The flow file is fine. What kind of mesh do you have? (# elements, boundary layer?, regional refinement? radius based?, etc)

You would need to make the period a third of your simulation time to repeat it 3 times within the simulation.

If you're specifying the entire file (meaning it is not periodic), you should pad the file on the end with the value you had at the last time step (otherwise it tries to interpolate to the beginning). 1 second should be plenty. Don't touch the period, let that generate automatically from the file, a...

Sometimes SV fails to create data files because it has too many elements or too many points on the flow files. Try tweaking both of these, hopefully this works.