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-   -   Ramping Courant Number (http://www.cfd-online.com/Forums/star-ccm/87541-ramping-courant-number.html)

screech1987 April 22, 2011 12:49

Ramping Courant Number
 
A quick query about the 'ramping' of values in StarCCM+.
As I am running a highly hypersonic case the starting Courant number had to be small, but I have put a rampping function in to gradually increase the value over a number of iterations.
The set up in Star is straight forwards with a start and end iteration, and a initial Courant number defined. But what I could not gather from the UG was a what value does the Courant number reach or plateau out at, or is this just dependednt on the solution and applies the maximum value it can?

Cheers,
Martin

f-w April 22, 2011 13:59

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screech1987 April 23, 2011 08:06

Cheers! I did wonder about that.

rwryne April 25, 2011 11:06

Quote:

Originally Posted by screech1987 (Post 304787)
Cheers! I did wonder about that.

It is a bit cryptic, the way they have the final number seperated from the initial number.

abdul099 April 28, 2011 17:38

Not necessarily cryptic. The ramp just has its own definition.
Imagine, you want to change the CFL number much after the end of the ramp. Why should you search for the CFL number by looking in the ramp? There's no reason and some guy might complain about a cryptic way they have hidden the CFL number in the ramp node.

So to keep it seperate from the ramp (and its initial value) is just as much cryptic as it might be in another case when you have put it together.

rwryne April 29, 2011 09:54

Quote:

Originally Posted by abdul099 (Post 305500)
Not necessarily cryptic. The ramp just has its own definition.
Imagine, you want to change the CFL number much after the end of the ramp. Why should you search for the CFL number by looking in the ramp? There's no reason and some guy might complain about a cryptic way they have hidden the CFL number in the ramp node.

So to keep it seperate from the ramp (and its initial value) is just as much cryptic as it might be in another case when you have put it together.

I understand why they have it how they do, but still think it is a bit cryptic not to have the start value and end value next to eachother. Maybe the placement of the variable should be moved when ramp is turned on?

abdul099 May 1, 2011 06:22

That would be an option, but that would affect the Java API as well, so most likely that will not be changed.
An to be honest, it's no big issue as long as you know where you can find it, isn't it?

rwryne May 2, 2011 08:18

Quote:

Originally Posted by abdul099 (Post 305759)
That would be an option, but that would affect the Java API as well, so most likely that will not be changed.
An to be honest, it's no big issue as long as you know where you can find it, isn't it?


It is not an issue to me, but I think it does confuse people new to the software (which is why we have a thread here)


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