Consider a 2-dimensional turbulent jet emerging into an ambient fluid at rest, and contrast it to the laminar jet analyzed in Ex. 15.3.

(a) Find how the mean jet velocity and the jet width scale with distance downstream from the nozzle.
(b) Repeat the exercise for a 3-dimensional jet.

Data from Exercises 15.3.

Consider a narrow, 2-dimensional, incompressible (i.e., subsonic) jet emerging from a 2-dimensional nozzle into ambient fluid at rest with the same composition and pressure. (By 2-dimensionalwemean that the nozzle and jet are translation symmetric in the third dimension.) Let the Reynolds number be low enough for the flow to be laminar; we study the turbulent regime in Ex. 15.7.We want to understand how rapidly this laminar jet spreads.