memory management #4
Description
Memory management:
on branch master, maybe delete the array VORT and replace it by WORK (it is confusing to call it vort since it is actually a work array. at mid-term maybe have only "workc" and "work" as work arrays
on branch FSI, two issues: the pressure requires a workc array, but this should be fine once the new master is merged in (use workc then). the iterative FSI scheme requires an additional uk_old vector, but I'm afraid thats inevitable
its is also not entirely clear if we actually need 3 complex arrays for sponge