Kathryn Sparrow, Dubravka Pokrajac, Dominic A van der A


This experimental study consists of a series of full-scale experiments involving oscillatory boundary layer flow over an impermeable bed and a permeable bed. Velocity measurements have been obtained through particle image velocimetry, and the effect of bed permeability on the velocity profile, phase lead, boundary layer thickness, bed shear stress (as estimated by fitting the log law), and finally the resulting friction factor is presented. For our rough turbulent flows over a permeable bed it has been found that the friction factor is increased by up to 36% and that the friction factor also demonstrates a dependence on Reynolds number.


oscillatory flow; boundary layer; permeable bed.

Full Text:



Breugem, W. P., B. J Boersma, and R. E. Uittenbogaard. 2006. The influence of wall permeability on turbulent channel flow, J. Fluid Mech., 562, 35-72.

Conley, D. C. and D. L. Inman. 1994. Ventilated oscillatory boundary layers, J. Fluid Mech., 273, 261-284.

Finnigan, J. J. 2000. Turbulence in plant canopies. Annu. Rev. Fluid. Mech., 32, 519-571

Jensen, B. M., B. M. Sumer. and J. Freds√łe. 1989. Turbulent oscillatory boundary layers at high Reynolds number. J. Fluid Mech., 206, 265-297.

Jonsson, I. G. 1966. Wave boundary layers and friction factors, Proceedings of 10 th International Conference on Coastal Engineering. ASCE, 127-148

Jonsson, I. G. and N. A. Carlsen. 1976. Experimental and theoretical investigations in an oscillatory turbulent boundary layer. J. Hydraul Res., 14, 45-60

Kamphuis, J, W. 1975. Friction factor under oscillatory waves, J. Waterw, Port, Coastal and Ocean Eng. Div 101(WW2), 135-144.

Kong, F. Y. and J. A. Schetz. 1982. Turbulent boundary layer over porous surfaces with different surface geometries, AIAA paper, 82-0030.

Manes, C., D. Pokrajac, V. I. Nikora, L. Ridolfi and D. Poggi. 2011. Turbulent friction in flows over permeable walls, Geophys. Res. Lett., 38. L034002.

Nielsen, P. 1992. Coastal Bottom Boundary Layers and Sediment Transport, World Scientific.

Raupach, M. R., J. J. Finnigan and Y. Brunet. 1996. Coherent eddies and turbulence in vegetation canopies: the mixing-layer analogy. Boundary-Layer Meteorology, 78, 351-382

Sleath, J. F. A. 1987. Turbulent oscillatory flow over rough beds. J. Fluid Mech., 42, 111-123.

Steenhauer, K. 2010. An experimental and numerical study of surface-subsurface interaction for bore-driven swash on a coarse-grained beach, PhD thesis. University of Aberdeen.

Swart, D. H. 1974. Offshore sediment transport and equilibrium beach profiles. In Publication No. 131 Delft Hydraulics Laboratory

van der A, D. A. 2010. Effects of Acceleration Skewness on Oscillatory Boundary Layers and Sheet Flow Sand Transport. PhD Thesis. University of Aberdeen.

van der A, D. A., T. O'Donoghue, A. G. Davies, and J. S. Ribberink. 2011. Experimental study of the turbulent boundary layer in acceleration-skewed oscillatory flow, J. Fluid Mech., 684,251-283.

Zagni, A. F. E., and K. V. H. Smith. 1976. Channel flow over permeable beds of graded spheres, J. Hydraul. Div., 102, 207-222.

Zippe, H. J., and W. H. Graf. 1983. Turbulent boundary-layer flow over permeable and nonpermeable rough surfaces, J. Hydraul. Res., 21(1), 51-65.