Turbulent Flows Past Boundaries with Small Streamwise Fins

by John F. Kennedy, (M.ASCE), Dir.; Inst. of Hydr. Res., Univ. of Iowa, Iowa City, IA,
Sheng-Tien Hsu, (A.M.ASCE), Res. Engr.; Tennessee Valley Authority Engrg. Lab., Norris, TN,
Jung-Tai Lin, Res. Sci.; Flow Res., Inc., Seattle, WA,

Serial Information: Journal of the Hydraulics Division, 1973, Vol. 99, Issue 4, Pg. 605-616

Document Type: Journal Paper


An experimental investigation was conducted to determine the effect of small streamwise fins on the average boundary shear stress of turbulent flows in conduits. The experiments were performed in a rectangular cross-section wind tunnel equipped with a dynamometer-supported shear plate which permitted direct determination of boundary shear stress. Tests were made for a smooth boundary and three different finned surfaces. It was found that over the range of velocities investigated (60 to 100 fps [18 to 31 m/s]) approximately, corresponding to Reynolds numbers of 2.5 x 10FRUS5TUTF to 4.1 x 10FRUS5TUTF, the fins increase the average boundary shear stress on the projected area. The average shear stress on the actual boundary surface may be decreased, but the reduction is more than offset by the increased surface area.

Subject Headings: Shear stress | Boundary shear | Turbulent flow | Domain boundary | Shear flow | Conduits | Cross sections | Wind tunnel

Services: Buy this book/Buy this article


Return to search