Max value in transient analysis

gbrajtm · June 15, 2017, 13:14

In a transient analysis, i have nearly 250-time steps. To find the maximum value of the output among all obtained results I have to put a chart and find the maximum value. But now I have a situation where I have to find the maximum value through another method.
Is there any alternative for this. I didn't find any solution in tutorial.

ghorrocks · June 15, 2017, 18:13

I would export the monitor points to a CSV file, then you can use matlab/python/excel/whatever to do more sophisticated analysis on the results.

gbrajtm · June 18, 2017, 11:56

I am doing a CFD optimisation, where force is the output.
My problem is in DOE. I wanted to know which time step force it is taking for particular design point. I want the maximum value of force in that table.

ghorrocks · June 18, 2017, 19:06

I don't understand your question. Also your second post appears to have nothing to do with your first post. You better explain what you are doing better.

gbrajtm · June 19, 2017, 01:09

I am Doing an optimisation using CFD results.
The output of the CFD is 'Force'. Since the analysis is transient there are 200-time steps. Each time step will have different force. This force I have assigned as the response parameter to optimisation (design of the experiment, DOE). As shown in the attachment the DOE will have a different analysis, for each analysis, it will calculate the force.
Now I wanted to know which timesteps force it is showing for the DOE. Presently I am getting negative values which are not correct, instead, i want maximum values in that table. If I could write some expression to find the max value for each analysis I can give that as the output parameter, which will solve my problem.

Светлана · July 19, 2017, 02:15

I'm sorry, I think CFD-Post does not have an expression for "maximum of this expression over time".

Go to CFX-Pre. Make it output the value of interest as a monitor.
In CFX-Solver, save the user point monitor plot as CSV file.
Do the post-processing using any tool such as GNU Octave, a spreadsheet, etc.

gbrajtm · July 19, 2017, 03:00

thanks, I will try out other alternatives.

Светлана · July 19, 2017, 03:05

OK, keep everyone updated please. :-)

June 15, 2017, 13:14	Max value in transient analysis	#1
gbrajtm Member Dr Gurubasavaraju Join Date: Dec 2014 Location: Bengaluru India Posts: 77 Rep Power: 11	In a transient analysis, i have nearly 250-time steps. To find the maximum value of the output among all obtained results I have to put a chart and find the maximum value. But now I have a situation where I have to find the maximum value through another method. Is there any alternative for this. I didn't find any solution in tutorial. Светлана likes this.

June 15, 2017, 18:13		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	I would export the monitor points to a CSV file, then you can use matlab/python/excel/whatever to do more sophisticated analysis on the results. Светлана likes this.

June 18, 2017, 19:06		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	I don't understand your question. Also your second post appears to have nothing to do with your first post. You better explain what you are doing better. Светлана likes this.

June 19, 2017, 01:09		#5
gbrajtm Member Dr Gurubasavaraju Join Date: Dec 2014 Location: Bengaluru India Posts: 77 Rep Power: 11	I am Doing an optimisation using CFD results. The output of the CFD is 'Force'. Since the analysis is transient there are 200-time steps. Each time step will have different force. This force I have assigned as the response parameter to optimisation (design of the experiment, DOE). As shown in the attachment the DOE will have a different analysis, for each analysis, it will calculate the force. Now I wanted to know which timesteps force it is showing for the DOE. Presently I am getting negative values which are not correct, instead, i want maximum values in that table. If I could write some expression to find the max value for each analysis I can give that as the output parameter, which will solve my problem. Светлана likes this.

July 19, 2017, 02:15	Write it from CFX-solver	#6
Светлана Senior Member Svetlana Tkachenko Join Date: Oct 2013 Location: Australia, Sydney Posts: 407 Rep Power: 14	I'm sorry, I think CFD-Post does not have an expression for "maximum of this expression over time". Go to CFX-Pre. Make it output the value of interest as a monitor. In CFX-Solver, save the user point monitor plot as CSV file. Do the post-processing using any tool such as GNU Octave, a spreadsheet, etc.

July 19, 2017, 03:00		#7
gbrajtm Member Dr Gurubasavaraju Join Date: Dec 2014 Location: Bengaluru India Posts: 77 Rep Power: 11	thanks, I will try out other alternatives. Светлана likes this.

July 19, 2017, 03:05		#8
Светлана Senior Member Svetlana Tkachenko Join Date: Oct 2013 Location: Australia, Sydney Posts: 407 Rep Power: 14	OK, keep everyone updated please. :-)

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