Abstract
So far, many analyses and experiments of reattaching jet have been carried out for the models without splitter. And the effects of splitter on the jet are not yet sufficiently explained. This fact may prevent the usual analytical results from being applied to the practical fluidic devices with splitter.
Using a large scale model with splitter and one-sided wall (nozzle width=10mm, aspect ratio=3), the reattachment distance, the pressure distributions on the offset and the side walls, and the flow patterns were investigated.
From the experiments the followings were confirmed. There is a critical splitter distance (minimum splitter distance), beyond which the splitter does not affect practically the reattaching jet. The usual analytical results are valid for the device with aspritter distance larger than the critical distance. This distance is not necessarily equal to the distance from the nozzle exit to the point where the jet outer edge intersects the extended nozzle centerline. When the control flow is applied keeping the splitter distance less than 1.25 times the critical distance, the splitter suppresses the increasing of the jet radius of curvature and damps the bubble pressure rise. However, when the splitter distance becomes more than 1.5 times the critical distance, the reattaching jet is scarecely affected by the splitter. Therefore, the usual analysis for such device may give some practical results, even if the existence of splitter is neglected.
These results obtained with the one-sided wall are applicable to the usual wall reattachment fluidic device with a considerably large offset on the unattached side of the jet.
