Behind a sphere

You want to perform an experiment that illustrates the wake behind a sphere falling in water at the point where the boundary layer undergoes transition from laminar to turbulent. (See Fig. 11-4.) If the sphere is made of steel with a density of 500 lbm/ft3, what should the diameter be ... 

Fig. 5.8 Volume of closed wake behind a sphere. Measurements of Kalra and Uhlherr (K2) and numerical predictions of Woo (W9).

Taneda, S. (1956). Experimental investigation of the wake behind a sphere at low Reynolds numbers. Journal of the Physical Society of Japan, 77(10), 1104—1108. 

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