We have all seen the swirl devices that move water side to side. Would you get the same results with fan rotating 90 degrees from the surface then down. Using multi flat outlets across the tanks front length.
Not quite following the "wide fan nozzles". You mean the water flow would be dispersed sideways a lot rather then coming out straight and more forcefully?
Sounds like this would be good for a bare-bottom tank to help sweep detritus off the bottom and back into circulation (good).
Not sure how much the corals would like water coming straight down at them. Their normal tendency (broad generalization warning!) is to grow toward light (or at least maximize light exposure) with polyps angled to catch (mostly) horizontal flow. So light and flow are generally coming from different directions. Light and frow from the same direction could be evolutionary!