CONGO GA optimization
 

Hi Dr. wang,
if I want to run a GA cases with the default merit function, does it means I can use the merit.in file to specify the setting, otherwise, the merit.in file is unnecessary for a user defined merit function case? Without using congo,
I turned on the ga_flag in inputs.in file and ran the case, it created one outdata.0 file, in which some performance parameters are written. Can you tell me the names and units of these parameters?

Thanks

Jack,

Can you tell me the version of your CONVERGE and UDF?
Thanks,

Yunliang

Thanks. The version i am using is converge 2.2.0_101915.

The default UDF for user_ga_merit.c was changed to work automatically from v2.2 on by creating a ga_output file with ISFC, NOx, Soot, PCP, and indicated Power.
However, the default ga_merit_function.c in the main code was not updated accordingly. You can use the UDF user_ga_merit by turning on user_ga_merit_flag in udf.in
We will fix this soon.
The merit.in is required to set up a default merit function using the variables in the ga_output file.

Thanks,

Yunliang

Thanks, I got it. But it looks like the default UDF for user_ga_merit.c only changes the output performance variables in ga_ouput file. So it means the merit function is still use the default as the description in CONGO summary_r4, right?
one more question, i want to add a peak pressure rise rate(PPRR) into the ga_output file, if i could possibly get a completion signal of runing case, use which i can write code to read thermo.out file than calculate the PPRR and write into the ga_output file.

Thanks

Jack,

You can read through the UDF user_outputs.c to see how we calculate the region-dependent variables like pressure, temperature etc. You can do the same thing in your user_ga_merit_function.c. You can save the pressure at last time as cylinder_pres_last for example. Then you should be able calculate the pressure rise rate according the pressure at the current time step and the previous time step.

Thanks,

Yunliang

Thanks. I see, sounds like it is a better way than my idea. I gonna try it.

CONGO.in File
 

Dear Dr. Wang
I am going to optimize parameters like ISFC, NOx and Soot in RCCI engine through CONGO. I was wondering if you could please provide me with CONGO.in sample file.