I still can't understand the DIFFERENCE between the two. In our project, we did an actual time-based experiment(solar heating) where in we gather data every 15 minutes for an interval of 45 minutes. But I'm just wondering if we could compare the actual data to the results of flow simulation that is not time-based? Because we couldn't do the time-based simulation since it takes a very very long time to finish.
Time based simulation has a much finer temporal resolution by default, and it has different convergence criteria. You should only use it if you are interested in capturing multiple "snapshots" of the flow field in time.