Experimental Investigation of the Problem of Surface Roughness (1937)
NASA Technical Reports Server (NTRS) · leaf 52
N.A.C.A. Technical Memorandum Ho. 823 Fige.13,15 Figure 15.- The nondimeneional velocity distribution for the long angle reughneee, k=0.32. =0.31; = 0.30 cm.
NASA Technical Reports Server (NTRS)
Internet Archive · NASA Technical Reports · Public domain (US government work). Free to use for anything.