Two parallel plane jets: mean flow and effects of acoustic excitation

 The flow field generated by unventilated two parallel jets has been investigated using LDA. The two nozzles each with an aspect ratio of 24 were separated by 4.25 nozzle widths. Results show that a recirculation zone with sub-atmospheric static pressure was bounded by the inner shear layers of the individual jets and the nozzles plate. It was shown that the two-dimensionality of the flow was greatly enhanced by the installation of side plates and that the flow was independent of Reynolds number between 8300 and 19300. Acoustic excitation introduced at the outer shear layer mode has been shown to reduce the size of the potential core, recirculation zone, merging length and combined length but enhance jet spreading, streamwise velocity decay and volume entrainment. Received: 18 November 1994/Accepted: 26 July 1996