On the Distribution and Development of Mean-flow and Turbulence Characteristics in Jet and Wake Flows

The lateral distributions of various mean-flow and turbulence characteristics, as obtained from measurements in axisymmetric jets and wakes, are shown to conform to a new concept of self-preservation. The development downstream from the flow origin of representative cross-sectional values of the turbulence shear stress, turbulence normal stress, and the maximum mean-velocity difference, as well as the development of some nondimensional ratios thereof, is presented for the following free-turbulence flows: plane free jets and wall jets with ambient streams, axisymmetric jets in coaxial streams with different ratios of jet to free-stream velocity, and wakes behind a slender spheroid, a disk, a square plate, and a self-propelled body of revolution. The results indicate that in the case of axisymmetric free-shear flows, similarity according to the conventional definition is not even approached asymptotically and that the conditions of flow generation have a greater influence on the downstream flow development than has been assumed previously. (Author).