求教：与COMSOL结合在地学里最好用的三维CAD软件

zy-nwu

这里强调的地学三维模拟，主要是利用DEM地形数据（其实就是一大堆成曲面分布的xyz数据点）建立三维地形建立CAD，然后在此基础上利用comsol做风运动、降水、传热等模拟。这些天试了试GOCAD，GOCAD建模倒是很好，但不好导出到Comsol。Global mapper也容易形成曲面，但是与COMSOL没有接口。请教有经验的人告诉我一下，哪个CAD软件处理这些问题最好用（可以用xyz数据生成曲面或体）。
感谢！

edodo

我想你需要的可能是这方面的资料

http://www.comsol.com/support/knowledgebase/838/   Topological Data, GIS, Digital Elevation Models (DEM)Topological 2D elevation data can be imported and a moving mesh method (ALE) can be used to adjust a surface mesh to the elevation data. Ask your COMSOL representative for model id 4563 for an example. An alternative is to use the function geomsurf to create a geometry that fits the data.


另外，附件中的资料可能对你非常有帮助。
Bringing GIS data into COMSOL

kinggun

看这个图好象就是用的COMSOL自带的脚本几何建模函数。你可以查阅Scritpting Guide。

zy-nwu

看这个图好象就是用的COMSOL自带的脚本几何建模函数。你可以查阅Scritpting Guide。
kinggun 发表于 2010-7-27 17:57

谢谢Kinggun版主，上次你推荐的geomsurf我用过，数据少还行；但数据多了，地形复杂了，我的机器反应不过来，即使matlab搞定了，导入comsol时还是内存溢出。

如果有专门的软件干这个，就省事了。

不过Script Guide我现在的确没有好好看 兴许还有好办法。

zy-nwu

4# edodo

这个信息太有用了！但是现在我还没有实现，附件presentation文件中提到的“DEMREAD（infile）”命令我不知道在哪里？

非常感谢！

zy-nwu

需要License，谁能帮我下？
Dear ....,

Your support question has been assigned a case number: 427242.

In order to process this case, please provide your COMSOL license number,
you find it in Help > About COMSOL after opening the program.

To guarantee you the best service, we recommend that you always direct
your questions to support@comsol.com, and not directly to a support
engineer.

Best regards,
。。。。

zy-nwu

最后通过与一个老外的交流，我得到了想要的效果；是通过ALE方法实现造型的，真是有创意，贴出来，分享一下！（PS：老外的态度有时候真让人感动！）
The procedure to read a DEM file is the following:
First of all you need a .txt file (your DEM file) that must be formed by 3
coloumns with all the x,y, and z data (if is a 3D
model)
Then (if you are using a COMSOL 3.5 or 3.5a) you have to:
Click Option-->Functions
New (give a name for the function) for instance: dem
Choose Interpolation-->Use data from file
Browse your .txt file and click ok.
Then choose--> Interpolation method--> Linear
Extrapolation Method-->Costant
If the file is well read you should see the "dimension 3D" in the function
description area.
Then you have to recall the Moving Mesh ALE module from the model
navigator
Once you did it, go to make sure you are in this mode ( you can choose it from
the button "Multiphysics" in the graphical
interface) and go to Physics -->Subdomains Settings
Choose the domain on which you want to create the DEM (usually is the top of
your model) and in the area "rescribed
displacement" go to dz ( the third space) and insert an expression like this:
dem(X,Y)*(1+Z/3000)
3000 is an expample. Because default values are in meters it is 3 km and
corresponds to the maximum depth of the layer

you want to move. It is arbitrary and it depends on the dimension of your model
(namely it could be written in cm or mm
also).
The remaining domains should be setted in the "No displacement condition".
Finally mesh it all and execute the moving mesh in the solve manager area.
Inital value-->Select inital value expression
Solve for-->Select only moving mesh ale
Output -->leave so
Then click solve button.
In the post processing area -->;Plot parameters->Subdomain or Boundary setting
select z displacement to see the results.
I hope to have helped you.
Ps: If some of your tutors are interested I am opened for collaboration ( I work
principally with structural mechanichs and
partially with fluid dynamics) or I can do a seminar in your University if the
expenses for travel and living are paid.
感谢所有回帖者。