June 23, 2021 at 10:27 pmTryingMyBest1232Subscriber
I've been trying to run a transient simulation that uses Fluent's solar ray tracing that needs to be run for a few days. Unfortunately, after the first 24 hours, the sun doesn't rise again and the solar flux remains 0 forever. Can anyone give me any help or advice with this?
I tried to run the first 24 hours, then set the time in the solar calculator to 00:00 and run the next 24 hours of the simulation without re-initialising but this only seemed to use the right sun direction vector for 1 time-step (unless I did something stupid).
I'm quite new to fluent so sorry if this is something easy. If not, a work-around would be highly appreciated.
ThanksJune 24, 2021 at 9:50 amRobAnsys EmployeeYou'll need to reset the solar load for the new time as it's not designed to be run over many hours.
June 24, 2021 at 10:00 amTryingMyBest1232SubscriberThis is what I tried doing. After 24 hours I stopped the simulation and set the time in the solar calculator to 00:00 and then clicked apply. When I restarted the simulation it worked for one iteration but then the solar load never changed. Did I do something wrong?
June 24, 2021 at 10:07 amRobAnsys EmployeeTry 00:01 and see. Given it's dark I'm not sure what the solar calculator will do.
June 24, 2021 at 10:19 amTryingMyBest1232SubscriberI have just tried this and I also reset the flow time to 0 to see if this would fix the issue but I'm not having any luck. I'm sure I'm just making a silly mistake but nothing I try seems to be working.
June 24, 2021 at 12:27 pmDrAmineAnsys EmployeeCAn you a try a dummy run with very large time step size just to control the solar load properties and whether the sun goes up in large time intervals.
June 24, 2021 at 12:59 pmDrAmineAnsys EmployeeWhat about running following test: From the time in your day run till the end of the day. Then start the second run with the new day and time 00:01 (new session, reading case and store d data).
June 24, 2021 at 1:01 pmDrAmineAnsys EmployeeThe flow time might be required to bet setup back to zero!
June 25, 2021 at 6:51 pmTryingMyBest1232SubscriberI did some testing as suggested and found the method I was using didn't work with a 150s timestep but did with a 180s timestep. Very weird! For those with similar issues the process is:
Run day 1
Set solar calculator to 00:00 and apply
Reset flow time in console with (rpsetvar 'flow-time 0)
Run the next 24Hrs of simulation and repeat
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