Copyright (2005) Cambridge University Press. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Cambridge University Press. The following article appeared in J. Fluid Mech. , Vol. 546, pp. 123--152, 2006 and may be found at M. Wei, and J. B. Freund, A noise-controlled free shear flow, J. Fluid Mech., Vol. 546, pp. 123--152, 2006.