Supplemental Studies of Reattaching Jet Flows in Fluid-State Wall-Attachment Devices

摘要

Experimental studies were conducted to provide information regarding the characteristics of the power jet flow upstream of reattachment and the recirculating flow in the separation bubble enclosed by the power jet for wall-attachment type digital fluidic devices. The studies included a determination of the velocity profiles in the jet and recirculating flow at various stations (both streamwise and spanwise) upstream of reattachment for double-boundary-wall configurations at subsonic jet Mach numbers without receivers located downstream of reattachment. A limited amount of data was obtained with a diffuser located on one boundary wall downstream of reattachment. Supporting analytical studies were also conducted to evaluate a new recompression criterion which can be employed in jet reattachment analyses. The results of the analytical studies showed that a recompression criterion which utilizes the generalized velocity profile found to exist at the initiation of recompression can be employed conveniently in reattaching jet analyses. Reattachment locations computed from a previously developed reattaching jet analysis revised to incorporate the new recompression criterion were found to be in reasonable agreement with measured reattachment locations for a range of control flows. (Author)