Partially confined multiple jet mixing

Results of hot-wire measurements in an incompressible partially confined jet issuing from an array of rectangular nozzles, equally spaced with their small dimensions aligned are presented. The quantities measured include mean velocity and the Reynolds stress in the two central planes of the jet at stations covering up to 115 widths (small dimension of a nozzle) downstream of the nozzle exit. For downstream distances greater than 60 widths, the flowfield is observed to be nearly homogeneous and the turbulence appears to be quite similar to that of a grid generated turbulence. Nomenclature AH = aspect ratio, LID D = width (small dimension) of the nozzle L = length (long dimension) of the nozzle L i = spacing between the plates 5 = spacing between the nozzles U = mean velocity component in the X direction Uc = mean velocity component along the centerline of the jet in the X direction U0 =mean velocity component in the exit plane of the jet in the X direction Us = mean velocity component of the secondary flow in the A'direction u = fluctuation velocity component in the X direction Mrms = ViP = rms velocity fluctuations in the X direction u =VwI/£/c (normalized rms velocity fluctuation