how to create cgrid.cgrd file
 

hi star-cd users

i cant do the tutorial 11 2-D FLOW AROUND TWO OBJECTS PASSING EACH OTHER.

in this tuto how to create cgrid.cgrd file. in tutorial they tell use star-cd editter other editter. i am using notepad. is it correct or not?? but i cant go afterwards. system tells " cant open the cgrid.cgrd file" please help me by kathir my e-mail id : kathiravan_memech@yahoo.co.in

Re: how to create cgrid.cgrd file
 

What is the version of star you use?

Re: how to create cgrid.cgrd file
 

my software version is 3.24. please tell what is the signifient of cgrd file

Re: how to create cgrid.cgrd file
 

cgrid.cgrd is called at each step to update the geometry. A moving geometry problem may be divided into two stages. (i) According to time, the grid connectivity is changed. (ii) cgrid.cgrd is then called to change the overall shape: once the grid connectivity is updated, the real positions of the nodes have to move as well.

In 3.15B, the moving mesh did not simply run at all. In 3.24, I have experienced a big issue in compiling the event file. The grid processing is piped on the screen. Thus, in case cgrid.cgrd is too long, the `y/n/c' prompt appears during the event file building, destroying all the step definitions. The only workaround I have found is to reduce the cgrid.cgrd file to make it shorter than the output window size. No message is accidentally prompted in the event file. Of course, if the case is too complex this workaround cannot be used.

Re: how to create cgrid.cgrd file
 

It's only a problem of the windows version. This type of calculation runs without problems since version 2.XX using Unix and later Linux.

Re: how to create cgrid.cgrd file
 

I am using linux

Re: how to create cgrid.cgrd file
 

starcd (tried on V3.22) has many similar issues. Same thing happens while entering table entries through macro. It can not take more than 92 entries. After that it simply ignores, without any intimation.

Re: how to create cgrid.cgrd file
 

hi,

i am using verson 3.22 on windows. i tried tut. 13 as per the instructions given in there. it gives me error msg 'can not read cgrid.cgrd file'. do i need to write moving grid commands first and then give command 'read,cgrid.cgrd'?? and if yes, where should i write them? in notepad?

i had the same problem with one other moving mesh tutorial.

Thank you for your help.

Re: how to create cgrid.cgrd file
 

It is a real shame that there are people around trying to do cfd works and don't even know how to use a simple text editor!

Re: how to create cgrid.cgrd file
 

hi William,

Yes you can say that as you must have been using star-cd for a while.. I have mentioned that I am trying tutorials as per the instructions given which means that I am a first time user.

I would appreciate if you can answer my stupid question instead of critisising that.

Re: how to create cgrid.cgrd file
 

I was simply talking about the ability of windows users to create a simple text-file using one of the several hundred editors available around. This is something one should learn during the first years at school and has nothing to do with starcd at all.

Yes, before you can read a commandfile into prostar you have to create it. You can do this using for instance notepad or the editor in prostar (file -> edit file).

Re: how to create cgrid.cgrd file
 

Hello William,

Thanks a lot for your proper reply.

Arpan