On the measurement of skin friction from the turbulent velocity profile

Effects of sandpaper roughness and stream turbulence on the turbulent boundary layer

“…There is most encouraging support for Coles' proposal The two chain lines show the fitted law for the viscous of a value of 0.41 [6 ], or for that of 0.405 [16 ], for the sublayer and for the log law, which latter alone is repsmooth surface now being applicable for all the boundresented by ary layers over these rough surfaces and under stream turbulence. The mean value of k for this set of results is…”

“…Then, using the present correlation for the momentum thickness. Using the corcurve fitting technique [12], a generalized form of the responding values of u t in the profile fit resulted in the Musker velocity profile was fitted to the data of each values of k listed in column 8. profile [15,16 ]. A typical example is plotted in Fig.…”

“…A tabulation of the results of curve fitting for a selection of ten profiles is given in Table 1. All these results are, Column 9 of Table 1 gives the values of B and these in roughness height, the viscous sublayer and the trans-To these results has been added the result for the smooth ition curve are extended, whereas the reverse occurs in plate [16,18]. There seems to be no systematic effect of the pipe flow.…”

“…The present curve fitting technique determines the There have been several attempts at correlating the origin for the ordinate y above the rough surface [16 ]. value of B for the boundary layer [19] and the pipe flow…”

“…9. Values for the smooth surface are included shift in the value of B that are arithmetically of the same [16 ]. As y+ 0 is a small quantity to determine from the order as the present ones but, as just pointed out, traverses and as it also can embody the uncertainty in algebraically of opposite sign.…”