Solar calculator provides wrong sun direction for runtime longer than 24 hours
Summary
When running a transient simulation with Solar Load and sunDirTracking, the solarCalculator returns the wrong sun direction when the runtime goes over 24 hours. The sun trajectory is correct for the first 24 hours, and then stays west for the following days.
Steps to reproduce
Run a case over a total runtime of more than 24 hours, with Solar Load enabled and with an obstacle to generate projected shadows.
Example case
The following case is a simple box with an opaque ceiling and an opaque floor, and transparent sides. The total simulated time is 48 hours. When displaying qr on the ground, the projected shadow of the ceiling on the floor is correct for the first 24 hours (from west to east, as the sun moves from east to west) and wrong for the last 24 hours (stays east, as if the sun rose and set west).
This case solves only the radiation, every other equation is turned off to allow a 1-hour timestep.
What is the current bug behaviour?
The solarCalculator predicts a sun staying west when the runtime goes over 24 hours.
What is the expected correct behavior?
The sun should move from east to west even for runtimes longer than 24 hours.
Environment information
- OpenFOAM version : v2406
- Operating system : Windows 10
Possible fixes
Adding a modulo function at line 95 of solarCalculator.C seems to take care of the issue without any additional effects:
scalar LST = startTime_ + (runTime/3600.0) % 24;