Date of download: 12/20/2017 Copyright © ASME. All rights reserved. From: Discussions: (1) “On the Axisymmetric Turbulent Boundary Layer Growth Along Long Thin Circular Cylinders,” (Jordan, S. A., 2014, ASME J. Fluids Eng., 136(5), p. 051202) and (2) “Understanding Tow Tank Measurements of Total Drag for Long Thin Circular Cylinders,” (Jordan, S. A., 2014, ASME J. Fluids Eng., 136(3), p. 031205) J. Fluids Eng. 2015;137(3):035501-035501-3. doi:10.1115/1.4029329 Figure Legend: Comparisons between experimental measurements and prediction (1) of Afzal and Singh [3]—δ/a=0.045(x/a)0.746 for Rea=14,200 and prediction (6) of Jordan [1]—δ/a=0.259(x/a)0.510 for same value Rea=14,200, for axial growth of turbulent boundary layer thickness along a long circular cylinder. The power index 0.510 in Ref. [1] is nearly a value of boundary layer thickness δ~x0.5+… along a circular cylinder due to laminar flow [7] rather than turbulent flow [1,6].