How to make parameter option in turbulent model constants

Baejh · March 31, 2020, 06:05

Hi everyone!
I study about SST transition model coefficients effect on flat plate using sensitivity analysis.
So I have to simulate about 100 case changing coefficients.
For convenience, I want to set parameter about model coefficients.
In my fluent version(18.2), turbulent model coefficients can't make parameter setting like inlet condition(e.g. velocity magnitude).
Is there other fluent version to make parameter setting or other way to macro?

Thank you for reading my question

vinerm · March 31, 2020, 10:27

By model coefficients, are you referring to physical model, i.e., coefficients used by the turbulence model or do you mean some boundary or initial conditions for turbulence?

Both can be controlled via commands, however, where will you get 100 values for coefficients of the turbulence model?

Baejh · April 1, 2020, 07:34

Dear vinerm, Thank you for your response.

I mean turbulence closure coefficients like Ca1, Ca2 ,.. in SST transition model.
Make the about 100 cases changing the closure coefficients and get the result like skin friction(QOI) from each cases.
So I want to know how to change the model coefficients each case automatically(like macro).

vinerm · April 1, 2020, 08:42

Those can be changed easily using rpsetvar, however, do note that those are not meant to be changed drastically or without any logic.

Command to change an rp variable is

(rpsetvar '<variable name> new-value)

e.g., if you want to change Ca1 from 2 to 2.1, you may do it like

(rpsetvar 'trans-sst-ca1 2.1)

For variables that are enabled only with transition model, you have to use trans in front of their name, such as, in the example above. For those that are native to SST model, you can call those without trans, such as, $\beta_{i1}$ is called sst-beta-i1

Remember that parentheses are part of the command.

Baejh · April 2, 2020, 01:32

Thank you so much How to change the closure coefficient!
I will try to make a case for this way.

March 31, 2020, 06:05	How to make parameter option in turbulent model constants	#1
Baejh New Member Jae Hyeon Bae Join Date: Mar 2020 Posts: 4 Rep Power: 6	Hi everyone! I study about SST transition model coefficients effect on flat plate using sensitivity analysis. So I have to simulate about 100 case changing coefficients. For convenience, I want to set parameter about model coefficients. In my fluent version(18.2), turbulent model coefficients can't make parameter setting like inlet condition(e.g. velocity magnitude). Is there other fluent version to make parameter setting or other way to macro? Thank you for reading my question

March 31, 2020, 10:27	Model Coefficients	#2
vinerm Senior Member Vinerm Join Date: Jun 2009 Location: Nederland Posts: 2,946 Blog Entries: 1 Rep Power: 36	By model coefficients, are you referring to physical model, i.e., coefficients used by the turbulence model or do you mean some boundary or initial conditions for turbulence? Both can be controlled via commands, however, where will you get 100 values for coefficients of the turbulence model? __________________ Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.

April 1, 2020, 08:42	Model Coefficients	#4
vinerm Senior Member Vinerm Join Date: Jun 2009 Location: Nederland Posts: 2,946 Blog Entries: 1 Rep Power: 36	Those can be changed easily using rpsetvar, however, do note that those are not meant to be changed drastically or without any logic. Command to change an rp variable is (rpsetvar '<variable name> new-value) e.g., if you want to change Ca1 from 2 to 2.1, you may do it like (rpsetvar 'trans-sst-ca1 2.1) For variables that are enabled only with transition model, you have to use trans in front of their name, such as, in the example above. For those that are native to SST model, you can call those without trans, such as, $\beta_{i1}$ is called sst-beta-i1 Remember that parentheses are part of the command. Baejh likes this. __________________ Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.

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April 1, 2020, 07:34		#3
Baejh New Member Jae Hyeon Bae Join Date: Mar 2020 Posts: 4 Rep Power: 6	Dear vinerm, Thank you for your response. I mean turbulence closure coefficients like Ca1, Ca2 ,.. in SST transition model. Make the about 100 cases changing the closure coefficients and get the result like skin friction(QOI) from each cases. So I want to know how to change the model coefficients each case automatically(like macro).

April 2, 2020, 01:32		#5
Baejh New Member Jae Hyeon Bae Join Date: Mar 2020 Posts: 4 Rep Power: 6	Thank you so much How to change the closure coefficient! I will try to make a case for this way.