM用的那套鲁棒的叉树算法消耗时间远高于Pointwise，经常八个核齐开生成个三、四百万网格就得用半个小时，Pointwise一般一个核几分钟就搞定（当然，它没多核版本）；这抵消了ICEM在复杂外形上的优势，生成网格经常要调整密度，调个三四次一天就过去了；
5. 目前中等复杂程度及简单的外形，非结构混合网格生成我倾向Pointwise，极复杂外形优先用ICEM；
6. 18之前的Pointwise不能加源项控制某一部分网格的密度，现在可以了，但是只能控制三维的，三维网格BLOCK的边界DOMAIN不能跟着内场网格同时加密，很傻逼；不知道什么时候能改好；
7. 18之后引入的非结构的各向异性四边形、六面体网格的生成很让人感兴趣，但是实在不鲁棒，一遇到复杂外形就乱七八糟。不知道什么时候能改到鲁棒好用。
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